On the radiator that was in the overheating truck. I've been the good boy and flushed my radiators and changed the coolant and did all the things you did, and my core still got clogged up, mostly out of sight of the filler neck. When I did the above test, my outer core areas were dead cold, even tho the tank was a constant temp all the way across. The lack of cooling are led to a chronic overheat under load in warm ambients.

Ah! The overheating is in my 3.0L to 3.5L conversion. I been running a (huge) new Griffin aluminum radiator in that for the last couple years so I don't know how much help those readings would be. Although, they'd be interesting in a comparison between stock and the Griffin radiator. I have a thermal reader so that's not an issue. Problem is I'd have to tear out the entire radiator assembly, take the fans off and put it all back and I don't have the time right now.

Also, my overheating problem isn't radiator related - its engine timing. The 3.0L ECM has about 2-8 degrees too much timing for the 3.5L engine design. As I've said before, the difference between a Mitsu 3.0L and 3.5L is the same as between a Chevy small block and a Pontiac (not the GM post-'74 "Pontiac" engines, but the real '67-'74 Pontiac engines). You can't run 40 degrees timing in a 3.5L and you sure as hell can't in a Pontiac. The MAX timing in my '03 3.5L Limited is about 34 degrees so that gives you and idea how 'off' the timing is between the ECM and what the engine can take.

I'm still working on the timing map(s) and I'll post it as well as some screen shots here in a bit. There's no question in my case what the overheating is. I'm only modifying fuel delivery and timing. I can disconnect the F/IC and my overheating problem is instantly back (and it runs like crap, relatively speaking); plug the F/IC back in and the engine temperatures are right back down to 192-199 and it runs like a top.



Yea, that'll happen. You have a water problem. I have really hard water at my place. I can't use it for anything; it'd trash a battery or cooling system in pretty short order. That sounds like the problem you're having.

My suggestion is drain and flush the entire cooling system, either get a new, clean radiator or have your existing radiator hot tanked. You're not going to be able to do a good job yourself of getting scale and crud out of a radiator core.

Then use 50/50 pre-mix or buy a few gallons of distilled water from the store mix your own. I'd also suggest a bottle of BG Super Cool or Red Line WaterWetter. BG is cheaper here and that stuff is awesome.

Our radiators are down-flow. I'm not particularly impressed with the design. I've noticed for years that the passenger side of the radiator stays cooler than the driver side where the outlet is. Coolant flow isn't even. That's why I made the primary cooling fan on my electric setup the driver side and the secondary the passenger side fan.

Its possible to design and build a more efficient radiator, but its not worth the money and aggravation. The big Griffin I have is already overkill. Our vehicles don't need that much cooling. If wheeling a 7000 lbs modified Sport in Moab 110 degree weather with the A/C on without going above 199 isn't proof, I don't know what is.

Edward

Excluding bench flow testing and individual port EGT, is there a way to tell if you have a leaky injector(s)? Fed '97s only have the front and rear O2, so I can't use that to narrow it down.

Edward

I spent Saturday swapping out my hood - pin mounts broke last Thursday - and the MAF. Took it for a 240 mile drive in the Rockies and did a bunch more tuning. I've made improvements but now I have another issue. I think.

So, after reworking the timing map and shaving off another degree or two, it mostly runs great. So, I'd say about 90% good. I think with a bunch more tuning I could get that up to 93%. However, the current other 10% sucks.

Assuming this is not being caused by a bad MAF or MAP - and I'll know shortly 'cause I have a new MAF showing up this week and a new MAP in the front seat - I think I've hit the wall with the stock ECM. I think the problem I'm seeing is from pulling too much timing. I don't know for sure and I'll do some testing tonight on the way home. However, if that's the case then this idea is dead. <img src="/forums/images/graemlins/frown.gif" alt="" />

While I can get the AEM to work pretty dang well in Denver and pretty dang well at Eisenhower Tunnel @11K ft, I'm having a hell of a time getting both. And, I haven't even started on the off-road tuning. <img src="/forums/images/graemlins/frown.gif" alt="" />

So, I'm keeping my fingers crossed its the MAF/MAP that's causing the problems. At this point, it's undrivable until the vehicle warms up to operating temps. Bucks and seems to cut out like crazy and there a wierd 'miss' sometimes at really light cruise. Sigh. <img src="/forums/images/graemlins/frown.gif" alt="" />

At this point, though, I've pretty much come to the realization that there is NO WAY that this solution will work at sea level. The lower you go in altitude the less timing is needed and there's just way too much. The only feasible solution is really to go with a MegaSquirt, take the timing completely out of the ECM's hands, and let the MS do all the timing. At which point you are in for a ton of tuning and dyno time to build a custom timing map. The MS could still fill the piggy-back function for reducing fuel, but timing would be solely on the MS.

Anyway, I'm re-approaching the ECM swap idea. Danny's thread got me thinking so I did some research into the Montero. I THOUGHT they did a Montero with the 3.5L and 5-speed manual but I was wrong. '96 was in fact the last year apparently and those ECMs are not OBD-II - which means I can't pass emissions.

As I understand things, '99 is when they transitioned to PCM - integrated ECM/TCU - which just puts me right back to the problems I had with using the '99 Sport PCM. Can't get past all of the TCU stuff that the ECM actively interfaces with.

So, I did some research on the '97 3.5L SOHC Montero ECM (MD338137) and it LOOKS like its virtually identical in functionality to the '97 Sport ECM. Time frame matches, too. Late '96 to early '97. I would have liked to go with a '98 ECM for possibly better OBD-II, but I can't tell which ones have anti-lock or which don't or if they all do. No way am I going to try to fake out ABS in an ECM. <img src="/forums/images/graemlins/frown.gif" alt="" /> And, I don't know if they expanded integration with the TCU in '98 - and I don't want to find out. As far as I'm able to tell so far, the extent of the '97 ECM/TCU integration consists of one wire which is a 'bus' line that the ECM uses to make sure the TCU is still 'there' periodically. Same as the '97 Sport. Tech doesn't think if that's disconnected the ECM even triggers any type of code. That'd be perfect - just leave it unplugged and ignore.

I have a set of '97 Montero FSMs on the way and an ECM. Once I get the manuals I'll start cross referencing the ECMs and see where I end up. I suspect that at the very least I'll need another Boomslang harness because all the pin locations are not identical to the Sport ECM but at this point, after talking to the tech, I don't expect too much more. Hah. Famous last words. <img src="/forums/images/graemlins/frown.gif" alt="" /> At least it uses the same 'green' plugs as the '97 Sport so cross-referencing will be cake. I also got an ECM with the four plugs still attached so I can see which are populated and which aren't very easily.

The only part I really don't like, provided this approach works, is that the timing will STILL be for an automatic, not a manual. And, I do know that there are small differences between the maps. However, at least they won't be enough to cause more than slightly degraded gas mileage. And 'slightly degraded' is probably relative. With 240 miles of nasty storming windy mountain driving, I ended up getting 17.9 Mpg. In an almost 6000lb vehicle with solid axles and 35" M/Ts and the profile of a block house. Not my normal 19-20 back-and-forth from Moab, but not horrible.

Sucks to have to start looking at going almost back to square one, but I'm fast loosing confidence in the current solution. I MIGHT be able to get away with an off-road map and a street map, but I'm not even sure that'll work now. Sigh.

One thing I've absolutely for sure settled - there is NO WAY you can just run a 3.5L on a 3.0L ECM/PCM. Not even with knock sensors. There's more timing than the knock sensor circuit will be able to deal with and the ECM is going to start dumping gas to try and suppress knock and what you'll end up with is a pig that gets 14 Mpg - maybe, if you're lucky. Sucks. I didn't think it'd be quite this bad. Can't believe I'm pushing 8 degrees in parts of the map now. <img src="/forums/images/graemlins/rolleyes.gif" alt="" /> <img src="/forums/images/graemlins/frown.gif" alt="" />

And if you put a 3.0L on a 3.5L ECM, you're going to wish to God you'd never been born 'cause it'll be such a pig you'll never get it moving. Unless you turbo or super charge it. That might work out pretty well.

Edward

I reverted to a previous map from Saturday where the max reduction in timing is 6 degrees and everything seems to be back to normal. Having seven degrees reduction on the 'street' map was causing all kinds of weirdness. That also got rid of the problem I was having during warm-up.

I don't know if I can pull more than that on a map strictly for off road, or if I'll get the same problem. I'm guessing I'll have the same problem. Since there's nowhere to go off road here in CO right now - mountains are buried in snow - it may take a month to get to this - if I get to it at all.

I don't know what the current map will do in 100 degree summer weather, but in 20-60 degree range it works pretty well. Actually, very well. If the F/IC is still installed next month, this may basically be the map I run in June. It'll be interesting to see how it works with a drop to 4K from 5-6K in altitude and a 30 degree boost in temps.

Here are the timing maps from the 1997 3.0L (rev 2 ECM). These are generated from a 240 mile jaunt in the Rockies. The logging software split them into sections (sessions), but its all the same drive with only one key off stop. Its in PDF form - I figured 35 graphs and tables was a bit much in a forum.

There are four sets. Minimum, maximum, average timing and standard deviation so its visible just how much swing there is in timing. THAT highlights the problem I've been facing if nothing else does.

1997_Montero_Sport_LS_4WD_3.0L_5-Speed_Manual_Transmission Timing Maps

If nothing else, the charts and tables gives an interesting look into the ECM.

Edward

Well, it sounded like a good idea ....

After replacing all the electronics on the engine (except the MAF and IAC, which will go in this weekend) and both O2 sensors, I've got it back to running virtually like new. I need to replace the CAT, too, here shortly. Hoping that'll finish straightening out my fuel trims. Overall, it runs like a top. Lots of power - lots more torque than the 3.0L, that's for sure.

Problem is, that fixing everything has just created more problems. The better the engine runs - the more timing the ECM dumps in. Swapping back to the 5.38s got my ECM back to sane, but the ECM adds more timing because engine load isn't as high. And, the more the temperatures fluctuate, the more impossible it is to compensate with a static map. Maybe I could do some more by tweaking the O2 to run the engine a tad richer, but that's at best a poor band-aid.

I'm reasonably certain that I could get this to work if I did like the DSM/3g/EVO/GT guys and forced it into OL-Drive all the time, but that's a pretty stupid idea for a street driven vehicle. Might as well just yank the F/IC and put a MS in and give it full control of the timing and fuel.

Hate to say it, but this idea is dead. <img src="/forums/images/graemlins/frown.gif" alt="" /> I have to give AEM credit. The F/IC is an awesome box. It does exactly what they say it will and it does it well. If I were running a turbo or supercharger, this would be my first choice. But, its just not working out as I'd hoped. There is such a huge variation in altitude and temperature here in CO that unless you have something that makes constant adjustments - its just not workable.

On the plus side, its working out enough that I'm not going blow the engine up and it helped me troubleshoot a bunch of issues I didn't even know I had. But, that's about as far as it goes.

So, off to transplanting in a different ECM. Again. <img src="/forums/images/graemlins/frown.gif" alt="" /> Since the 3.5L Montero Sports only came with PCMs - and swapping one of those in hasn't paned out - I'm moving over to the Montero ECM. I've gone through a bunch of Montero stuff with the help of others here on the forum. (Thanks, guys!!) The following is what I've come up with so far ...

3.5L SOHC A/T Montero (NOT SPORT!) ECM (FED)
1997 MD338137
1998 MD343513
1999 MD361885
2000 MD365261

The 1997 is the 92 pin (4-plug) connector, just like the '97 Montero Sport M/T (green).

The 1998-00 is the 100 pin (3-plug) connector, like the '98/99 Montero Sport 3.0L A/T (black).

These four are all ECMs - no integrated TCU (Transmission Control Unit).

The '00-05 Montero Sport 3.0L and the Sport '99-05 3.5L use the 130 pin (4-plug) connector like the '01+ Montero, and these are PCMs - integrated TCU (besides other things, hence the extra 30 pins)

A quick tell-tale to distinguish between an ECM and PCM - ECM = 92/100 pin connector and PCM = 130 pin connector.

As best as I can tell, these break down into '3' groups. '97, '98/99 and '00. I THINK - based on my research - that there are internal programming differences which MIGHT make using the '98/99 or '00 preferable to the '97, but I have no actual evidence at this time. It'd be interesting to find this out, though. There's a significant difference between the Sport M/T rev 1 '97 ECM and the rev 2 '97 ECM.

So, back to the drawing board, so to speak. I now have a Montero '97 and '98 ECM. Sets of FSMs for both are on the way - they're supposed to be in tomorrow.

I've already gone through the '98 electronic FSMs and generated a spreadsheet with the pin-outs and so far nothing earth-shattering has shown up. So far this is it ...

Not sure what these do yet (or what affect they have if missing):

1. ABS Control Unit (pin 66)
2. ELC-4 A/T Control Module (pin 87) (C-140 pin 45) - engine coolant temp signal
3. ELC-4 A/T Control Module (pin 88) (C-140 pin 46) - MIL request signal

No equivalent on M/T:

1. Park/neutral position switch (pin 67)
2. 4WD Operation detection switch (pin 65)

Unless the P/N connection does something stupid like keep your vehicle from starting, I think it can be left unconnected. Not sure if it actually triggers a code and CEL. I don't think so.

The 4WD Operation/detection switch just grounds to the t-case when closed (in 4WD). The 4WD Operation/detection circuit does something - this has nothing to do AFAIKT with dash lights, t-case, transmission operation. Could be something as simple as a trigger for limiting speed in 4WD or it could trigger changes in fuel/timing maps OR do something funky with the IAC. OR it could be a trigger for a whole bunch of things. I can think of half a dozen things just off the top of my head. <img src="/forums/images/graemlins/frown.gif" alt="" /> If its necessary, at least there's a dirt simple fix. Just add a switch.

Once the FSMs show up, I'll confirm what I have against the wiring diagrams (which are missing in the electronic FSMs).

I'll start with the '97 ECM. Put together the pin-out diagram and then have Boomslang do up a conversion harness. The '97 ECM I have has the plugs still attached so I can confirm that I'm not missing pins - something(s) not documented in the FSMs.

If I can get that working ok, I'll move up to the '98 ECM (since I have one) and see if there's any difference. But, first, I need to get something working. Otherwise, it'll be time to start considering yanking out the 3.5L and going back to the 3.0L. <img src="/forums/images/graemlins/angry.gif" alt="" /> <img src="/forums/images/graemlins/frown.gif" alt="" />

Guess I could consider swapping in a M/T SOHC 3.5L ECM from a '96. Maybe that would work if there is such a beast. I'd still have to swap out for emissions testing, but in theory I'd have something that works 99% of the time. I think I'd be more inclined to just go back to the 3.0L. <img src="/forums/images/graemlins/frown.gif" alt="" />

As an aside, I found documentation in the '98 Montero FSMs that explicitly says that the pre-CAT and post-CAT O2 sensors are BOTH used in calculating long term fuel trim (LTFT). Which means that a bad CAT or no CAT at all will screw with fuel delivery. Based on my experiences over the (many) years, Sports are no different.

Link to more Montero stuff related to this thread ...

Montero 3.5L 5-speed?

Edward

Ok. I've gotten this far, but now I need some help.

I went through the '97 Montero FSMs and went back trough the '97 Sport FSMs. I went through the harnesses and noted every pin that's populated on the Sport M/T harness as well as the Montero harness. Amazingly enough, 99% of the pins on both the Montero ECM and Sport harness match up.

This is what I have so far ...

I'm missing Montero ECM pins 7, 60, 52 and 59 on the Sport harness. 7, 60 and 59 are obvious - the harness is for a M/T and these are A/T specific.

I have no idea what Montero ECM pin 52 is for. I don't have anything like this on the Sport. I haven't found anything in the FSMs. What is this? It doesn't go anywhere; its just a single wire connector.

There seems to be no equivalent on the Montero ECM to pins 41 and 77 on the Montero Sport harness. The only reference to the evap ventilation solenoid and fuel tank differential pressure sensor is for the Montero CAL ECM. Did the FED '97 Montero really not HAVE these??? The other evap and EGR stuff is there - how do they not have those??

The ONLY non-M/T-A/T related pin that appears to be different between the Montero and Sport is pins 9 and 32, respectively. The evap purge solenoid.

The Ignition Switch-ST GND (M/T) or P/N switch, pin 91, is on both the M/T and A/T Montero and Sport and AFAIKT, do exactly the same thing. The M/T has the clutch pedal switch and the A/T has the P/N selector switch - the effect is the same.

• 
  Montero -- Desc
  7 -- ELC-4 A/T Control Module C-140 pin 45; Engine coolant temp signal
  60 -- ELC-4 A/T Control Module C-140 pin 46; MIL request signal
  52 -- Ignition timing adjustment connector A-44
  59 -- 4WD Operation detection switch
  9 -- Evaporative emission purge solenoid
  
  Montero Sport -- Desc
  41 -- Evaporative emission ventilation solenoid
  77 -- Fuel tank differential pressure sensor
  32 -- Evaporative emission purge solenoid
  
  Both -- Desc
  91 -- Ignition switch-ST GND <M/T>, P/N switch <A/T>

So, this is what I did. I already have my Boomslang harness for the AEM F/IC - which is just a straight-through Male to Female patch harness. I disconnected the AEM F/IC and installed the loop-back plugs so it'd just be straight through ECM to factory harness. Then, I wired pin 32 on the Sport harness side to pin 9 on the Montero ECM. Everything else matched, so I plugged the Montero ECM into the Boomslang - which then plugs into the factory harness.

I turned the key to on (not trying to start the vehicle) and everything seemed to come up. I got the MFI relay click and seemingly power to everything. Nothing started melting, at least. So far, so good. Then I tried to start it. No love.

The engine turns over and sounds normal. There's no weird noises or behavior. It just doesn't start - doesn't even TRY to start. Turned everything off, tried again a couple times and the same behavior each time. I have two Montero ECMs (from different sources) so I tried both - same with either one ECM. I removed the Montero and plugged in the Sport ECM and it immediately started. I let it idle for 3-4 minutes and then turned the vehicle off. Unplugged the Sport ECM and pluged the Montero ECM back in. THIS time it sounded like it was trying to start for the first several revolutions, but then went back to sounding the same as the first try. It sounds like its getting no fuel - how that can be I don't know since everything according to the FSMs matches up.

I've cycled the ignition on/off a dozen and a half times at least and tried to start it half a dozen times. Then I plugged my OBD scanner in and checked for codes and the drive stuff. There are no OBD codes and the only drive stuff that isn't cleared is the stuff you actually have to drive the vehicle to clear. Basically, it looks EXACTLY like my Sport ECM looks after you do a clear, before driving it for the first time.

I spoke to the lead tech at the dealership this morning and he was actually a little shocked that it didn't just start up. THAT makes me feel good. <img src="/forums/images/graemlins/frown.gif" alt="" />

I know 52 and 59 won't prevent the vehicle from starting.

9 <--> 32 work or I'd get a code. Either way, won't cause a no start.

41 and 77 shouldn't case a no start, I would think. They're there and powered, and routed to pins 41 and 77 on the ECM. I don't know if this is/or would cause a problem as I don't know what those pins ARE really.

7, 60 and 91 are the ones that bug me. I'm PRETTY sure that 91 is fine - that should work irrespective of whether its an M/T or A/T as the functionality of circuit at the end of the day seems the same.

7 and 60 ... I don't know. I don't drive A/Ts so I don't know WHAT these really do or don't do. 7 supplies ECT to the TCU and that's all AFAIKT. 60? I don't know ....

I am in desperate need of some insight and ideas at this point from the Montero crowd.

Edward

Update. Finally. I got sidetracked rebuilding the entire front end, new CM shafts, new 1 ton drag link, better Blue Torch high steer arm, different stabilizer, swapping gears back to the 5.38s from the 4.90s I was experimenting with, new custom soft brake lines all the way around and having the drive shafts rebuilt. Maintenance. Fun times. Still not done. Still have a anti-wrap bar and relocation of the muffler on my plate for this year. <img src="/forums/images/graemlins/frown.gif" alt="" />



I got a wild hair end of June and pulled my 8" IPF lights off the ARB bull bar. The ones that mounted above the winch in front of the grill.

Unexpectedly, this made a HUGE difference with the over heating problem. I never had problems with the lights before and they've been on my big Sport since about 2003. I know that there is an air flow issue with the Sports and the ARB bull bar. This isn't a giant secret. I fully expected to run across a problem when I installed the lights, but when nothing happened I figured I was good. Or, well, good enough. Running Moab in 105+ degrees with no issues on the highway or trail seemed like that meant everything was good.

So, I wasn't wholly blindsided when taking them off improved things on the highway. What completely floored me is that it made an enormous difference on the trail. There's no question of whether it was the lights, because nothing changed for a month before and nothing has changed since and ambient temps have been way up there. Before I couldn't take it off road in sub-freezing temps without overheating problems.

I think there are actually two issues here. One was the restriction of air flow through the grill by the lights at any speed (or no speed at all) and the other is the location of the engine. I mounted the 3.5L EXACTLY where the 3.0L is mounted - using a combination of the 3.0L and 3.5L mounts. The engine wasn't shifted forward or rearward at all. However, when comparing my '03 Limited AWD 3.5L, my stock '97 LS 3.0L and my big Sport with the 3.5L conversion, it's obvious that the 3.5L in my big Sport sits further forward. There is quite a bit of gap between the firewall and the engine. While not having actually measured, it looks like about 2". At least. Sure makes it easy to take the bell housing bolts out. The front of the engine is also noticeably closer to the fans. (which is why I can't switch back to the stock mechanical setup without rebuilding all my mounts and supports)

So, moving the engine closer to the fans restricts airflow through the fans - the air exiting the fans is slamming into the engine before it can bend and flow around. While apparently not enough on it's own to cause a problem, when combined with the restriction of the lights ... well, things just go straight to hell. My reasoning here is based on the fact that vehicle speed has no affect. As vehicle speed increases, so does air flow through the radiator, so the problem should gradually decrease - which is totally not the case. That's what's had the radiator people and everyone else I've talked to stumped. Now cooling behaves as one would expect.

Its interesting. Again, I never would have expected the lights to affect the cooling this drastically on the trail when the vehicle barely moving. If I let it run up to about 215 and flip the fans on it takes less than half the time for the fans to drop the temps into the mid/upper 190s. Less than two minutes at the extreme - more like a minute.

Ok. Moving on ...

I'm still running the AEM F/IC 8. I haven't had time to fiddle with the Montero ECM conversion in the last couple months so everything further is F/IC piggy back and the stock rev. 2 ECM.

I am partially wrong. I'd previously stated that there was never going to be a chance that doing the 3.5L conversion and running the F/IC would ever work. I say partially wrong, because I've managed to get things working to the point I can run in ambient temperatures in the high 90's on the highway in Denver and tool up and down the passes in CO in the middle of summer without the vehicle overheating.

That's taken removing the IPF lights and some tweaking of the on/off/high points on my SPAL fan controller. I changed the on for primary fan to 192, and the full on for both fans to 208/210. With this setting the ECT will run up to 212/213 or so (full open on the thermostat) and then drop down to 203/208 or slightly lower. This is in 70-80 degrees. If ambient temps are lower, everything just sits in the low 200s and then drop to the 190s the minute the load is off.

So, I seem to have the 6000+ ft. highway altitude problem licked. This doesn't work as well in Denver at 5000 ft. The lower the altitude, the worse the problem gets, which tells me that there's still an engine timing problem. The higher you go in altitude, the more timing you need and the lower you go the less timing.

I still want to drop the primary fan on to 190 or 188 to give me a little more draw at low 25-35 MPH in 2nd/3rd gear. It still warms up too much if you're stuck at that speed in that gear going up hill for an extended period, but the fan tweaks have steadily reduced that to the point that one more tweak should put that to rest.

I also think I've run across another problem with the F/IC specifically. I updated everything to the latest ROM releases. I've been running v1.10 since I installed it and that appears to have been 'a BAD THING'. Something go completely crudded up between the F/IC and the ECM so I pulled the F/IC and re-flashed it with both code bases (the FI, and timing/everything else ROMS) and re-uploaded my config. Then I repeated the process only putting the v1.07 code vs. the v1.10 code. The v1.10 code is apparently targeted at multi-pulse injectors - which the Montero and Montero Sport are not. It should work, but that doesn't seem to be the case based on my experience. So far the v1.07 code seems to be working better all around and it does appear that there's less ECT fluctuation.

I also changed my timing config to overall reduce the amount of timing I'm pulling by about 1/1.5 degrees. This SHOULD have made the overheating worse and there was evidence that it had, but changing to the v1.07 ROM seems to have put me back where I was with my unmodified timing config.

This is a good thing, because while my original config was working as far as reducing the timing and mostly eliminating overheating and massive coolant temp swings, it was enough to seriously hork up the ECM over time. Massive misses and stumbling at high vacuum/off idle which gradually degenerated into all over the place. I don't know what the interaction was there but it WAS NOT GOOD. <img src="/forums/images/graemlins/frown.gif" alt="" />

I'm leaving for UT and Moab this weekend for nine days so I'll be able to put some serious mileage on the current configuration and see what happens. I'm keeping my fingers crossed. I'm also hoping that I may be able to reduce the amount of timing I pull by maybe .5 or 1 more degree. I've already tested that - the ECM stays happy at that point.

Anyway, the reason I say 'partially' is because I believe I'm right on the edge of having this for real functional at 4500/5000+ ft altitude both on and off road, but I have serious doubts that this will work at sea level. I'll find out how good this works at 4000 ft here in a couple days since that's what Moab is at and it's still in the 80/90s there. I just don't think the amount of timing I pull will work at half that altitude and I know the ECM won't tolerate more.

So, I was wrong. I looks like the F/IC is a solution in some instances. As far as I can tell. How this works in the long run is still a question. Just 'cause it ain't apparently over heating doesn't mean that there isn't detonation going on and that drastically decreases the life span of an engine in the long run.

Overall, though, with the lights off the bumper, the v1.07 ROM and the new config, I can't complain. Even with the v1.10 ROM and new config, I took it up last weekend for 300 miles in the mountains in 30-55 ambient temps (half deflated tires, of course) and averaged 17.8 MPG and never went above 212 even going over Berthoud Pass at 50 MPH in third gear. Ran like crap with the crudded up ECM/FIC but still did very good. Previews two weekends with higher ambient temps and air in my tires put me at 18.5/19 MPG in the mountains.

I still think the ultimate way to go is with the Montero ECM and for people that are doing a 3.0L to 3.5L swap in an automatic, this should be easy. For a manual trans vehicle, this is a nightmare. I'm going to work on the ECM swap some more next month, but I have a gut feeling that I may never figure this out and my professional help (techs) are going away at the end of this month so I'll be on my own.

Ultimately, if the new ROM for the F/IC doesn't work and the ECM/FIC keep crudding each other up, I think I'll end up using the MS in a piggy-back config. That way I can take the timing completely out of the ECM's hands and program in what I want. CO changed their regulations not too long ago. They don't care about CEL unless its emissions related and don't appear to give a damn one way or the other about add-ons as long as the vehicle passes so I don't see using the MS for timing as being an issue anymore.

Edward

thanks for keeping us up to date on this all very good info. I do find it very interesting that the 3.5 sits further forward than the 3.0 in the sport line, i've only been apart of swapping the 3.5 into a gen 1 and this wasn't the case he had to use some hammer action on the fire wall but like i said thats on a gen 1.

Do you think hood louvers would help your cooling issues, if i understand correctly a proper placement can help pull air thru the rad at hiway speed i would think this would also work well with your electric fan setup. Then again maybe just better off cutting and moving back the whole drive train a couple inches rather than trying to work around the issue.

No problem.

If someone would have told me this I would have argued but the tech that did the swap is the one that pointed it out to me during and we compared it to a customer 3.5L that was next bay. Weird. I don't see how it's possible. All we did was cut the 3.5L block plate off the mounts and weld that to the 3.0L base plates - in the exact same location as the original plates were mounted. Even matched up with the old weld spots.

The 3.5L is out of a 2002 Montero Sport Limited. They double checked with the seller half a dozen times. The only ones that I've heard of having different mount locations on the blocks are some cars and minivans. ???



No, I don't think it'd actually help. I'm at the point where additional air flow or coolant system capacity doesn't get me anything.

I have two problems caused by too much timing. The first problem is igniting the mixture too early in the stroke. That just causes excess heat due to the stress caused by the engine fighting against combustion in the cylinder. That you can throw cooling at - up to a point.

The second problem is detonation caused by the first problem, which no amount of cooling will fix unless its very, very, very minor.

The first I've mitigated with the monster radiator, SAS (no sub-frame assembly therefore better heat exhaustion from the bay), removing the lights for better airflow and tweaking the electric fans to provide more airflow during which this is a problem. THIS I pretty much have licked. All the aforementioned and decreasing the timing overall with the F/IC.

The second - there's no way to fix that with cooling. Lots of people think they can dump in tons of timing and then do things like pull the thermostat or put in a monster radiator and lower the temps to where it doesn't detonate. Most of the time where people claim this works, it really doesn't. They're just eliminating the worst of the problem and masking what's left. Turbo/supercharger guys are great for this. They get rid of the worst of the problem so they think they're good and then can't understand what happened the second or third time they stand on it and blow the crank out the bottom of the engine.

The first I'm good with. Its not efficient. It creates a little more stress on the engine and burns a little more gas, but otherwise its liveable. The second is just bad. No mater how you try to look at it and that ultimately needs to be resolved the correct way - by pulling out timing.

Like I said, I think I've got it at my altitude but I'm on the hairy edge. The other reason I don't want to consider more cooling is that even before the 3.0L/3.5L swap, with the SAS it takes a long time to get to operating temperatures. When it starts dropping into the very low teens and single digits, on the highway ECT will drop below 190. Full closed on the thermostat is low 190s, so besides not much coming out of the heater, this is not a good thing for gas mileage.

Edward