I picked the owners maual out of this 94. It list 91 premium for the fuel on this one. This is probably on Franks thread , but just incase , here it is.
Just got a Chilton on Diamante for the ol' library. Gonna see all the different setup for ECU/Emmission wiring to see if I can use the Dia electric system. I doubt it though cause I don't know how to put the MAP on my plenum.

I have one of the "aftermarket" FSMs, as in doesn't look like the usual ones from Mistu. I haven't organized it and posted to MisubishiLinks yet. Let me know ir you want is sooner and I can zip the whole thing and upload that way.

Look at it and see what it does and what you need to do. All it does is read intake manifold pressure - actually the lack of it.... if you consider 1 Bar as the base. <img src="/forums/images/graemlins/wink.gif" alt="" />

Frank

I was wrong about the MAP. My 89 doesn't have one,,and I'm not sure how ours measure pressure in the plenum , maybe it doesn't have to, just curious.

The thing on the Dia. Plemun is called "variable induction contol servo". It does report directly to the ECU. It sits at the oposite end of the plenum. The very poor Chilton manuel is a real disapointment. Not very detailed on much compared to the Chiltons on Monteros. I got it on interlibrary loan, it took a month to get. Not worth waiting for. I need the real manual to do a complete MPI system conversion to keep from shorting something. I probably should back off on this one.
The CA engine for the 94 is much more complicated on emissions sys than the CA 93. Looking at Alldata( the manual doesn't even show an exhaust sytem or a C. converter) it appears that there is a cat. con. on each ex. maifold with an o2 before and after the cats. I think there is another cat. after the pipes connect.
All the CA Mon. Sport 24 valves have a similar setup.
. <img src="/forums/images/graemlins/frown.gif" alt="" />
I think I'm gonna go like Justice's setup , just the heads and block from the Diamante. I can afford the high octane about as well as regular I guess.
The injectors in the Dia. have the same resistance and the diagram on the ECU wiring is no different than my 89 on the injector. They are supposed to be sequensial. The Turbo engines seem to be the ones with very low resistance.
Anyway I gotta go write a post on H.B. bolt .........

I've been running 87 Octane with no issues with putting at least 5K miles on it so far. Not to say its good to go but from my experience it works very well. The engine is very peppy on the low to mid range. My SWB laughs at 33's but I have yet to load it down with gear and heavy duty bumpers and other such stuff that will eventually slow it down some.

The '89 does have a MAP sensor.... of a sort.... it's actually not a MAP sensor since it doesn't sense "
manifold pressure - but an AP sensor incorporated in the MAF sensor as a barometric pressure sensor. All it does is sample the barometric pressure each time the engine is started and uses that value as an air density calculation in the fueling equation until you turn off the ignition. If you drove from sea level to say 10,000' in one trip, with the '89 (and many other vehicles) you would be wise to stop a few times, turn off the ignition and let the ECU reset to current conditions - that is if you wanted the best performance and economy.

Some of the '89s had high altitude sensors.... don't know if they were a one-time sample or on-the-fly correction - I suspect the latter.

The Diamante may have more MAP sensor control as in on-the-fly correction , but I'm not sure.



That should be the butterfly valve arrangement that alters the induction runner length. The ECU needs to know what position the valves are in for best performance, so that sensor is like a TPS.

If you use the Diamate engine with 10:1 heads and Diamante cams, you can probably do what Justice is doing and run 87 octane. At worst, 89 octane and a timing adjustment should be fine. The dynamic CR just isn't that much different than the stock '89 Montero arrangement. I would caution against using the Montero cams with the Diamante pistons though.... it would increase the dynamic CR to 8.3:1 as compared to 7.4:1 for the stock Montero and 7.8:1 for the Diamante pistons and cams. 8.3:1 is likely ok, but might require high test AND a distributor spark lead adjustment.... plus, the power would be lower than would benefit you. The 3.0L needs power at highway speeds (particularly with larger tires), so the Diamante 10:1 pistons and cams should be fine for a N/A engine that does very little towing.

Frank

Just notice that the short block I put in here has the two pins in the block where the AC bolts up. I hope its a Dia, may Sonata and not a Caravan.
Frank, you said the Dia hard a sronger block with ridges or something. Seem like there would be a different part or model #.

Here's a Montero block - note how smooth it is near the skirt flange just above where the oil pan is attached:


Here's a SOHC Diamante block - this picture shows what's left of the 2 pins that interfere with the Montero A/C bracket after I ground them - just grind them flush. It also shows the reinforcement just above the pins - see the raised horizontal ridge line? That's for extra stiffness:


Frank

So, I can use a 1992 SOHC Diamante engine from a boneyard in my 1990 Montero.

Ill just use the long block and bolt up everything from the montero engine-----Right ?
I guess ill have to grind those pins too
Will it get more hp with the higher compression ?
and will it run ok in the Montero ?

Yes - just be aware that the pistons are 10:1 CR and the cams are longer duration. The dynamic CR is close to the Montero, but a little higher. You may (or may not) need to run 89 octane - you also may (or may not) need to adjust the ignition timing. The cams will move the torque peak a little higher in the rpm band. You will no longer have a non-interference engine, so if you break a timing belt, you'll be replacing valves.

You will need the accessory brackets, engine mounts, timing covers, manifolds and some other odds and ends from your Montero engine.



As long as you use the Montero ECU and intake manifold, not much, but some. The important thing is that the torque peak will be raised a few hundred rpms so you have some reserve punch at highway speeds - good for larger tires.... due primarily to the later closing of the intake valves and longer duration of the Diamante cams.



I think it'll run fine, so long as you use the Diamante cams with the Diamante pistons. Ask Justice.... he has one and says it has more pep.... as it should. Charlie likes the Diamante cams in the truck engines, too. I've installed Diamante cams in my engine, but then my engine is a Heinz 57 model.

Frank