I used their cam designed for use with fuel injection. Not very radical to keep peace with the ECU.

>>>*H'lo!

I read all this thread, and this does not sound like a misfire.

My best guess since the shudder is midrange and goes away with the air conditioning engaged that there is an out of balance condition. Those tend to show up at around 2500 RPM or so, then again at around 5000 RPM when the condition isn't serious. If WAY out of balance she lets you know right away, just a few grams is tough to chase down.

Engaging the air conditioning increases belt load on front of the engine and that tends to dampen the vibration, something I have seen happen before with inline 4 cylinder engines and some inline sixes, normally following a rebuild when the weights weren't checked...*Shot in the dark but that's what my Dad said, too....:D .*EBjr

there are some possiblitys with that theory. my last motor, i wish i didnt sell, i had balanced all the rod and piston assemblys and had the clevite performance cam and that was very smooth, i could tell a major difference over any 22re.
i went with a little more cam this time ,crane 704-0014, and didnt touch the rod assemblys and it doesnt feel near as powerful as before basically with the same set up except for the full length header vs. short header.
i had gotten the lce efi/pro split duration cam before and gave it 1000 miles, but was not impressed so it came out and crane went in. i think it feels better but i still dont believe it is up to what i thought it would be, so what i am going to do is after i get back in town in 3 weeks this motor is coming out again and i am going to go through and shave my rods down like before, i took a total of 1/4 lb off 4 rods and pistons, and see if i can get back that feel i am looking for.
i getting ready to leave on a 4000 mile plus round trip in my truck so wish me luck it makes it back <img src="/forums/images/graemlins/lol.gif" alt="" />

>>>*The Toyota pieces are pretty good when it comes to being balanced, it's a force of habit around our shop to check the weights though.

Lots of these engines have had folks there ahead of us, rods get replaced, things like that.

Balancing them is extremely easy, since the engine is vertical everything opposes, so just wiegh each rod/piston assembly. I have seen cases of the crank being out of balance front to rear but that is very rare.

Of course it is impossible to truly balance a 4 banger, all we can do is compensate, it takes 5 cylinders to hit true balance.

If your engine did happen to have a heavy rod or piston mixed in, this would explain a feeling that she is "missing" that is untunable, the comment about it going away with the air conditioning engaged is one I have seen before.

An exhaust emissions reading at mid-rpm's might offer another clue, also......*EB

the misfire is very intermittent. It'll idle smooth for a bit and then miss. I'll give it partial throttle up to @1500rpm and it'll increase the misfire frequency. There is a point when the engine seems to really change the timing when cracking open the throttle and that's around 1500-2000rpm. That position is where the misfire happens most frequently. Running it at 3K or higher rpm's and I'll occasionally hear a slight miss out of the muffler but nothing near as bad as the lower rpms.

Hey gang, Been away on vacation and business. So here's the latest findings. I had the intermittent 'click' while attempting to start the engine so pulled the starter and replaced the eroded contacts. During this time, the + cable was removed from the battery so the ECU got reset. When starting it afterwards, the engine ran so smooth with absolutely no signs of a misfire until..... it got fully warmed up and then slowly, the misfires started to occur again. So... I can only assume that this is a sensor related problem. Now, of course there are no codes being thrown. Oh.. one more nugget. It seems that once the ECU gets a good dose of engine sensor input, it'll do the misfire quickly upon starting, cold or warm. Thoughts? <img src="/forums/images/graemlins/confused.gif" alt="" />

well after 4000 mile trip across the country and back that same stutter is there, I really couldn't feel it while driving it then because i was in the 3200-4000 rpm range most of the way.
the one thing i know is that i am way under powered for driving out west with a fairly good sized load on i am guessing about 1500lbs.
and with a 50+ mph head wind it was terrible, 3rd gear pinned at 3600-4000 only barely keep 50-55 mph.
how do you guys make any power in the rocky mtn area to haul anything? another problem i had run into was brakes i had a good experience of brake fad while i was there also.
i think in a couple of weeks i will be starting another build, need to lighten up the rotating assy.
but i am still going to chase this @##$%^&* stuttering problem in the mean time.

latest troubleshooting of this problem... and thoughts... Was timing the engine and found the timing inconsistent and occasional no spark. Ohmed out the ignitor and found it to be above the spec'd range of 140-180 ohms... Mine measures 230 ohms... Is this high enough to cause this problem? 2nd... My Northwest Offroad header has the O2 bung coming off of the #2 cylinder. Since the sensor sees only 1 cylinder, could that also be causing the miss?