Chrylser/mitsu/hyundai 3ltr v6 misfire?

Been working on a Minivan with the above stated engine in it, and the damn thing has a miss fire that I cannot track down. Replaced plugs, wires, cap, rotor, water pump, timing belt, as well as a slew of other miscellaneous gaskets, (was leaking oil like a sieve, to the tune of about a quart a week, the engine bay was flat freaking NASTY!) But the darn thing is missing. I was that way when I started, I pretty darn sure it didn't move on me when I was putting the new belt on. any suggestions?

If you used engine cleaner with a power washer, you may have shorted out/grounded a sensor. Any codes coming up? Was it missing before you did the work?

Worst case, you jumped a tooth on the timing belt. Go over everything you did from a fresh pov, slowly. It might be something as simple as a loose wire to the cap/plug. Did you properly gap the plugs?

Coil?

One thing that'll get you on those is corrosion on the injector connectors. Bumping or tugging a wire on accident that jars one of those connections can make it do that.

It is possible, but difficult, to get the injector connectors on and off with the plenum still on, IF you have a.. say 92 or 93 or later van. The earlier ones used a metal clip on the injector pigtail and i would NOT mess with those without just taking the plenum off first.

Misfire was there before I started work on it.

Have not checked the coil, other than yes you get the E36 M3 zapped out of you if you remove a wire wrong with it running, ( tried the whole, pull a plug wire while running see if it runs any worse) I think the computer compensates to quickly for it. I've put a timing light on it, and it blinks steady on all the wires but one. I have tried one of the old wires, same result, pulled the plug, and got all kinds of spark out of that plug, hmmmm I wonder, if I say held the plug near the hole while it was running how big the flame would be coming out of it. not sure I want to try that one. would tell me if it's getting fuel though. Didn't check the gap on the plugs, I didn't have a gauge handy, and just went with the presets. I know I know, always gap them. I just wanted to get it running. and it's a 1999 voyager.

Engine cleaner, yes, power washer, no.

The "press both trip and reset while turning the car on" trick yielded code 23 and code 55.

Code 23: Charge air temperature sensor out of range
Code 55: End of codes

OK, so the IAT is out of range, that shouldn't be to hard to replace. Problem is, where the $%^$* is it? None of the sensors I can find that are anywhere near air look like the part pictured at the online parts shops.

Oh yeah, everything I read says I should be getting 3-4 digit codes that start with P , but none of the code charts for my model year show code 23. Now if you go to the charts for a few years older, they are all number only codes and code 23 is a possibility. Odd!

Semi related are these motors interference designs?

3.0 SOHC is a non-interference motor at least in the chryslers

( tried the whole, pull a plug wire while running see if it runs any worse) I think the computer compensates to quickly for it.

You definitely need to unplug the idle control motor on the throttle body before trying to do a power balance test. Unplugging the coolant temp sensor may also help because it stops the computer from changing timing to adjust idle.

not sure I want to try that one. would tell me if it's getting fuel though.

So would unplugging the injector. Same idea as pulling the plug wire and listening for rpm drop. As before, unplug idle motor first.

And of course, unplugging spark plug wires, injectors, idle motors, or CTS's is going to set codes on that thing, and youll have to reset them later.

3.0 SOHC is a non-interference motor at least in the chryslers

True.. to finish the unspoken, the mitsu versions had 10:1 pistons and WERE interference.

In reply to Vigo:

Do you think the code 23 is a result of our wire pulling, etc... experiments? Do you know where the IAT sensor is?

BTW-I am working on the same van as Spinout007 who started this thread. 99 Voyager

Ok after a week or so away from this thing I decided to take another crack at it. Narrowed down to a cylinder, got the injector unplugged, runs the same, now there was a tiny tiny bit of white stuff on the plug, not dielectric grease white stuff but powdery white stuff. Very small amount...now should I hit it with some crc spray for elec connections, dielectric grease or just cleant it to the best of my ability, and then plug it back in?

Absolutely

So just to be sure, did you pull that plug wire and make sure its getting spark?

Seems obvious but im just checking.

If its got spark and unplugging the injector didnt change your rpm, its definitely an issue with that injector.. either not firing because of bad connection/wiring, or not flowing because of being clogged.

MrJoshua wrote: The "press both trip and reset while turning the car on" trick yielded code 23 and code 55. Code 23: Charge air temperature sensor out of range Code 55: End of codes OK, so the IAT is out of range, that shouldn't be to hard to replace. Problem is, where the $%^$* is it? None of the sensors I can find that are anywhere near air look like the part pictured at the online parts shops. Oh yeah, everything I read says I should be getting 3-4 digit codes that start with P , but none of the code charts for my model year show code 23. Now if you go to the charts for a few years older, they are all number only codes and code 23 is a possibility. Odd!

not odd, its a 1999, and everthing sold in the us after 97 was federally required to comply to OBDII. number only codes apply to obd1, an older diagnostic system. get a scanner and plug it into the connector under the dash. if you use a generic scanner then you will see one or more codes that look like P0xxx. if you use a scanner that shows manufacturer specific codes aswell, then you will also get P1xxx codes. do that and then tell us what the scanner tells you

In reply to grimmelshanks:

I get 23 and 55 using the self diagnostic built into the car. Is that method inaccurate? I would prefer not to buy a scanner if I don't have to.