Misfire question, please help if you can.

PATDIESEL · Post by **PATDIESEL** » December 1st, 2005, 2:19 am

Well then when you get to Jersey let us know. I don't mean check wit ha timing gun, although it would be the easiest way. I mean to acutally see that the marks align in the first place. The lines can be off and the timing gun will be wacko.

Anyway, have a good trip home.
Are you going back to school or are you finished and moving back home?
If you are leaving for good, you should try and stop by on the way. It would be a good place to stretch for a few

MX3 GSR for dummies · December 1st, 2005, 10:14 am

Not sure if this helps but I had issues like this and I changed my ECU and they went away..now I noticed you have the KL36 but....did you change the TB because the ISC is different. This may be causing your rich issues at the start and then fouling your plugs. Just an idea. My rich mixture with the KL08 ECU fouled my plugs and created some backfiring but not to the ectent that your describing though.

hgallegos915 · Post by **hgallegos915** » December 1st, 2005, 6:01 pm

hey can the idle control unit (connector underneath throttle body) cause car to missfire?

FIMotorMX-3 · Post by **FIMotorMX-3** » December 6th, 2005, 11:57 am

Man it's one problem after another. Havent' been able to log on for almost a week. Well I'm still in Savannah, leaving tomorrow, my professor screwed me on grades and I've been working with the chair and dean to resolve them. If things work out, I've graduated. I'm gone from Ga, but I'll be back, have to move out in January and my girlfriend still lives down here. As far as the car goes, I'm not sure what throttle body I have. That's a stupid response I know, but as long as the place that sold me the engine didn't screw me, I'm using the one that comes with the curveneck ze, je50 vaf and the kl36. Things I haven't mentioned, is that if it were the timing, the car would run like crap all the time and also at idle, wouldn't it? It only does the misfire under acceleration and at cruising. Something new came up though, I got a chance to run the car for about an hour to an hour and a half and the miss went away. The car was running perfect. I let the car warm up to about 100-150 on my water temp gauge before I start driving it depending on the rush I'm in but the overall engine is still pretty cold, although after driving the car for a longer period of time of driving the car at around 208 to 214 degrees, the engine's misfire disappears and runs perfect, I think eliminatiing the timing issue. I also think that probably eliminates the injector issue as well. My girlfriend's brother, remembered that when her father and I built my exhaust, we used a test pipe and eliminated the catalytic converter. Due to the serious drop in backpressure, O2 sensors are probably the culprit, although sticky throttle and tps are probably not helping. Since the o2 sensors mount in the manifold I didn't think that removing the catalytic converter would effect them that much. So going back to the original recommendation, does the car warming up completely and running fine narrow it down to possibly those o2 sensors? I admit, I know for the most part what parts deal with air/ fuel, and what parts deal with spark, etc. etc. and if you give me a bunch of tools and tell me that I need to start replacing this and that, I'll have no problem tearing into the engine, but as far as diagnosing things, I'm still learning as I go. This is my first swap. Before I basically slapped bolt ons on everything I've owned. So sorry if I'm a pain in the @rse..... I blame it on fuel injection and electronics......

PATDIESEL · Post by **PATDIESEL** » December 7th, 2005, 12:09 am

I've seen rough running from no cat cars, but is this a new engine and a new problem. From what I remember you've had the ZE for a bit and the misfire is new. I doubt O2s are the culprit, but I cannot say for sure since they play a direct role in fuel amounts.
Call me sometime if you want. PM me on MOCA or here and I'll give you the number again. it is too hard ot remember what we have been over for the past few weeks now.

FIMotorMX-3 · Post by **FIMotorMX-3** » December 8th, 2005, 11:18 am

Thanks Patrick, yeah, the engine was swapped in May, and this just started just about the time I did the exhaust, which has been about a month ago now. I'll pm you soon. I just got back up to Jersey at 3am this morning, so I'm beat and in no mood to start messing with the car. But not to my surprise she ran great for the whole 900 miles.. a little stutter and pop here and there when it missed but at cruising, no problems at all,

ran great... well, back to bed, a 12 hour drive, a few hours sleep, and unpacking a car wore me out. I also have a buddy on here that was only about a half an hour drive south of me. Buff1110, anyway, I'm thinking of driving down to check out what's new with him and his mx3 (just ordered already modded civic projectors), maybe he might have some ideas from experiencing the problem in person. He helped me with some tech stuff on my swap when I had questions.

PATDIESEL · Post by **PATDIESEL** » December 8th, 2005, 12:50 pm

Glad you made it home safe. Good luck, a second set of fresh eyes always helps. Let me know if there is anything else I can do to help.

hgallegos915 · Post by **hgallegos915** » December 8th, 2005, 5:53 pm

mine got fixed with a new disty .. first time i see a distributor behaving this way. Problem fixed and idle stable

i enjoy riding my baby once more.

FIMotorMX-3 · Post by **FIMotorMX-3** » December 9th, 2005, 12:45 am

Yeah, I'll definately keep you posted on what I find, and if I have questions. I'm hoping it's not the disty, This is my third one in the car and the second rebuild. I thought the problem was fixed when I switched out the last disty, but the car only ran good for about twenty minutes, although they've been known to start acting up almost right away. rebuild disties are crap, but they are really the only thing reasonably priced. If it turns out to be that crap, I think I'm doing the external coil, hei mod. Once the snow stops falling and I can get out there, I'll let you guys know what I find. I'm back with my tools....

FIMotorMX-3 · Post by **FIMotorMX-3** » July 17th, 2007, 10:00 pm

Well Pat, I sold the car to a really good friend of mine because I didnt' have time to work on it (some 50-70 hr work weeks at the time) and i was getting really frustrated with it. It's running like garbage now and sometimes not running at all. My buddy took it to a local shop and had the timing checked and belt inspected. They had the car for three weeks and can't figure out what's wrong with it. Wanna get it running so my buddy can throw some boost at it. I'm fowarding him any conversations I've had about the car so he can start looking at the variables and see what I've done to the car. Granted I've told him everything about it. But hopefully she'll be running again. Sooner than Later. Hope all is well down in the atl. Been to Roebling lately?

jaydog5678 · Post by **jaydog5678** » July 18th, 2007, 6:10 pm

I know this thread is old, but I'll throw in my .2 cents. Any engine that sits for awhile at an importers warehouse or lot has a high possibility of the injectors freezing/gumming up. It is very likely that one or more of the injectors is the culprit. A simple resistance test on an injector will only show you just that. You still have no way of knowing the spray pattern or if there even is a spray pattern on a bad injector when the engine is running. The injector can be difficult to diagnose because of this. When you ran the injector cleaner in the tank, that helped but the problem came back several days later. That tells me that it's more of a problem with the fuel system. Another solution to buying new injectors is to have them cleaned professionaly. It's much cheaper then buying a brand new set of 6 and usually has good results. The guys who do this can tell if the injector needs to be replaced or not. They can also see the spray pattern and can even match the flow rates to very close tolernaces. Hope this helps some.

FIMotorMX-3 · Post by **FIMotorMX-3** » July 24th, 2007, 7:25 pm

Thanks Justin. I've always suspected that to be a possibility. I really have to get a day to tear into the motor with my buddy. It's hard because for the past year I've been working 6-7 day weeks. My days off don't always coincide with his. Hope everything is well with the MOCA boys. Did you do some more work to the car? From what I could remember when I met you guys at Roebling I thought you only had 250whp? You up to 301 now? That from the GT turbo?

FIMotorMX-3 · Post by **FIMotorMX-3** » July 24th, 2007, 7:27 pm

Also, the thread may be old, but unfortunately the problem is still very current. It isn't the motor either. I've thrown out the idea of just swapping another ze instead of tossing money away at parts that may or maynot be broken but unfortunately it's an external problem and nothing to do with the engine internals from what I can gather.

PATDIESEL · Post by **PATDIESEL** » July 24th, 2007, 11:39 pm

Sorry to see that this problem is still around. I agree with Justin and he knows more than I do. Could easily be injector related. It sounds like it might be easier to take this to someone who can help with a professional set of eyes and ears. It is so hard to help diagnose over the internet that all we can do is throw ideas your way an hope you check them out properly.
It was really nice to meet you so long ago and we have been back to Roebling since. Our last trip was last year around September IIRC. Justin blew the manifold off of the turbo with all that boost from the GT28. He got it home and fixed the crazy bolts that the local tuning shop put in for him. Since then he blew the whole motor at Road Atlanta back in June while racing. Something funky happened b/c he melted the F out of one of the pistons. He is currently putting it all back together with some more bullet proof parts that should make him a tad faster and alot more reliable under the pressure he puts on the motor. All of the rest of us are doing well and just enjoyed a PDX at Road Atlanta this past weekend. In the rain, but it was fun to see how our setups did in the wet. I had fun kicking the crap out of a Z-06 (no lie or stretching the truth, I was on his rear for 2 laps and he got about 3 flags telling him to move over and let me by, hehehe).
If you and your buddy want more help lets start a new thread on here or the MOCA forum so that we can refresh the topic and the issues.

Firefly · Post by **Firefly** » August 1st, 2007, 7:53 pm

Hi all, new to forum. Have what sounds similar running problem with my '96 model. Very little tech knowledge but car has irregular popping noise when idling and very jumpy when I am accelerating gently (significantly better though when I am accelerating hard) and it is is diificult to hold at a constant speed without it jumping. I have completely standard car with 78000 miles on clock. I actually bought the car with knowledge of the fault and previous owner had new distributer cap, mass airflow meter (although it was second hand), fuel treatment, engine flush and the usual plugs, leads and filters. I have had the cam belt done and the ecu fully tested -no faults showing and ecu is fine. I have also had the compression tested and all came back at 182.
It was suggested that I try another mass airflow meter but it's rather expensive . Can anyone advise if this might solve the problem? Thanks