Wierd?

[nik95gs-t]

So every once in a while when im driving out of nowhere the car just starts backfiring, surging, jerking, and basically just dies. Then when i wait ten mins and start it up it will be okay for a few then the same thing happens. There is no cel on and was wondering what this can be. I figured maybe coil pack, O2, but there is no engine light on. Any ideas? Thanks

 

[killer_eclipse]

sounds like it could be a maf problem or a ECU problem.

 

[Glacius_01]

+1 on checking the MAF

 

[Blackjet18t]

Easiest way to check a maf is unplug it and see if the vehicle runs better.

 

[BLINKY619]

have you checked your timing?

 

[blackhawkgsx]

Maybe a leak at the bov recirculation hose, mimicking a vent to atmosphere type of thing. +1 on the maf also check for megga boost leaks.

 

[And_44]

I am experiencing the same issue. I've swapped my MAF, coil, checked/cleaned plugs, replaced fuel injector seals, new fuel filter. I have a freshly rebuilt ECU that looks great. Injectors have about 15k on them there 450's.

This all started about a month ago as a slight studder at cruise, and got worse the more heat cycles the car was put through. Now I can't drive it more then 15-20minutes after it hits normal operating temp. When it hits operating temp it will start studdering and get worse fast to a misfire. I can turn off car and let it sit for a few and then drive it again for a few more minutes before it starts all over. It's diffently heat related, just having a hard time pin pointing it.

I believe now that it is a electrical problem with the ignition system either CAS, ignition module, wires, or I just have 2 bad coils.

UPDATE 8pm

Well I just replaced my plug wires and problem is still there. My thinking now is after some reading about o2 sensors and some driving is that my o2 sensor may be on the fritz.

I drove the car till problem showed up and was wondering if I put the car at WOT (which puts the ECU in open loop and ignores o2 sensor) if it will still miss/sputter. It didn't ran great like a raped ape until you went back to idle/partial throttle.

I got an o2 sensor on order now and should have it installed on Friday. Mean while going to unplug o2 sensor and run in a open loop and see if problem returns.

UPDATE 230am

I ran car with o2 sensor unplugged and couldn't get car to do it's bad thing, may of nailed it. Gonna try again in day time and hope it wasn't because of the lower temperature.

 

[nik95gs-t]

wouldnt any of those problems throw a cel?

and also it seems to get alot worse when i push in on the clutch

 

[JDog_27]

nik95gs-t and And44,
Curious...did you ever pinpoint the problem? Having same/similiar issues happening to me. Major backfiring/bucking/jerking going on to where I couldn't even drive home today (100 miles from home)...Yay for Triple A. Going to go through the rounds and checking/pulling junk to see what's going on. No CEL showed up either.

 

[And_44]

Well, I have a few problems all doing there havoc. My O2 sensor is probally dirty because it gives a pretty steady reading of .4-.5 and doesn't flutter around at an idle.

I did a boost leak test and it was bad.... Couldn't get pressure above 13psi and when air was removed from valve it would quickly drop to 5psi then slowly go down from there. So will be addressing those in the next week or two.

I've tested the ignition coil hot/cold, the TPS cold/hot, ICS cold. All passed. I've swapped the MAF, chance's of having 2 bad MAF's with similar issue is pretty slim in my book. I've swapped the coil too but same issue. The ECU board is clean and has been refurbished recently.

Today my car was starting its misfiring as I was driving to work got to work and walked in. Well good news was I got the next two days off and start training for a new position in the company on Tuesday. Bad news. I went out to car to go home and it wasn't starting. No spark. ECU I checked the other day and it was great, when I put key to ignition the light would stay on for 5sec and turn off and stock boost gauge needle goes to 0.

So I then removed the ignition module because it's been getting REALLY hot to the touch when the misfire has been happening. It failed the test and when it was cool I tested it again and it passed reinstalled the module and car started up and ran ok. Then started misfiring about 5-10min into driving and idling bad.

So long story short. The misfire I believe is from the ignition module, when it heats up it performs worse or not at all and has been getting worse and worse. The poor gas mileage, weak proformance, and weird idle I believe has to do with the leaky intake, o2 sensor, and the ignition module is probally isn't helping much either.

 

[And_44]

Wow, forgot I did some input on this thread, but yes found my problem. Turned out to be a bad voltage regulator in my Alternator. Replaced my alternator and car runs a heck alot better, no more misfire. Been 2 weeks with new alternator and haven't had one repeat, and it's been in the 80's so it's been tested in the heat.