Strange missfire.. Need help :(
 

So within the last few days my car has started to have this strange miss fire.. This is how it happens.

I will accelerate normal or hard(getting into boost) 1st gear it seems fine.. 2nd gear seems fine. when I shift into 3rd gear and the rpms get to 4k it gets a viloent missfire and wont accelerate. I shift in to 4th and no miss untill about 3-3500 then it comes back. I shift into 5th and the same thing. But as I drive down the freeway when it misses I put the clutch In untill it idles down to just under 2k rpm and release it and then the miss will be gone for a lil but untill I try to accelerate. Also it sometimes just happens while not even accelerating.

The only think I could think that made it sound like its missing like that is.. I just installed a large FMIC and the IC pipe blew off and with that off it made the same sound of a missfire. But I have since fixxed the problem of the IC pipe blowing off and its been fine for a week or so.

Car:

1995 gsx w/6bolt swap. t-25. FMIC full exhausthttp://images.intellitxt.com/ast/adTypes/2.gif 98ecu so pretty much stock. I am still new to DSM's and am not sure where to begin to fix the problem. (I just put new plugs in today NGK bpr7es)

Any help would be GREAT!!!!


Thanks,

Mike

Re: Strange missfire.. Need help :(
 

Hmm, do you need to swap plug wires for a 98 ecu with a 6 bolt motor?

Re: Strange missfire.. Need help :(
 

Kevin, this is the car that blageo traded for that jimmy. It ran fine when it was sold to him. Maybe it has a boost leak.

Re: Strange missfire.. Need help :(
 

Altho I dont think it matters at all about when I got the car... It did run fine when I got it.. It also has run fine after I put the FMIC on it too.. But I dont think a boost leak would cause this even if it did (which it may) have a boost leak.. In 5th gear I will accelerate a little bit, then It will missfire like its on a 2 step.. I press the clutch in and let the RPM's drop below 2k. (if i dont let it drop below that it wont go away) If dropped below 2k and then let the clutch back out the missfire is gone until I try to accelerate again.

Not sure what that could be?? :(

Re: Strange missfire.. Need help :(
 

Is the check engine light on? If so I have had this problem with doing a 6 bolt swap with no aftermarket tuning like dsmLink. I am guessing random misfire code and if you reset the battery it will go away until the CEL (check engine light) comes back on.

Re: Strange missfire.. Need help :(
 

I know it doesnt matter when you got it, I was just telling sleepy that the 6bolt swap was done properly, so the plug wires were installed correctly for the swap. I have heard of misfires happening with the 6bolt swap in a 2g multiple times, get dsm link v3

Re: Strange missfire.. Need help :(
 

I went through a bunch of stuff, tightened hose clamps and cleaned the MAF and now the miss is gone! I should have tried one thing at a time so I know what it was.. but the miss doesnt happen so I am happy again! :)

Re: Strange missfire.. Need help :(
 

You didnt answer my question. Is/was there a check engine light on?

Re: Strange missfire.. Need help :(
 

sorry, Yeah there is a check engine light on.. code does say random missfire. But it has always said that and still runs fine. the miss that was happeneing was something other than that.. DSMlink would be nice but I have a 98 ecu in my 95 :( I would like to go with an AEM or Big Stuff 3 and get rid of that stupid MAF..

Re: Strange missfire.. Need help :(
 

unplug the battery and hook it back up. the misfire and check engine light will both hp away and once the light comes back so will the studder. do you have a black top cam angle sensor? if not get one and it will make the light stay off for longer. you can get an eprom and a burnt chip ($300 or so) and that will get rid of your problem for the cheapest and you can get dsmlink down the road.

Re: Strange missfire.. Need help :(
 

Yeah mine had the same problem... seemed to happen less during the winter for me .. but since getting the ECM/DSM_LINK I've had no more problems! :)


http://www.youtube.com/watch?v=Q6nhaT-wRxw&hd=1

Re: Strange missfire.. Need help :(
 

^^^^ yeah thats the same thing..
--------------

Talon-
I am pretty sure it was my MAF being dirty..(K&N near open hole in fenderwell with no inner fenderwell cover its exposed to weather like rain and dirt) not a boost leak.. as it doesnt need to be under boost to happen. It had a boost leak before that I could feel coming out of the pipe.. it didnt cause a miss.. it blew off a couple times and then I fixed it so it wouldnt come off and had held boost just fine.

Re: Strange missfire.. Need help :(
 

I really don't think it was the MAF being dirty, so until you get DSM link it will continue to happen on and off... Its a problem with the ECU & CAS reading a misfire & the only way to clear the code is to disconnect the battery for 30 sec or more to reset the ecu. Drove me nuts... once the DSM link was put in I've had 0 problems..

It's a 6 bolt swap correct? If so then it's what I said....

Re: Strange missfire.. Need help :(
 

^ :score010:
My 6 bolt misfire problem went away with dsmlink. Didn't happen once before the 6 bolt swap, or once after dsmlink ignored that code.

Re: Strange missfire.. Need help :(
 

I am having this probem right now, but i have a 1g with a 6 bolt and an eprom. Its pretty much the same as the description and the video. Im suppose to hit the dyno tomorrow at 2, so i need to scramble and get it fixed ASAP. Any suggestions? Im going to give the main sensor harnesses a good look through in the morning and tighten all IC piping.

It feels very similar to an IC pipe blowing off when it happens or a good boost leak, but the fact that it happens randomly leads me to believe its a sensor. Also, i have NOT had any check engine lights, so...

Re: Strange missfire.. Need help :(
 

Almost sounds like an injector going bad, coil inside is opening causing the injector not to fire.

Ive had this happen to me before, the injector would get warm and the injector coil would open, and the injector would no longer fire, causing sputtering. Maybe something to check if you have any suspicion of them, maybe your using older injectors.

It would definitely feel random. Ever get it to do it at idle?

Re: Strange missfire.. Need help :(
 

My injectors are about two years old, there 1000cc Precisions, and they cant have more than 3k on them. I dont think ive ever felt it at idle. Any way to test for this??

Re: Strange missfire.. Need help :(
 

It happened to me with stock 450cc injectors. Finally got it hot enough it was still dong it at idle. I knew I had spark, tested for power at the injectors, found good power. Then I pulled each injector clip while it was running to pinpoint the culprit. It probably isnt your case though, but you never know.

Re: Strange missfire.. Need help :(
 

Could this random sputter be caused by the 2g mas going out?