Strange missfire.. Need help :(

[Mike Neal!]

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 (http://www.mitsustyle.com/forums/#) 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

[sleepydsm]

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

[mike55112]

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

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.

[Mike Neal!]

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?? :(

[95talonracer]

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.

[mike55112]

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?? :(

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

[Mike Neal!]

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! :)

[95talonracer]

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

[Mike Neal!]

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..

[95talonracer]

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.