allrighty...

well, a couple months ago... my '95 TA started having some funky misfire/detonation thing going on with the left bank of the engine(the misfire/detonation sounds like it comes from inside the drivers side manifold)....

a little more specifically... at around 1250-1500 rpms, in any gear the engine will make this "misfire" noise inside the driver's side manifold when you are accelerating... after 1500 rpms the noise stops(i'm not assuming that means it stops "misfiring", i'm just saying i can't hear it after 1500rpm)

when it does this "misfire", there is definately some torque/power loss(but the higher rpms feel fine)

the car is a 1995 Trans Am with 118k miles(there are no mods on this car that can be seen)

in an effort to fix this problem... so far i have:

installed a new Opti spark

installed new AC Delco plugs and wires(OE parts)... previously we had used NGK TR55's and some Bosch wires(a GM tech told us those parts are not good enough, but he was talking out of his *** because the Bosch wires and NGK plugs worked just as good as this OE stuff)

installed a new EGR Valve

installed new oxygen sensors

installed a new fuel filter

installed a new intake gasket(there was a leak on the old one, this definately powered up the car a little.. but had no effect on the "misfire" problem)



and that's it... the car definately runs a little better after all of these things were done... but the "misfire" problem still goes on


i've thought about replacing the coil, but i don't think that would have much effect seing that the problem only occurs on the left side of the engine... and the engine runs good in the high rpms

this issue is more of a daily driving issue... any time i'm putting around town it shows up


does anybody out there have an idea what i might be missing or what the problem could be?

thx for any help

 

9/10 times thats a plug /wire/or opti. did you route you're wires well? I'd check them. I guess you could have a clogged injector. you could narrow it down to one cyl by doing a spark plug inspection. any codes? is the car running noticeable rich / lean?

 

we were real careful about routing the plug wires... and using spacers...... this is our 2nd time in about 1000 miles to do it.....

those NGK plugs that we took out after about 1000 miles all looked very similar.... black sout on all of them, that means rich right?

we're looking into the injector next i suppose....... seems like it would stumble a lot more though if it was an injector?

i dunno... all help and suggestions are welcome and appreciated


but i guess i better inspect those wires a little better... maybe watch the engine run in the dark and check for spark....

 

I didnt like the way my car ran with the NGKs. I agree wit the GM tech there.......

I dont mean a completely clogged injector, just one that is dripping out fuel insted of spraying it out.

 

My car just starting doing this acouple days ago. Left side of the motor too. Strangest noise my car has ever made. I've been working on cars in general since I was 16(7 years ago) and when my car made this noise I didn't know what the hell to think....I'm gonna start with the plugs and work my way to more difficult parts...I'm gonna keep my eye on this thread.