94 z28 rough idle and popping out the exaust

I was driving my car and all of a sudden it starts running rough and pop out the exaust when I let off the gas, the idle is rough,I've checked for burnt wires and the plugs are good. Could an exaust leak cause this?

I was driving my car and all of a sudden it starts running rough and pop out the exaust when I let off the gas, the idle is rough,I've checked for burnt wires and the plugs are good. Could an exaust leak cause this?

yes it could. check for exhaust leak and check for a vacuum leak. one way to check for vacuum leak is to spray brake cleaner around all the hoses (lightly dont hose) and see if the idle changes...this should give you an idea of where the leak is. Good luck!

only way exhaust leak will give you problems is if it is in front of O2 sensors otherwise it wont do anything

only way exhaust leak will give you problems is if it is in front of O2 sensors otherwise it wont do anything

if he has a exhaust leak it would pop when he let off the gas...every one i have had has done that. as to the idle no exhaust would not have any effect, that's why i suggested the vacuum leak would be a good place to start.

Its runnin like its not hittin on all cylinders, so weird, it ran fine all day then starts acting like this

you have a bad optispark

Do a compression check bro. cause if your just driving and letting off the gas and it pops that means a valve is not shutting all the way. you may have some shit blocking it and not letting it seat fully.

Go buy some Z Max

Well I had a header bolt loose bout to fall out, I've checked for vaccume leaks and added zmax, still doin it I'm leaning toward the opti and that sucks lol I've never changed an opti on these cars

they are not that bad if you have the right tools and don't mind spending a sat doing it. i had my top end off in about 6hrs when i did the cam swap 2 weeks ago. should have replaced the opti then...oh well live and learn!! i don't know if you can pull the opti without pulling the balancer or not...i had to remove mine to swap the timing set so i didn't pay that much attention while doing it.

I have a sh*t ton of tools so that aint a prob do I have to drain the coolant?

I have a sh*t ton of tools so that aint a prob do I have to drain the coolant?

yes...unless you have some clamps to clamp off the hoses.

From what I've read, yes you have to drain it because the water pump has to come off. The water pump mates to the face of the block. When you remove the water pump, you expose those holes... no way to get around draining the coolant.
from z28.com
http://www.z28.com/forum/articles/47479-optispark-installation-guide.html

yes you will have coolant come from the pump to block, and since you are replacing the opti you dont have to worry about it getting wet...so if you clamp off the hoses you will only have to replace what coolant you loose. this is assuming that your coolant dosent need to be changed! if you have not changed it in a while you will need to drain all the coolant.

Sounds like a big pita damn imma check everything again make sure before I get into that mess!!

before you do that, do you have a check engine light on? there are more things than just the opti that can cause the popping. if the car is not getting enough gas I believe it will do the same thing.

It comes on sometimes but its only running the ac code cuz I deleted it

It comes on sometimes but its only running the ac code cuz I deleted it
Ur best bet would be to take it to somewhere like autozone and have them scan it and see what codes ur throwing.

now is it the popping like backfiring really loud like POW?

bc i had the same problem a while back and it was my opti but it could be something else so id scan it first to get an idea of what it might be.

and if it is the opti this will help u with the unistall and reinstall.

http://www.lt1engine.com/tech/93-97-camaro-firebird-opti-remove-replace/

but like i said it could be other things doing it so get it scanned first.

Running rough and popping out the exhaust without a DTC sounds like a misfire, Could be high voltage (not monitored by PCM) or mechanical. Not ruling out the opti, but I would make sure ICM and coil test out OK prior to jumping into the opti. You checked plug wires, did you ckeck coil to opti wire, it tends to corrode at the coil end. If coil or ICM is bad they will sometimes fail the local parts store testing but not always, but you should at least get them tested before dropping a $200+ and a few hrs work into an opti. Also make sure the opti harness is not corroded or messed up..

Well I found out the longer I drive it it gets worse and the popping is more frequent, I'm going to get the coil and icm tested, I do have a spare opti I bought from laux awhile ago too

hmmm, if it gets worse the longer you drive it that may be because of heat soak. ICM's are notorious for doing that, so get that tested first!

im telling you its a bad optispark i know them all to well dont waste your time on other shit and what other ppl say just put in a new opti and get it done already no offence to anyone else ...

sorry DON-NOS, thats really a dumb statement to make. telling him not to listen to what other people say. There is more to these cars than the opti spark. I dont know about you, but I wouldnt wanna be the jerk who has never seen or heard this guys car run, tell him to replace the opti and have that not be it. it very well could be the opti, but its a better idea to rule out the easy/cheap stuff first before going straight to the opti. if you are going to give advice, think about what you say first. some of us could have the problem pin pointed in an afternoon, if we were there with the car, but we're not, so we gotta help him figure it out, not just have him start throwing parts at it.

It very well could be the opti but you gotta inspect the ignition system before you jump to a conclusion and that's what I'm doin I'm not rich I don't have money to throw around

Well I fixed it, I had the ICM tested and it was bad so I bought a duralast and she is back in biz thanks guys for the help!!

awesome man! glad you didnt just jump in and do the opti!

Well I fixed it, I had the ICM tested and it was bad so I bought a duralast and she is back in biz thanks guys for the help!!

How'd you test the ICM. I might as well do it while I have the coil out and since I'm putting in a blaster coil.

I took it to o'rielly auto parts and had them do it cuz napa,auto zone or advance auto couldn't do it cuz they didn't have the adapter so I drove 20 mins out of my way

Latest update it misfiring the dame way again so back to square one f***k!!

Did you put the grease on it?

Naw it didn't come with grease I didn't think it would hurt it cuz its mounted on a plate separates it from the block

That plate is a cooling fin. Without thermo paste, the icm can't transfer the heat to the cooling fin. (think heat sync on a pc processor). Your icm isn't getting the cooling power that it should without using the paste.

So I fried it again huh lol its a lifetimer so ill get another one