Clueless to whats wrong....
Thread Starter
Teching In
Joined: Jul 2006
Posts: 17
Likes: 0
From: Longview, Tx. BFE PA. And sometimes MD.
Clueless to whats wrong.... I just picked up a 95 Firehawk about 2 months ago. It has been doing fine until 2 weeks ago. It ran like crap once warmed up. It would lose power, missfire, and had like a backfire, poping type noise in the exhaust. But not the normal pop these cars have. I figured optispark so I got a new one. Ran fine for a week then its started all over. Iv then replaced alot more stuff and still the same. I dont get a SES light either. Anybody have any ideas? Thanks
Heres what iv done: Optispark, cap and rotor, water pump, both the coolant and tempeture sensors, spark plugs, wires, Ignition coil, Ignition control module, T.P.S., and M.A.P. sensor. I also checked fuel pressure and its 42 with key on engine off and with the engine on its 38.5
Heres what iv done: Optispark, cap and rotor, water pump, both the coolant and tempeture sensors, spark plugs, wires, Ignition coil, Ignition control module, T.P.S., and M.A.P. sensor. I also checked fuel pressure and its 42 with key on engine off and with the engine on its 38.5
Launching!
Joined: Dec 2005
Posts: 230
Likes: 0
From: Azusa, Ca.
I can almost guarantee its the ignition control module. Very sensitive to heat. When You replace it MAKE SURE to use dialectric grease on the mounting surface. Did You use dialectric grease when You replaced it? Did You use one from the dealer?
02 sensors......causing problems after the PCM hits open loop and the 02s start taking readings......during closed loop cycle (warm-up), they are on a table with set values, so it will run normal. my .02! 
Thread Starter
Teching In
Joined: Jul 2006
Posts: 17
Likes: 0
From: Longview, Tx. BFE PA. And sometimes MD.
It starts poping as soon as i turn it on. It doesnt start missfiring until another 5 mins. Its prob around the mark after 160 between 160 and 210 whatever that would be if that makes sense?
I put a new Ignition control module when I did the opti for a second time this weekend. Its a Wells and yes I used dielectric grease.
Im starting to think it might be 02 sensors because when on the highway my SES light would turn on for a few min and the go off and someone suggested o2 sensor. But if they were bad now would it trigger the SES light?
Id hate to tear it down all over again to find out its not timing. I just wish I knew what it is so I can fix it! Thanks for the help fellas.
I put a new Ignition control module when I did the opti for a second time this weekend. Its a Wells and yes I used dielectric grease.
Im starting to think it might be 02 sensors because when on the highway my SES light would turn on for a few min and the go off and someone suggested o2 sensor. But if they were bad now would it trigger the SES light?
Id hate to tear it down all over again to find out its not timing. I just wish I knew what it is so I can fix it! Thanks for the help fellas.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
Teching In
Joined: Jul 2006
Posts: 17
Likes: 0
From: Longview, Tx. BFE PA. And sometimes MD.
So if its possibly o2 sensors is there any way of figuring out which one it maybe? The computers not throwing any codes the one time the SES light came on by the time I got to work to scan it the light went off and there were no codes. So yeah I dunno which bank isnt running right if its o2 sensors.
If all else fails I might as well get all 3 o2 sensors im sure they are all factory just like everything else iv taken off of this car so far.
If all else fails I might as well get all 3 o2 sensors im sure they are all factory just like everything else iv taken off of this car so far.
Originally Posted by Hot94Z28
I was told if you unplug your 02's it will keep it in close loop and thats one way you could trouble shoot instead of throwing any more money at it yet see if that works
If you unplug one (or both) of the O2 sensors it will not enter closed loop. If the problem goes away you know the sensors are bad.
Thread Starter
Teching In
Joined: Jul 2006
Posts: 17
Likes: 0
From: Longview, Tx. BFE PA. And sometimes MD.
Im just updating. I changed 1 of the 02 sensos and what a difference itmade. I drove it aroor 3 min and no missfires! I bought bothofthem so I might as ell change out the other one too. Thanks for the help!
TECH Apprentice
Joined: Dec 2005
Posts: 366
Likes: 0
had basically the same problem and it was my 02s...youve replaced a lot, its probably the 02s =(
Wow i didnt even read that last post you posted....lmao i knew i had the same problem! I'm just editing my post since im retarded
Wow i didnt even read that last post you posted....lmao i knew i had the same problem! I'm just editing my post since im retarded