Running rich
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Joined: Dec 2004
Posts: 62
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From: Bloomington IL.
Running rich
My 86 exhaust smells rich at idle. Additionally the cat recently failed. It is running fine since replacing tge cat. It has been modded, bigger cam, headers, runners, throttle body and a Hyperchip. All was done by a pro shop in Ca 20 years ago by the previous owner. It also has an adjustable fuel pressure regulator. If I were to back off the fuel pressure would this help at all? I am fairly handy but don't have a fuel pressure gauge. Any suggestions would be appreciated.
PS..in 2015 it had an issue where it was running rough and fouling plugs. A local shop chased their tail for quite a while. Replaced the coil, computer mass air, throttle body and intake gaskets before getting it close to back to normal. It has always seemed to running rich judging by the smell of the exhaust.
PS..in 2015 it had an issue where it was running rough and fouling plugs. A local shop chased their tail for quite a while. Replaced the coil, computer mass air, throttle body and intake gaskets before getting it close to back to normal. It has always seemed to running rich judging by the smell of the exhaust.
Team Owner
Joined: Jul 2004
Posts: 28,381
Likes: 3,262
From: Hartford WI
My 86 exhaust smells rich at idle. Additionally the cat recently failed. It is running fine since replacing tge cat. It has been modded, bigger cam, headers, runners, throttle body and a Hyperchip. All was done by a pro shop in Ca 20 years ago by the previous owner. It also has an adjustable fuel pressure regulator. If I were to back off the fuel pressure would this help at all? I am fairly handy but don't have a fuel pressure gauge. Any suggestions would be appreciated.
PS..in 2015 it had an issue where it was running rough and fouling plugs. A local shop chased their tail for quite a while. Replaced the coil, computer mass air, throttle body and intake gaskets before getting it close to back to normal. It has always seemed to running rich judging by the smell of the exhaust.
PS..in 2015 it had an issue where it was running rough and fouling plugs. A local shop chased their tail for quite a while. Replaced the coil, computer mass air, throttle body and intake gaskets before getting it close to back to normal. It has always seemed to running rich judging by the smell of the exhaust.
With the bigger cam and the HyperJunk, who knows what is happening. You might have to figure out what the cam was and get a tune done for the car and not some off shelf crap
Team Owner
Joined: Jul 2004
Posts: 28,381
Likes: 3,262
From: Hartford WI
Ask around the dyno shops. They might have the stuff to burn a custom chip for you. I'm kinda skeptical of the "Guess a Tune" people since none of them have said that they can't do a better job if it were on a dyno vs taking specs.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
You will have to search TPIS , PCMOFNC there are more in house with dyno will be limited. You will need to make logs of data to have new proms made.
it's possible that it's not the prom, since you claim mods were done years ago. You may look for someone with more experience with tpi and obd1 to help you.
it's possible that it's not the prom, since you claim mods were done years ago. You may look for someone with more experience with tpi and obd1 to help you.
