Ok. I know that I already know the answer to this, but I have to be sure. I was driving my car today and was getting on it a little bit around town. When I got home and parked in the garage I happened to notice something on my polished tailpipe(3" Mac catback w/ 3" flowpath H-pipe and 1 3/4' primary full length headers btw). When I went to wipe it off I noticed that my tailpipes were very warm, almost too hot to touch at first! This makes me wonder if my car is running lean? My fuel pressure gauge is reading 42psi at an idle and my Air/Fuel ratio gauge reads that I'm in the safe zone(stoich) while driving and getting on it hard(not that I really trust it tho). It also seems tho that my exhaust is very fuel heavy as it will choke you out of the garage(with the door open)after only a couple of minutes. My car has had an intermittant cut out problem lately that only happens at high rpms after I shift and this has got me wondering. Any feedback would be appreciated.
You could always remove the spark plugs and check the color. If they have a powdery white color then the car is lean, a good lean (if they are white and blistered then the car is dangerously lean), if the plugs are black, the engine is rich. You can also remove the O2 sensors and check the color to check for rich/lean conditions.
Or you could run a 10-min. KOEO/KOER self tests combo and check what the EEC has logged in terms of any A/F related failure codes + perform a real-time check of the system (engine running).
At least if you run the KOER it will tell you if 1 bank is lean or both. If both you know you have a problem not related to just one side. The EEC-IV will tell you straight up Lean or Rich. Here's 3 easy codes to help...
136 - HEGO sensor circuit indicates system lean (left side)
137 - HEGO sensor circuit indicates system rich (left side)
141 - HEGO sensor circuit indicates system lean (both sides)
I had the same issue, guy I bought the 88 off of had SD setup had too many mods on her and the SD ECU couldn't adjust.... Was great for E-Tests though... Cause she ran so lean there was no hydrocarbons
I have the same exhaust you do on an 85 GT carb tho my tips used to look clean there like a blackish inside i smell heavy gas/exhaust fumes too...I have an A/F gauge also and a Fuel pressure gauge all read fine i pulled hte plugs they looked perfect...i dont know...Im changing my mufflers out soon dont think thats going to have anything to do with this but i just dont like the sound of Mac mufflers....On your breaking up part did you check the cap/rotor...maybe wires might be to close to the headers....How is the coil?
well, I haven't got a chance to check anything else out yet, but was gonna say my other issue is not really a break up/cut out issue. Sometimes after I make shift(while getting on it hard) the car just looses all power like the fuel pump shuts down the instant I let the clutch back up from the shift. It doesn't stall out just kinda does nothing. It will do this as long as I keep the throttle pedal down. As soon as I let up off the pedal it comes right back instantly as if it never happened. Crazy?!! I'll check the other sfuff out related to my exhaust pipe question and get back with ya guys. Thanks for the input so far!