my freind recently got a 87 iroc 5.7 tpi with a junk trans the guy he got it from gave him a turbo 350 trans to swap in after swapping it the car will start and run but falls flat on it's face with throttle also the exhuast is coming out very hot it turned the muffler red hot after less than ten minutes of running thinking it may be a plugged cat but it ran fine before the trans swap also thinking maybe something could have accidently came unkooked during the installation any thought would be appreciated i noticed searching the forums a few other similar threads with no responses so if any one out there can help or has any ideas that would be great thanks

Hey man, i am having the same prob with my 91 350 tpi. It runs fine when it is cold but then after warmup and only under acceleration it chokes and falls on its face. My car was driven hot though about six months ago. Well, with a loose radiator cap. Now , it runs normal until you accelerate. Mine runs at 160 degrees, no smoke, clean oil, full radiator and resevoir. The only sign that i got after driving it hot was the car falling on it's face under acceleration. This could be a coincidence though. I did find a cracked and slightly burnt spark plug wire which i did not replace yet. Do you have any codes? My advice would be this: Check for codes, check for vacum leaks, check fuel pressure. What do your plugs look like? You really should get a COMPRESSION TEST first though. That would rule out any mechanical condition. If compression is good then i would look at your dist. cap , wires too.Let me know how it goes, I am trying to get to a solution on mine too.

ninty-one i heard about the ignition module on top of the distributor going bad after being exposed to heat and causing a similar problem from one of my buddy's if you hadn't already done that i would recomend it it didn't work for us but it could for you

well we changed the ignition module on top of the distributor and it didn't change anything today i actually rode in the car to the gas station for a test drive to get some fresh gas in it after we changed the module and when we got to the gas station (3-4miles) it wasn't running well at all and died once once it gets warmed up within a few minutes of starting it just won't run well and will backfire pretty bad it wants to die under throttle also the exhuast is still hot by the time we got back the exhuast was glowing red all the way up to the manifolds the ses is on but we don't have a scanner to get the codes and the car currently isn't plated or even titled yet for that matter im thinking it's an electrical problem but im not a mechanic my 2 91 camaros are both lo3's and haven't had any problems (knock on wood)

use a paper clip in the A & B to get the car to flash u the codes

im sorry i don't know what a and b is and where the codes will flash from can you explain more please

http://www.gmtuners.com/OBD1_DTC.htm Ok, check out that link. Those are all of the trouble codes once you find out which ones your engine light is flashing. Now just look down by your brake pedal ,under your dash. You will find a small black box with 12 small female terminals on it. http://www.obd2allinone.com/sc/toplevel.asp?cat=2 Now, check out that link. Scroll down about half way down the page and there is a picture of your diagnostic port. Now look below the picture and it shows the lettering of each hole in your diagnostic test port. Get a paperclip and shape it into a U. Now just insert one end in B terminal and the other end in A terminal. Make sure the car is not running! Now, turn your key on , but don't start your car. Pay attention to your check engine light. It should flash once, then pause. After that it should flash two more times very quickly. That signifies a 12! It will do this pattern three times and after that it will start flashing any trouble codes. Example: Flashes once, then pause. Then, three quick flashes....= code 13. Trust me, this method is just like using a regular code scanner. The male plug on the code scanner has two pins that insert into A and B terminals in your diagnostic port. LOL Let me know if you have any trouble with it.

Dude, do check those catalytics out. Do you smell rotten eggs? Also look for any discoloration of the metal on the bottom of the cats.

sounds like an est (electronic spark timing) problem. so check your knock sensor. it may be unplugged and throw a code 42 or something, and if its bad and still plugged in, it should throw a code 43 i think. your ecm sounds like it isnt telling your esc module to retard timing as cumbustion characteristics are changing.

plus that is something that can easily get unplugged in your process of R&R the tranny. its located on the side of the engine block. especially common if you had pulled the starter by any chance. a cat wont suddenly change after a tranny swap, at least highly unlikely. plus a clogged cat would cause those drivability problems when its cold too. so id rule that one out

okay update well know we got a crazy knock goin on so im gonna assume the problem was either an unplugged knocksensor during the tranny swap or just bad in combintation of a couple bad injectors that tested low on ohms so my freind has a rebuild on his hands which is good for me anyway now i got sometime get my 91 rs tbi305 5speed in shape to keep up lol