Hello,
I have just bought a 87 GTA and it proffesionally tuned up and it is runing great. I idles great and starts right up. I also have a 1985 Trans AM that reaches high speeds much faster than the GTA with the 350. The GTA had been stopped for about three years before I bought last month. It seems to be clogged or has very little flow. Do you think this could be the problem with the car??? Please let me know what you guys think. I would appreciate any help you guys can give.

Thanks,
Rodrigo

 

i would check how much exhaust pressure is there with a guage. otherwise do a compression check, etc to see what condition the motor is in. also are you sure it's really a 350 motor? it should have TPI then, not TBI

 

Are you talking about the exhaust here? A clogged converter or muffler can severely hurt performance. When my sister's 94 Formula clogged it wouldn't rev past 3500rpm, and lost a ton of power up until the 3500rpm limit. All I did was remove the converter and it instantly ran much better. Remove yours, or at least unbolt it, and drive it. If it runs much better, that's your problem.

 

Yes im sure its a 350 CI because I put the motor in myself. It did have a TPI unit but it was damaged beyond repair so I decided to buy a new intake, dist, and carb and I did a carb swap. I had someone check the compression on all the cylinders and was a little above 120. I had everything timed and checked and then double checked. Everything is a OK. I also put in a new 700-r4 trans. How do I check the exhaust pressure and If I do, what should it be on? Do you think the exhaust could be the problem??

 

120 PSI is pretty low. Depends on the cam but is around 8.5 to 1 CR. 10 to 1 is around 190 PSI. Low compression might be contributing to a lack of power.

 

The motor is completely stock......no new cam or anything. You think 120 is low? I thought it was pretty good.

 

For a stock engine thats just fine!

 

Damn...when I first got my hands on my car one of my cylinders was at 50 and 2 were at 60. But the damn thing still ran. Put some seafoam in the spark plug holes now they are all around 105-160. But I need a rebuild bad

 

That makes the problem 100 times more difficult to diagnose. Had it been a factory setup, we have given engine specs, so we know how it should perform.

Now we have an 350 with unknown specs, and an unknown induction setup. Given some of the 350s that were produced, its entirely possible that a 85 305TPI could be faster than that 350. We need more info.