A buddy of mine has an 87 Trans Am 305 TPI, w/700-R4.

It has had some serious issues since he got it almost two years ago, and its a sad thing because its a beautiful car. Anyway, it did have a bad miss in it, and SES light that came on and when we scanned it, it blamed it on the Intake air temp sensor, well that was replaced twice.

It also ran like a DOG. So he did a full tune up, MSD cap/rotor, new plugs, wires, fuel filter, TPS sensor, fuel injector cleaner, spark coil, and oxygen sensor. He also had the fuel pump replaced because it went out and a recent tranny rebuild due to that dying.

Finally, he said screw it and took it to a shop. The diagnosed everything, traced it for 2 weeks and finally ending up replacing the whole ECM.

They did and it runs SO much better now. But it still doesn't run the way it did when he first got it. It has a slight miss at idle. So I said, hmm lets try seafoaming it because I did that on my friends Grand AM GT Quad 4 that had 150k on it, and it helped it tremendously. Unlike my friend with the Quad 4, his T/A didn't smoke nearly as much.

We also put one of those ***** cones after the elbow on the MAF sensor to get rid of the stock air box. We took it out for a test drive and he said it pulled a little stronger with the seafoam + cone filter, but it still has that slight miss at idle.

As in my sig, I have a 99 3800 V6 A4 with 3.08 rear. We've been talking smack, so we leave my house and get on 275 south, and on the long stretch before you hit Bearss, no traffic around we hit it from a 65mph roll on, he hangs with me for a short bit (maybe till 75) and I just started pulling him and at the end, I had him by a good car and a half. Needless to say, I am disappointed. I figured he'd beat me by at least a car or two.

http://www.fl-thirdgen.org/g8erb8.html

Thats the car, any ideas on what we could do at this point? If anything? I know it has around 120k on it, but my 3800 has 110k too and like I said it just walked him. How about that Gunk Motor flush? Also thinking of running seafoam through his oil.

 

How about a flow test / power balance test of the injectors?

SeaFoam cleans one thing well - your wallet. It rarely does any good for injectors, since they really don't appreciate water running through them. the rest of its contents might be O.K., but the water contained in it is not the preferred solvent for injector cleaning.

The "that slight miss at idle" should be the first hint of an injector flow problem.

 

I did not run the seafoam through the gasoline tank, so no contents of the seafoam went through the fuel injectors. The only thing he has ran through the injectors is regular supertech brand fuel injector cleaner through the gas tank every oil change.

I ran the seafoam slowly through the brake booster line like you're supposed to, I've had great results cleaning the intake system this way with it on other cars. However, it probably isn't as affective on TPI cars because it doesn't go through all of the plenum and runners.

Just talked to him, and he said he replaced all 8 injectors about a year ago.

Thanks for your help so far!

 

Even with year-old injectors, a complete power balance test can reveal problems with either the ignition or fuel control. As part of that, a cylinder leakage test must be done first to assure good mechanical condition of the engine.

 

Compression test? Thats one thing he has yet to do.

I was told that what went down on the interstate was supposed to happen regardless. 2.73+305+TPI equals absolutely no top end. My 3800 still has a little bit left to go, but I just don't think it should have been as bad as it was.

On a 1/4 dig race, it should be whoever gets the jump with the weight advantage to him. But I don't know, I just thought the LB9's were worth more than that.

 

No top end? Yeah, my 305 TPI w/ 2.77 gears will just barely eek out 140+. Even my wife's beater will do better than that by about 20 MPH.

 

If he has highway roll on power, howcome he got spanked, bad, by an A4 V6 with 3.08 gears that puts 150rwhp to the wheels?

Mid 15 second cars, both of ours I think. Friends 92 z28 lb9 is a mid-low 15 second car too. I'm sure yours isn't bone stock like this one and I'm sure its running right....his could probably do 140...might take a good 5 minutes to get there, but it could probably do it.

 

He's got something wrong. Possibly just loss of compression from wear. My car is about as stock as the day it left Van Nuys, except for a few little trim pieces. It still uses the peanut cam and has never had the heads off. Stock right down to the belts, hoses, and Goodyears.