I have a newly broken in 350 tpi bored .030 over in my '90 Trans Am GTA. The tranny (700r4 w/ shift kit) was also rebuilt 900 miles ago. (Also has 2500rpm stall converter.)

Here's the problem(s). The car just doesn't feel right at all on the highway. Even with it's stock 3.23 gears. There's times where it'll actually drop rpms when nailing the gas down, then pick back up. It just doesn't feel up to par where it should be shining. Low end, around town in first and second gear the car can be an animal at times at around 3000rpms.

I was told the injectors were killing the motor. (They need to be replaced.) Also I suspect the TPS is no good. The reason for this is fairly high idle and stumbling when barely touching the gas from a dead stop. It also stalls out sometimes when going in reverse. The throttle cable feels like it has too much slack in it...but I can't be sure. (As far as the response issue.)

Has anyone had problems with injectors and/or tps that made this car/motor feel as if it just isn't what it's suppose to be? Could there be other problems I need to be worrying about? And why the hell did it take me way too long to pull a newer eclipse GT on the highway?

Thanks

 

well...what kind of injectors are you running? since you bored the engine out you should bump up to higher pressure injectors such as 24lbs. as opposed to your stock 19lbs. also you should get a fuel pressure regulator with the gauge, that way you can bump up some pressure and see if that helps, but i think the injectors mught be ur problem, but try the adjustable fule pressure regulator first i believe it only costs about $20...good luck!

 

I was under the impression that the tpi 350 came stock with either 21lb or 22lb injectors. Wasn't the 305 19lb?

Either way I was going to go with a 24lb injector. I'm mainly worried about how the car will kickdown and then all of a sudden drop rpms with the pedal to the floor. I can even feel a pretty decent size flat spot around town.

 

Sounds like u need to go over everything from top to bottom first and actually verify what parts are bad and which ones are good.

Throwing parts at a car never fixes anything unless u get lucky.

Lots of good info here and we can help you out as u test things.

U can check the injectors for leak down with a fuel pressure guage and some vise grips, can also ohm them to see about the electrical side.

Also do the same with a TPS, although a silly scope or something with graphing makes it a little easier to catch of there is a minute bad spot.

The things u listed could very well being causing the issues u have, but is the motor a stock rebuild or does it have a cam, etc?

later
Jeremy

 

It's all stock mainly from what I understand. Balanced rotating assembly, heads are "supposedly" ported and polished. To tell you the truth, I'm really not 100% sure on the head work.

I do know for a fact there is a bad injector.