Problems with my 91 GTZ

[91_Red_GTZ]

Ok, so recently I have been noticing some problems with my 3.1/3t40. When ever my car is running, the RPMs fluctuate, and they drop even more when I turn electrical things on, eg. wipers, radio, lights, etc. Also having it in gear makes it drop down like it is trying to stall and I am running around 500-750 RPMs. I am thinking that it is the alternator, but I noticed that I had some broken wires. I fixed all the wires that I could find but still had no luck on fixing the problem. At first I thought it was the torque convertor trying to lock up, but to my suprise it was already unplugged. Also, when I accelerate, as soon as I get past about 2k RPMs, the car stops accelerating and pretty much falls on its face and bogs out. In order to get it going again, I have to let off the accelerator and let it go back under 2k RPMs and after that it seems to work fine. There is also a leak on the rear passenger side. When it rains, the floor on the rear passenger side gets soaked. The front seat and rear seat are dry, its just the floor that gets wet. I recently had a windshield installed and I thought that that would be the problem, but the front should be wet too.

If anyone has any idea what could be causing the problem, please tell me. Any help would be greatly appreciated.
Thanks

[3X00-Modified]

O2 sensor, TPS Sensor, Bad alternator... could be any of those things. What does the car do if you just try to rev it?

[91_Red_GTZ]

It hesitates then takes off. I am also getting very bad MPG and it smells like it is running real rich. I was thinking that it could be the injectors, or a bad plug/plugwire. I also thought it could be the transmission slipping because it doesn't take off like it should, but I think thats pretty much ruled out now.

[heavywoody]

Sounds like an O2 sensor to me... I'd start there.

[beroutofjtown]

ok mines doing the same thing but one difference... when i get to real high rpm (4000+) it starts to spit like crazy like all my power is gone and when i shift it goes back to normal

[91_Red_GTZ]

Mine does it that high sometimes. It will only shift once I let off and slowly go back into it or if I red line it... and thats not very healthy lol.

[3X00-Modified]

time to service some O2 sensors.

[beroutofjtown]

so if u guys r saying that i am going to replace them how many are there i know of the one on the manifold on the back side of the motor is that the only one

[91_Red_GTZ]

What about the leak inside the car? Anyone know where the water could be coming from? Its getting pretty bad since it has been raining alot more lately. Any suggestions on drying it all the way up so that it does not get worse?

[heavywoody]

On both your cars, there is only 1 O2 sensor, located in the rear manifold. 96 guys are the only ones with 2.

For the leak, there are three places to inspect.

1. Door seal
2. Quarter window seal
3. Rear window seal

[91_Red_GTZ]

Ok I'll check those places out, thanks. I noticed that I had what sounded like an exhaust leak up near the manifold. I was told that its normal and all berettas sound like that. Could that be part of the problem? Also, what are your opinions on straight piping the exhaust?

[heavywoody]

No exhaust leak is normal. Could be the gasket mating the manifold to the head, or an EGR gasket that's bad, or rusted out parts. A leak won't cause you problems like what you've described.

Straight piping is a personal preference. It's not going to gain you much power, but it's going to be obnoxiously loud.

[91_Red_GTZ]

Well, there is a fair amount of rust on the underside of the car. And for the water leak, wouldnt anything else be wet if it was caused by a leak in the door or window? like the seats? I was thinking that there could be a small rust hole in the floor board and water could come inside whenever I am driving through wet conditions. But, the floorboard is very solid so I don't know. Ill still check the windows and doors.

[heavywoody]

Depends on where the leak is at... if it's small enough, the seats won't get wet.

There is a "drain plug" of sorts under the carpet/padding on the rear footwells (one on each side). The seal for the plug could have deteriorated, but water wouldn't normally get in that way since it would have to travel up.

[3X00-Modified]

I'm willing to bet your leak is the firewall leak that they all have and its just leaking so bad its ending up in the back seat area too. Mine does it and that's why it never sees rain till I can properly fix it

Red car may have a pond in it since I haven't driven that car in a while... LOL