SC making boost in nuetral...car accelerating on it's own new tranny slipping!!!

Not saying this is you problem but my trans went out and started by slipping then went to weak 2nd gear then first gear was not fully engaging. I would say if your gear is not fully engaging that would cause boost in nuetral it could think its in 4th and just not fully engaging just a little food for thought.
 
Mike I used some sandpaper from and old car painting project so it was a light grit. Just enough to get that burnt oil off and I used Black ultra on the plenum and blower.
 
Where did the oil come from ? It's normal to get some oil into the supercharger inlet plenum from the PCV valve hose, but adding an oil separator will address that problem.

The plenum not being sealed would cause a vacuum leak, but I've never seen a vacuum leak cause the car to accelerate as much as you were describing. Normally a big vacuum leak would make it nearly impossible to keep the car running at an idle and require constant throttle input, but would feel pretty good under acceleration. Throttle hanging up is not something that makes any sense. I would check for a binding throttle cable or cruise control cable.

David
 
The plenum not being sealed would cause a vacuum leak, but I've never seen a vacuum leak cause the car to accelerate as much as you were describing.

I agree that this might not be the full solution, but that was the location I was figuring there was a leak as it is easy to not get that tightened down flat because of the use of only 3 bolts and the offset weight that has. I believe that for sure that leak is responsible for the random signs of boost with only light or no throttle. My guess is there could be other leaks, in particular at the SC top, or the lower intercooler line to intercooler connection.
 
I had my engine smoked about a mth ago.

Discovered 3 leaks including CA Plenum.

Car idle was choppy and boost was a bust.

Interesting side effect.

Car on occasion would go done the street at 25 mph.

My foot wasn't on the gas.

This is a 5 speed.

My uneducated guess was the computer continued to hunt for intact air consistency and kept trying to correct.

Hence the drive on the fly moments.

Paul
 
I agree!! Small issue big problem!! 1FSTBRD did you get everything on the car? How does it feel?:D

I've put the DIC on and the IC tubes seem like they're way cooler, just by the fact that I can leave my hand on them after the car is at full operating temps. Definitely feels like the car pulls harder in the upper RPM's! Haven't put the supercharger on, nor the MAF/ TB, because i'm probably going to do that next year when I buy 36 lb injectors and port/ polish the lower manifold while I have things apart.
 
Got everything back on except the SC belt. But I started the car and the symptoms are the same. I will get the belt on tonight with help from a friend as last time we needed to rotate the pulley to get it on. I have a feeling nothing has changed. Mike has a tps sensor that he will be bringing on sat. I don't get it.
 
Got everything back on except the SC belt. But I started the car and the symptoms are the same. I will get the belt on tonight with help from a friend as last time we needed to rotate the pulley to get it on. I have a feeling nothing has changed. Mike has a tps sensor that he will be bringing on sat. I don't get it.

Obviously, as Mike said, the engine runs on air and fuel, not on magic. So the engine is getting air from somewhere. Either it's getting past the throttle plate, past the IAC, or sneaking in from one of the manifold or hose connections.

You said you checked the vacuum lines? Did you actually try the smoke test? I think that would be a productive use of your time.

You said you "pulled the IAC". I assume you mean that you unplugged it? If so, I wouldn't expect that to make a change. The car is already getting more air than it needs. The IAC probably is pegged at minimum already because the car knows it should do everything it can to stop the excess air.

Did you physically remove the IAC and check it for a torn bellows?

Did you check the throttle body and make sure the blade is closing properly, not bent?

There are other things to check in the future, and I suspect that one or more of them may need to be fine tuned before the car runs perfect, but the items above are the most basic and must be addressed before moving on.
 
IAC was checked and swapped out with another and there was no change. Check TB and everything is in order. Car was smoke tested and there was no leaks. Cruise cable has been disconnected.
 
IAC was checked and swapped out with another and there was no change. Check TB and everything is in order. Car was smoke tested and there was no leaks. Cruise cable has been disconnected.

Ok, thanks for clarifying.

This is a 1994, rght? If so, here's another thought - the brake booster. Maybe try disconnecting the brake booster vacuum hose and plugging it, then see what it does.
 
Haven't removed and reinstalled manifold. The ic tubes were removed and resealed with ultra black rtv. If nothing changes i will have to get the silver car running. I just didnt want to put miles on it and it looks like it needs a new fuel pump. More money and i am still not out of hot water financially yet. Lots of stress around here! !
 
I have a stock fuel pump and assembly almost new only a trip from Michigan to Kentucky and back way under 1000 miles. $30 plus shipping
 
I don't know what else there is to advise. With the smoke test and the re-checking of hoses, lines, connections, etc, it almost seems like the ECU is damaged......is it a possibility that a couple of wires had got shorted out and possibly damaged the ECU? There's so many issues here that seem to go beyond any rational explanation anymore.
 
I don't know what else there is to advise. With the smoke test and the re-checking of hoses, lines, connections, etc, it almost seems like the ECU is damaged......is it a possibility that a couple of wires had got shorted out and possibly damaged the ECU? There's so many issues here that seem to go beyond any rational explanation anymore.

Even a fried ECU can't make the car rev up without air. And it can't open the throttle by itself, especially if the cruise control is disconnected.

Another thought of a vacuum leak possibility: heater control vacuum hoses (if the 1994 still has those).
 
Will check the heater hose. Could something have been damaged when the tranny was installed? Pulled the brake vacuum line and there was no change. When I sprayed the maf looking for leaks it ran better but would still rev on it own regardless. Still running the same!!
 
Problem solved! !!! Mike can over to my house today and we checked things out looking for a way to get it running right. No luck and I had a stock TB from a old 89 and we decided to swap it out and the problem was solved. Car ran they way it should. Looks like i need a new maf sensor and the tranny shifts fine but on the highway if you kick it down it feels like OD is slipping but I guess there is no OD the way alan set it up but that can be solved in the future. I have wheels and can get to all my lessons without making my schedule around sharing my wifes car. She is happy!!!!!

A big thanks to Mike Puckett for his help and his friendship!!!
 
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