Help...Car runs like total chit!!

[TrueBlue95GT]

I put my new heads on about a month ago, and the car was fast as all hell. I was keeping up with my friend's supercharged 99GT. Then all of a sudden I noticed the car was becoming slower. Now it's gotten to the point where I can't even make it up hills. I've got an air/fuel gauge and whenever I go more than 1/4 throttle the car loses all power and the gauge goes totally rich. Also, the car bucks, pings, misfires, and I can hear a hissing coming from the right side of the motor. The vacuum gauge looks really low and at quarter throttle the vacuum is almost at 0 in of mercury. It kind of sounds like a vacuum leak, but I can't find one and it just appeared out of nowhere. Help!!!!

 

[final5-0]

Sounds like (no pun intended) you know what the prob is but don't know exactly where it is. Just track down the noise and fix the prob. Wiggle all the hoses around and it might help you find it.

Good luck!

Later
Grady

 

[brentwoodboy]

Spray some starter fluid around where the hiss might be or some other petroleum based thing and if the engine revs you found your problem.

 

[TrueBlue95GT]

What I'm really thinking is that my throttlebody is leaking. I'm not too sure about it though. How can I go about checking it? If it were leaking, I think it would be leaking from where the throttle shaft goes through the housing on the bottom.

 

[TrueBlue95GT]

I tried spraying starter fluid around the passenger side of the car, but no increase in rpms. It really sounds like I have a leak near the oil pan or somewhere down there. I tried eliminating the vacuum hoses going from the bottom of the manifold to the lower manifold and the hose going from the valve cover to the inlet pipe. Didn't help a bit. I'm out of ideas. I'm starting to think it's a blown head gasket.

 

[DJHA90]

Make sure your pcv valve hasnt popped out.

 

[TrueBlue95GT]

It keeps on popping out, but when I put it back in, the ride quality doesn't get any better. I'm out of ideas. Does anybody have anymore?

 

[Tayohs 95Gt]

I put my new heads on about a month ago, and the car was fast as all hell. I was keeping up with my friend's supercharged 99GT. Then all of a sudden I noticed the car was becoming slower. Now it's gotten to the point where I can't even make it up hills. I've got an air/fuel gauge and whenever I go more than 1/4 throttle the car loses all power and the gauge goes totally rich. Also, the car bucks, pings, misfires, and I can hear a hissing coming from the right side of the motor. The vacuum gauge looks really low and at quarter throttle the vacuum is almost at 0 in of mercury. It kind of sounds like a vacuum leak, but I can't find one and it just appeared out of nowhere. Help!!!!

im having the same exact problem.. cept min e sometimes doesnt fire on all cylinders and sometimes it does.. but i have prettymuch the exact ***** i have the hissing the ping the missfire. ect.. so yeah hopefully we can kill 2birds w/ 1 stone on this one..

 

[TrueBlue95GT]

Well at least I know I'm not crazy...

 

[Tayohs 95Gt]

anyonke have an idea???

 

[stang_dan]

ok i got a couple of idea without seeing it
1-check all spark plugs make sure they are not falling out
2 look around headers for any of the vaccum line that could of gotten melted and a hole if now there
3 there is a vaccum block on the fire wall i think like 6 thing go to it check that whole are out if a line is missing plug it and see if it runs better
4-CHECK THE VACCUM LINES THAT RUN TO THE FUEL REGULATOR AND WHEREVER THEY GO IF THAT LINE IS MESSED UP THAT COULD POTENTALY MESS WITH YOU FUEL.
5- check spark plug wire to see if they melted to the headers lol.
6-also check the big vaccum line that runs to your brake booster

im out of ideas let me know
dan

 

[TrueBlue95GT]

I eliminated the vacuum tree, the line to my fpr is fine, the brake booster line is fine, the spark plugs look fine, even if the spark plug wires were burnt, which they arent, I wouldnt get low vacuum. Could a blown head gasket make these symptoms? I've got about 14 inches of vacuum at idle, whenever it seems like theres a load, the car runs super rich, I have missing, pinging, and a hissing noise that gets louder as the throttle opens more. I literally can't get up hills without downshifting into 1st gear and it starts bucking really bad. Please help me get the car to run better until I put my 347 in!!!!

 

[haulbalz]

Check your timing, that's something that if not tightened all the way down could get progressivley worse. happened to me....

 

[AznStanger3v]

im not too sure its your headgasket. a blown headgasket on a vacuum guage makes the needle float over a wide range. low, but steady vacuum is usually a sign of a big leak, like an intake manifold. and the idle vacuum should be around 20 or so "Hg

 

[TrueBlue95GT]

Ok, so today I changed the lower intake manifold gasket and the problem still exists. I even put aviation gasket maker on the gaskets to help them seal. I am beyond mad right now. I've only got two other possible ideas. Since I installed the trick flow valve covers when I swapped my heads, I had to make a vacuum/oil fill pipe and I made it on the drivers side vc. I used an AN elbow and put a hose to the air inlet. I'm thinking that the AN fitting is too tall and its not letting the upper seal. The other idea which is kind of a long shot is that I need to redo the roller rockers. Any help with my ideas would be appreciated.

 

[final5-0]

Ok, so today I changed the lower intake manifold gasket and the problem still exists. I even put aviation gasket maker on the gaskets to help them seal. I am beyond mad right now. I've only got two other possible ideas. Since I installed the trick flow valve covers when I swapped my heads, I had to make a vacuum/oil fill pipe and I made it on the drivers side vc. I used an AN elbow and put a hose to the air inlet. I'm thinking that the AN fitting is too tall and its not letting the upper seal. The other idea which is kind of a long shot is that I need to redo the roller rockers. Any help with my ideas would be appreciated.

Just a thought but, if your valves are not adjusted correctly, why did all this stuff just start to happen?

Sounds like a v leak and if your upper & lower is not right ...... I'd focus my attention in that area.

Good Luck!
Later
Grady

 

[johnmcgt]

problem I ran into

I recently changed my injectors and thought I would replace the hoses under my intake, with 140,000 I thought it was about time. When I did this I used regular vacume hose, car ran fine for a while then started to make a high pitched sound, almose a whistle running rough.
To make a long story short the hoses needed to be thicker walled, I used water hoses (thicker walls) and they did not collapse on themselves.

One on my life lessons, good luck,


John

 

[Franks94snake]

Have you checked your MAF sensor? Or if you have access to a stock one try swapping them, cant hurt....

 

[TrueBlue95GT]

Alright I put a vacuum gauge on a line closer to the intake manifold and the vacuum is erratic. It bounces around 14 in. Hg. What does that mean?

 

[TrueBlue95GT]

I had a friend thats a mechanic for GM look at it last night and he said that he thinks it's either a bent valve, a broken valve spring or a blown headgasket. What do you guys think about his prediction?