1980 Trans Am 301 4.9L Turbo Indy Pace - Vacuum Issues?

[johnny68]

I live in Port Charlotte, FL, area 33954.

I have a 1980 301 4.9 turbo Indy pace car.

Untouched engine.

I have a vacuum leak and I cannot fin itd.

I’m looking for someone near me with a 1981 turbo or a 1980 Trans Am 301 4.9L to compare vacuum systems.

My car will not stay started; it just stalls.

I can drive it if I keep the engine revving.

The carburetor was rebuilt and is the original one.

Of course, your car has to be untouched, with the same carburetor that came with your 301 4.9 turbo.

Notes:
EGR, grommet, and PCV valve were changed out.
Carburetor rebuilt.
Ordered a new canister too.
Spark plugs are new.

Help if you want to compare systems.

Thanks
Johnny68

 

[Aus78Formula]

Start at the intake and carb and work from there, where the vacuum comes from. How do you know there's a leak? Other ways are to spray a mist of water or engine start spray around suspected leaks, see if idle increases or lowers etc. But could be anywhere, why do you suspect there is?
Do you have factory vacuum diagrams and manuals for you model? Emissions sticker on support still?

 

[johnny68]

Yes thank you

I’ll try the water trick today.

After reading many forums and putting all this together I did find a major leaks so far.

The grommet and pcv value were bad. Now car stays started but still shakes. And the fumes I was having. Getting a new canister resolved that and most of the shaking. One more thing the PERV valve was leaking I had that rebuilt at TTA. The car was stalling as well. That’s still here. The fuel pump is original. I’m getting that swapped out. That and hopefully is the shakiness and stall it get.

Water trick today.

Thanks for your commments. for me

 

[Aus78Formula]

Make sure fuel cap is the type that breathes and has valve. For testing you can even remove it, make sure not under pressure as sucking against it. Although not a vacuum leak, it'd be idling tough like starving for fuel against the pump

 

[johnny68]

Start at the intake and carb and work from there, where the vacuum comes from. How do you know there's a leak? Other ways are to spray a mist of water or engine start spray around suspected leaks, see if idle increases or lowers etc. But could be anywhere, why do you suspect there is?
Do you have factory vacuum diagrams and manuals for you model? Emissions sticker on support still?

How do you test the intake manifold?
And I have the factory diagrams too.

Make sure fuel cap is the type that breathes and has valve. For testing you can even remove it, make sure not under pressure as sucking against it. Although not a vacuum leak, it'd be idling tough like starving for fuel against the pump

kill check that. How do I check for manifold leaks?
I’ll spray hoses to any other vacuum leaks I might have. Ill check gas cap this morning before I start it. Or should I have car running a bit to build up pressure first, if so be it?

Thanks again

 

[Aus78Formula]

So is there a vacuum leak, or just guessing a symptom to engine running rough?

 

[johnny68]

So is there a vacuum leak, or just guessing a symptom to engine running rough?

Hello,

I had family come over so I have not done the spray water test yet. I will tomorrow morning. Please stay in touch Aus78

Johnny68