I own a 1974 Stingray. When I purchased her, I drove her home witch was a 6 hour drive. Now the ex owner said there was a vacuum leak I had to locate and fix and in the meantime adjusted the idle very high so I wouldnt stall driving home.  Well I took her to my mechanic who said that the carb was the wrong carb and didnt fit with my intake thus creating a vacuum leak. I found this weird as the carb is a street avenger and the intake a edelbrock performer 2101. But this mechanic has a great local reputation and worked on my previous Vettes...so I trusted him and gave him the okay to replace the carb. Well carb replaced and I had basically the same symptoms: Car runs fine when cold but once it gets warmed up, it will stall at idle if I stop at a light. When it gets really warmed up, it stalls even at a stop. But except for that she seemed to be driving really nice untill you stop........Took her back to my mechanic who checked the timing, and readjusted the carb a few times and had me do roadtests to see how she would handle. Well she seemed to be less worse and stall way less often. Even drove this korning and she didnt stall at all and I adjusted the idle to 700 rpm like the haynes manual specifys. All seemed ok. So I go for a good drive on the highway this afternoon and I noticed she seemed weird, like low power and sounded weird so I drive back home but as soon as I leave the highway, she stalls. Start her back up: as soon as I take my foot of the gas, she immediately dies! I had to drive her home with a foot on the gaz and a foot on the brake when slowing down!

My mechanic had disconnected the vacuum hose from my distributor to the carb and had basically ruled out the possibility of the problem being a leaky hose. So Im gussing intake gasket and the ex owner believes its the intake gasket. So I took off the intake today and will be putting her back together tomorrow.

 

My mechanic wants me to bring him my carb so he can change the power valve. he the carb needs a powervalve for the cam I have witch would solve the idle problem.

 

A few questions: does this sound like a vacuum leak problem??? My problem was originally an idle problem and now she dies without my foot on the gaz! Could I have a couple problems at the same time? Would really appreciate some opinions on this.

 

Secondly, for those who have changed intake gaskets before, Ive read that I shouldnt use the gaskets for the rear and front ends between the block and intake and instead use black silicone. What do you guys suggest. Amnd should I put some silicone or something on the intake gaskets or just slap em on dry?

 

Let me know and sorry for the long question.

 

Chris

 

Use "Right Stuff" sealer for the front and rear intake seals. Better sealing qualities than standard RTV - I've never had an issue with it.

 

 Put a 1/4" bead across the front and rear rails and an extra bit where the intake gaskets meet the sealer on the 4 corners.

 

Good luck - hope she straightens out.

The Cam is a Comp Cam: Comp Cam XS256S cam & lifter (218/224 , 0.465/0.477) and the heads are Edelbrock: Heads: EDL-60909 heads, 64cc

 

From what I understand that cam is a mild cam right? Anyways, I dropped off my carb at my mechanic and he will change the power valve and I will finish the intake job tonight or tomorow and Im hoping that the problem will be solved after that!

 

If not, I guess the only other possibility is ignition although most of it is new....

 

 

Ill keep you guys posted once Im done but feel free to share opinions and experiences on similar problems.....Im starting to wonder about my ignition module and fuel pump...although I think I wonder too much

 

Well I didnt notice any black smoke but I didnt really check that to be honest. The thing is at first it was only an idle problem but has now become a stall as soon as you take your foot of the gas problem and this after a long drive on the highway.....Well after changing the intake gasket I will redo my timing and adjust the carb! If the problem is still there then I will disconnect the powerbrake vacuum hose to see if theres a leak from there....

 

 

 

Thanks for the reply. What is the best way to check the fuel lines?