I recently pulled the 350 on my 71 Skylark. It had various leaks, like the oil pan, front timing cover and rear main. I cleaned and repainted engine as well. I also had purchased a TA Stage 1 intake several years ago from a member in here and finally installed that while I had the engine out. Lastly I had the carb rebuilt as well. It is a Holley 600. That was what was on the car when I bought it. So the issues I am having is it runs fine until it warms up then it starts dying like it runs out of fuel. I can restart and it will start but will die again. It will stay running if you give it throttle but if I put in gear it dies whether I give it fuel or not. What could my issue be? The intake is getting really hot, could be vaporizing the fuel?
I have a vacuum gauge hooked to it and it’s holding at 21 in of pressure. And we have been playing with the timing, and it’s doing the same no matter what we have it timed to. I put a pertronix dist. And started with the timing the instructions suggested.
Had a similar issue, but it was an old HEI distributor. The wires coming off the pickup were broken and when they got hot would lose contact. but you’re using a new distributor? what else did you change when the engine was out? Vacuum leak sounds plausible. It’s reading a steady 21” of vacuum? No jumping of the needle? Is the carb tuned appropriately? It runs when choke is on - rich condition. Will run when warmed up if you give it gas….
I’m just thinking: If it ran before and doesn’t run now, what changed? Sounds like a vacuum leak is plausible. could be leaking at the base of the carb, intake manifold, brake booster…. I’d think it would be a pretty big leak to cause the engine to stall. It’s an automatic trans? Check the modulator as well for vacuum leaks. As for the carb, is the curb idle set properly? Did you make sure the transfer slots were just barely exposed before bolting the carb on? If you had a bad vacuum leak, I’d also think the mixture screws would be pretty far out to accommodate.
Needle is not jumping, sprayed brake clean around the carb base and intake manifold, no leaks detected. Carb was rebuilt before I put it back on. Pretty confident the guy who rebuilt it know what he was doing
Did you check the modulator for leaks? Is the Pertronix new? Timing set with light, vacuum advance disconnected and plugged? what’s your curb idle speed? What happens if you apply choke with the engine warmed up?
It sounds to me like you have a section of the rubber fuel line that is on the suction side of the pump that has a small crack opening up , as in dry rot. When this takes place it’s much easier for the pump to draw in air then the much heavier fuel, and in fact you may not even see signs of a fuel leak with this condition. many times the fuel line coming up out of the tank is shot and unfortunately the last section of original hose to get replaced. another culprit can be the fuel sock in the tank is so loaded with crap that the fuel pump just sucks it closed. These are another item that usually does not get replaced until it’s a issue!
Sounds like it is running out of fuel I would check those lines for leaks I had a rubber line under the door on drivers side that had a leak in it small rubber hose there. I would look at all lines that are rubber that feed the engine. Plus the sock in tank could be plugged up, at one time I took the line off and used air to blow backwards to the tank in case the sock was plugged. I used low power air so it would not blow the lines off and when I heard the air bubbling the tank I stopped. When I did take the tank off a few years later the sock was smashed shut was not plugged but there was crap starting to plug up most of it.
You need to find out what you are losing when the engine stalls. Does it run rough, stumble, and gradually stall, or is it like a light switch? If it is sudden, that points to ignition. Tell us more about the Pertronix distributor. What ignition did you have before? If it was points, does the Pertronix need battery voltage, or will it run with the resistance wire? Did you use a matching coil, or did you use your existing one? Holley carburetors have big fuel bowls. It would take the fuel pump giving up completely, and then it would gradually run rough and stall as the fuel bowls got low enough to stall the engine.
My shop had a gto engine to rebuild. When customer installed and run , failed to notice heat riser valve was closed. Overheating engine. When they give it to me paint on block had turned colors. (Dark) , My take on it was guy wanted the heavy overlap cam sound but with the original carb AFB ? . This time engine was test run before customer gets it. Little vacuum. Now I see new boxes Edel intake × carb. I believe this 3rd time. Matter of fact another poncho we had put together for a guy went into a car the guy had bagged, but exhaust pipes were so tucked close to floorpan the carpet went to fire. Tee Hee.
If I were guessing, (and I am), this sounds like a carb issue to me. We all make mistakes. See if there is another square bore to swap in for a quick test.
Update: this morning my buddy came over with a spare carb he had. Installed and started doing the same thing with a different carb, so we eliminated that issue. Played around with timing for a little bit. Don’t know why we came to the ideal of changing out the coil, but we called around and the local CarQuest had a pertronix flame thrower coil. I had a new coil on it but it wasn’t a pertronix coil. So that was the issue. Drove it around all afternoon and no issues. Thanks everyone for the suggestions
Good luck with Pertronix. Had their plug & play billet distributor & coil on my boat and it was a P.O.S.
Lots of Pertroix/coil issues. I'm thinking about using points to trigger a hidden (new smaller version) MSD on my next build.
Pertronix needs to revamp their whole design if you ask me. That company just pissed me right off.... never ever again ...I'd run stock points before Pertronix. The reason you change ignition is to be problem free and have steady spark.
