Thread: Cutting out Problem .. PLEASE HELP

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I have a 1976 chevy monza towne coupe. It was one of the rare ones that came out of the factory with a 305 two barrel. Well i replaced it with a 350 Four barrel. Ever since I did that , if you hammer down on it , about the time it reaches 6000 rpms its acts like it has sucked the bowl dry. It cuts out and you kinda have to tap it to get it going again. I had a 600 holly Q-jet replacement on the car. It was a single pumper but it was a duel feed. I replaced the factory fuel pump with a high output holley electric fuel pump and that didnt help any. So i changed out the holly carb with a Q-jet four barrel I had laying around ( i had it rebuilt first) and now it cuts out around 5500-6000 some times 4500. With the randomness of the cut out could I possible have a collapsed rubber fuel line? because there is rubber leading into the metal line I just havent botherd to change them because the fuel lines on that car are EXTREMELY hard to get to . Any thoughts?

#1 an electric pump works best back by the tank so it can push. if your cutting out at 55/6K what is the cam rated at? You said you changed it??

Could be that or simply a dry rot in the hose that lets it suck air. Or it could be that the sock on the pickup tube in the tank is clogged up. P.S. Don't forget about the rubber back by the tank. And as Charlie said an electric pump is designed to push not suck.

The pump is located back by the tank in my trunk and im not sure about the cam I bought it and my dad had someone put it in because he said he didnt have the time to show me how to do something like that.

Originally Posted by Slade1134

I had a 600 holly Q-jet replacement on the car. It was a single pumper but it was a duel feed. . Any thoughts?

The holley replacement carb for the quadrajet was a single feed, in the front, if it had dual feed bowls on it ( someone had switched them out ) the pump transfer slot in the metering plate to the bowls would not line up, therefore that is what created your first problem.

But I never had this problem until we put the four barrel on there so thats kinda what made me think it was something fuel wise

As stated above i would start at the tank, move pump to the tank, replace all rubber lines, filters, all the way up to the carb. Then see if the problem persists.

Thanks ill try that soon

If yur holley looks like this (4165 ) it has correct bowls, if it has dual feed bowls its incorrect, look at the front of the carb for the carb listing number... if you decide to stay with the quadrajet you`ll need to start here..
Rochester Quadrajet Carburetor Rebuild Parts Bushings Unwarping Services keep us updated...decisions decisions......

that pic of the holly looks correct ... Which do you recommend i keep the holly or the Q-jet? Both carbs have been rebuilt

That is something you`ll have to decide, I`m a holley person myself, you`ll need to start from the back and work forward, it could be something very simple.....here are some more holley tips, got one more for quads but...for the rookie I would run the holley, quads are good but if your new to them they are very troublesome.
Carburetor Tuning the Scientific Way

Thank you! Im gonna print that out and read over it. Im also going to replace all my rubber lines. That should be fun :C .

Just a little update, this problem was fixed with the replacing of my fuel pump, lines, and filters. I had really bad dry rotted lines coming from the tank so it was sucking air instead of fuel

that will do it glad you got it fixed