I have a 403 that was freshly rebuilt in my 85 cutty. The other day I was driving it and I got to a red light and when it turned green I gave it gas and it died on me. I checked the carb and no gas was pumping through. After 15 minutes of messing with it I got her running and took her home. Since the only thing on the car that wasnt new was the fuel pump I changed it out and drove it to the store and it ran fine. On the way back home I get it to another red light and it does the same thing. After 15 minutes of messing with it its starts to work again and I get her home. The carb is new from Summit its a rebuit q-jet 1972 model. I had the carb on my 307 for a month before I put this new motor in and never had an issue till now. I changed the fuel filter at the same time I did the fuel pump so I dont think that is the issue. I have an Edelbrock thunder series 800cfm here but is that too much for this motor? Its just a mild build 403.
problems with my 403
- Thread starter shorty74
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Whats your timing set at? Sounds like its possibly too far advanced. Also, you may have a vacuum issue. Could also be a vapor lock problem as well. You still have the vapor canister hooked up? If its plugged, there maybe a vacuum in the gas tank sucking gas from the pump? Just a thought....shorty74 said:
Sounds to me like you definitely have an issue in the fuel line ... like vapor lock or something pluged up. Make sure your line is free (no kinks) and its not running to close to engine manifolds or exhaust. A vapor lock condition 99% of the time happends on the suction side of the pump. And yes I agree it could be the fuel sock in the tank
I had a defective coil that would heat up the module and shut it down after driving it a little while. The modules have overheating protection so when it cooled down at 15-20 minutes and reset the car would start up again. The coil wasn't that old either....
Time for some troubleshooting!
1. Was anything modified with the fuel system when you swapped engines?
2. Did the fuel line get kinked?
3. Fuel filter not backwards (depending on which one you're using)?
4. Any dry-rotted hoses between the tank and hard lines? This happened to me before BTW.
5. Are there any fuel hoses between the fuel pump and carb, or just the original hard line? If it's been modified with rubber hose, make sure it's not pinched or collapsed.
Start simple and trace anything you touched during the swap before jumping into everything else.
1. Was anything modified with the fuel system when you swapped engines?
2. Did the fuel line get kinked?
3. Fuel filter not backwards (depending on which one you're using)?
4. Any dry-rotted hoses between the tank and hard lines? This happened to me before BTW.
5. Are there any fuel hoses between the fuel pump and carb, or just the original hard line? If it's been modified with rubber hose, make sure it's not pinched or collapsed.
Start simple and trace anything you touched during the swap before jumping into everything else.
It could be as simple as a sticking float needle. Pull the filter off and be sure it's clean. Leave it off. Then take a section of steel fuel line with the nut, cut it short then add some rubber fuel line so you can blow through it. See if the needle and seat will let you blow through it. With an empty bowl, it should flow easily. A full bowl should not flow at all. If you cannot blow through an empty bowl, open the carb and see why.
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