no fuel at start up
mudrunner80
04-25-2010, 08:06 AM
I just bought a 79 w/350 it was in pieces basically when I got it. It is strictly for mudrunning but my problem is I can crank it until the battery dies and no start but when I pour fuel down the carb it'll start right up and stay running and restart no problem but everyday 1st start it needs to be primed. I have'nt taken a pressure check yet. Any ideas? Thanks in advance
roblo101
04-25-2010, 03:03 PM
Sounds to me like fuel pump, pump has to put out more pressure when starting cold. Then after it has filled the lines an carb, does not need near the pressure to start an already warmed engine.
Also would not hurt to check your fuel filter.
Now I am no Tech, just two things to look at!
Good luck and keep us informed, please
Rob
Also would not hurt to check your fuel filter.
Now I am no Tech, just two things to look at!
Good luck and keep us informed, please
Rob
mudrunner80
04-25-2010, 06:55 PM
I suspected the pump I just gotta get alittle better before I go crawling on the ground. I actually bypassed the filter 1st with no luck. I figured a fuel pump would either work or not. not get weak.
Ryan Hermann
04-25-2010, 09:57 PM
Your fuel pump probally has a cracked diaphragm. It the fuel will drain back to the tank and then it takes a while to get fuel back to carb. Have a 69 Gmc grain truck that does the same.
ken_man_1
04-26-2010, 08:01 AM
Since you bypassed that filter, when you replace your pump, put a new filter back in there!!!!!!!!!
mudrunner80
04-26-2010, 08:25 AM
oh I definately plan to. I only bypassed it to get direct feed. I keep forgetting to put mu fuel pressure tester in my truck when I go. Its parked at a friends house. Thanks for the help. I'll replace the pump and go from there
j cAT
04-26-2010, 09:34 AM
oh I definately plan to. I only bypassed it to get direct feed. I keep forgetting to put mu fuel pressure tester in my truck when I go. Its parked at a friends house. Thanks for the help. I'll replace the pump and go from there
the fuel pump has a spring that breaks , then you will have poor pump pressure...the pump has a diaphram when this ruptures gas will leak out the pump weep hole....check your fuel lines for leakage...if you have a small leak on the supply side , this will also reduce pump pressure,,
when the pump is removed you will in most cases see the the pump is defective with the operation of the pump arm with your hand ..
with a metal fuel tank removal of the fuel filter is a very bad idea...how about replacing the fuel filter to see if this was the problem..you may have created more trouble ............
since it runs after you dump fuel in it did you check for the proper choke operation ? choke pull off's vacuum leaks etc ...this will all cause a poor cold start on this type vehicle........
if you have a poor choke fuel will not be sucked out of the carb...if you pump the throttle 5 times and it starts then stalls it is usually the choke...
the fuel pump has a spring that breaks , then you will have poor pump pressure...the pump has a diaphram when this ruptures gas will leak out the pump weep hole....check your fuel lines for leakage...if you have a small leak on the supply side , this will also reduce pump pressure,,
when the pump is removed you will in most cases see the the pump is defective with the operation of the pump arm with your hand ..
with a metal fuel tank removal of the fuel filter is a very bad idea...how about replacing the fuel filter to see if this was the problem..you may have created more trouble ............
since it runs after you dump fuel in it did you check for the proper choke operation ? choke pull off's vacuum leaks etc ...this will all cause a poor cold start on this type vehicle........
if you have a poor choke fuel will not be sucked out of the carb...if you pump the throttle 5 times and it starts then stalls it is usually the choke...
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