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Wed Sep 16, 2009 11:10 pm

I'm having a little problem. Fuel pump won't always come on during startup. I have been jumpering it a few times(at the pump with 12volt) and it would start running. Now I can jumper it and nothing until I tap the pump and then the pump pumps.
Pump going out? Clogged up? Ground going bad? I know electric motors take a little more amperage to actually start spinning from a stop than they do to keep spinning.

Wed Sep 16, 2009 11:14 pm

You check for power at the fuel pump connection when it's not working?

This might tell you whats wrong.

Wed Sep 16, 2009 11:15 pm

No, don't believe that's it if I can run a battery voltage jumper to it and it not work.

Wed Sep 16, 2009 11:41 pm

I see---

You jumpered it out from a power source, but with the ignition on,and the pump not functioning, you didn't back track on the wiring with a 12 v test light to see where the power isn't coming from.

So--what's not it?

You don't know yet cause you didn't check the wiring or the power supply.

If you have 12 volts at the pump, and it's not running, the pump is shot.

If you don't have any juice ate pump--the power supply is being delayed.

You just have to find out where with that test light.

Thu Sep 17, 2009 12:07 am

Terry Kay wrote: I see---

You jumpered it out from a power source, but with the ignition on,and the pump not functioning, you didn't back track on the wiring with a 12 v test light to see where the power isn't coming from.
A PUMP WILL ONLY RUN/CYCLE FOR A FEW SECONDS WHEN YOU TURN THE KEY

So--what's not it?

You don't know yet cause you didn't check the wiring or the power supply.
KIND OF HARD WHEN ON THE SIDE OF THE ROAD. THIS IS AN INTERMITTENT PROBLEM. YES, COULD HAVE TAKEN A JUMPER WIRE TO HOT SUPPLY OF PUMP, TO TEST LIGHT, GROUNDED IT AND TURNED THE KEY TO MAKE SURE LIGHT CAME ON FOR A FEW SECONDS BUT SINCE I SUPPLIED THE BATTERY VOLTAGE WITH A JUMPER AND IT STILL DOES NOT RUN UNTIL I TAP THE PUMP KINDA RULES THAT OUT ALONG WITH A RELAY PROBLEM
If you have 12 volts at the pump, and it's not running, the pump is shot.
UNLESS OF COURSE THE GROUND IS BAD,
If you don't have any juice ate pump--the power supply is being delayed.
UH, YES BUT NOT MY PROBLEM, WOULD NOT RUN WHEN KNOWN GOOD SUPPLY WAS USED
You just have to find out where with that test light.

Thu Sep 17, 2009 12:24 am

<<So--what's not it?>>

You don't know yet cause you didn't check the wiring or the power supply.>>

<<KIND OF HARD WHEN ON THE SIDE OF THE ROAD.>>

I didn't see this mentioned in the first post.

Whats' kinda hard--to check for juice?
Jumper out the relay so you have constant voltage ( should ) and see what happens.

<< THIS IS AN INTERMITTENT PROBLEM. YES, COULD HAVE TAKEN A JUMPER WIRE TO HOT SUPPLY OF PUMP, TO TEST LIGHT, GROUNDED IT AND TURNED THE KEY TO MAKE SURE LIGHT CAME ON FOR A FEW SECONDS BUT SINCE I SUPPLIED THE BATTERY VOLTAGE WITH A JUMPER AND IT STILL DOES NOT RUN>>

You said it did

<< UNTIL I TAP THE PUMP KINDA RULES THAT OUT ALONG WITH A RELAY PROBLEM>>

You didn't say you had to wack it to get it fired up.

<<UNLESS OF COURSE THE GROUND IS BAD,>>

You add a ground wire?

What happened?

If you don't have any juice at the pump--the power supply is being delayed.

<<UH, YES BUT NOT MY PROBLEM>>

Well, it sure is---I'm sorry--it's the Vans problem.

Your going to have to some diagnostic work here on your own.

And back tracking on the power supply wires or removing the pump & bench testing would be the only way to get this done & solved.

I don't kow how else your gonna get ths done without doing some testing on the wiring or on pump itself.

Thu Sep 17, 2009 12:56 am

Terry, I didn't want you to try to fix this from a couch. Thank you for your suggestions.

This is an intermmitent problem. If I went and tried it would start now. So how do I troubleshoot something that is not broken at the moment?

I am asking for suggestions along the lines of what I have mentioned and for any experiances that others may have.

Thu Sep 17, 2009 7:26 am

I had a similar problem and this is tough to track down especially by yourself. Mine ended up being a bad ECU, which I know is rare, but it worked. Try and find a vanagon owner locally so you can swap in a known good pump and see what happens.

Thu Sep 17, 2009 11:59 am

Mark, whoa ecu? Sorry about that luck. Maybe if I knew the amp draw of the pump that would narrow it down if pump is going out.