Fuel pump issue?

[Mr Singh]

Hey folks

I seemed to have developed a odd fault in the Astro. All of a sudden the van cut out, so I pulled over and waited for a while. Turned the key, could't hear the fuel pump prime. So I waited. Tried after 5 mins, nothing. Tapped the fuel tank, nothing. Grabbed the fuel pump wiring harness (round cylinder shape with 10-15 wires?) and shook it a little, what do you know it primed and started!

It ran a little rough but got me home. Its parked outside my house now and it runs fine and primes, but switches off on idle after 20-30 seconds. Now, I've already changed the fuel pump last year and fuel filter for a Delphi one.

Could be a intermittant connection in the wiring harness? Or was it luck that shaking the harness made it work again?

Thanks,
Am

[LiftedAWDAstro]

I would guess the pump is going. There is a relay in the fuse box under the hood. You can swap it with the A/C compressor relay or another that is the same just to rule it out. Next step will be to put a fuel pressure tester on the fuel rail and see what the pressure does. Pull all the connectors apart and check for corrosion as well.

[Mr Singh]

The delphi pump has barely covered 500 miles since I fitted it, and the fram fuel filter.

I know this problem happened to me last year in October coming back from a show it just cut out 1/4 mile from my home. Pulled over and wiggled the harness under the van next to the tank and it was all fine for 5 months (as you can tell I dont drive it much!)

I will pull the connector apart and give the contacts a clean with a plastic brissle brush and some electrical contact cleaner.

[Rileysowner]

Check the wires that go to the fuel pump carefully to make sure this is not a wire that is failing while you are at it.

[cd0156]

This sounds very similar to what I'm chasing at tthe moment.. Van sometimes won't start, usually after it's first shut off. Wait 20 min and it will run again. Last night it died on the road, waited, it started and drove about 10 miles, then died.. Did this three times then forced me to call a cab.. This morning I went back, started up fine then when I shut it off at home it refused to start again.. New fuel pump in september/October..
I put a pressure guage on it and sure enough, when it won't start there's no fuel. Wait 20 minutes and the pump primes, pressure is up, and it starts. On/off a few times and it loses the pump and won't start.. Wiggling the connector seemed to work a few times but seems to be coincidental. I checked and do have voltage past the connector.. I checked resitance thru the plug at 0.0 on the grey 12v and the center black ground. I ran a cable all the way from the negative terminal on the battery and checked resistance from that to the pin in the connector at 0.01.. Pretty good for that far apart!
I read somewhere online that the connector at the actual pump has been known to be faulty, and it is reccomended to replace it when the pump is replaced.. Unfortunately I had a mechanic change the pump so I don't know if he swapped the harness also.. And since I can't see how to get to it without dropping the tank it's gonna have to wait till tomorrow. I did cut and strip the ground cable between the connector and the pump and the conductors are pretty black and corroded, so I think I'm on the right track.. This may have been the cause of lots of my issues over the years.. Especially since the fuel guage has been shaking for the last five years or so..
I'll let everyone know tomorrow night what I find in the pump plug...

[Smiliesafari]

It may not be the fuel pump. If the coil is in failure mode letting it cool a bit may allow it to work temporarily.

[cd0156]

wHat coil would that be?

[Smiliesafari]

Ignition coil. It's on a bracket over the right side valve cover. Follow the coil wire from the dist cap. It will take you right to it.

[cd0156]

That wouldn't cut fuel tho....

[Mr Singh]

Well.. This definatley is the round plug under/next to the tank.

I broke down this weekend, pulled over and while a friend turned key i shook that plug, and u could hear the pump prime on/off as though there was a break in the wire. I drove it for 30 miles and no issues. I need to jack up the van and continuity test every cable from the backside pins as I'm sure one of them is corroded and failing.

There is no reason why the pump would go after 550miles of use, unless it was a cheap piece of poop!

[cd0156]

That's what I was thinking!! Unfortunately, I have power past the round plug when the pump is not working.. :(
the wires on the round plug:
-black (center pin) fuel pump ground (this goes to a bolt right above the plug.. Make sure it is tight and has a good ground! I cleaned mine up a little just to be safe.)
-grey 12v to pump

the rest are for the fuel level sender and such, but those are the two for the pump! ;)

[Mr Singh]

That's what I was thinking!! Unfortunately, I have power past the round plug when the pump is not working.. :(
the wires on the round plug:
-black (center pin) fuel pump ground (this goes to a bolt right above the plug.. Make sure it is tight and has a good ground! I cleaned mine up a little just to be safe.)
-grey 12v to pump

the rest are for the fuel level sender and such, but those are the two for the pump! ;)

Fantastic, I'll check those out and report back

[Mr Singh]

UPDATE:

I limped home yesterday after some SPL testing in the middle of a field it ran like dog poo, spluttering and not idling at all.

So.. enough was enough I knew there is an issue under the van with multi-plug loom. With the help of cd0156, I managed to identify the cables and cut them making another waterproof connector. I took off the ground strap and cleaned the contact surface with a wire brush attachement on the drill. Put a blob of vaseline on the bolt with a fat washer and it runs PERFECT!

I think it was the grey wire which power the pump as everytime I shook or move that plug it would trigger the pumps operation.

Either way its a great thing, It was always tense experience to drive it not knowing if I was going to break down at the next traffic lights hop out and shake the plug just to get it going for another 20m lol.

THANKS!!!!!!!!!