i know it's a long shot.. anyone got one i could borrow?

its a 1980 rabbit truck
at the pump terminals (with pump not attached) i'm seeing 11v
at the terminals w/ pump running it's like 7v

current draw is 8 amps. service manual says to replace the pump if it's pulling more than 8.5 amps.

i'd like to test the pressure before i drop ~$180 on a new fuel pump... but i'm pretty sure it's soiled the sheets

10/12/2006 12:19:36 PM

How sure are you? Why only 11v at the terminals? I wonder what kind of current it would draw if supplied with 12.5 volts or so. You have any wiring issues that you know of? That generation was FAMOUS for having a truly shitty electrical system.

As far as the fuel pressure tester, I have a gauge that will go up to about 100psi I think. But the CIS system goes even higher than that, doesn't it? Like 70-110psi. I would be tempted to fab my own using a cheap air gauge and a length of fuel injection hose.

10/12/2006 1:58:01 PM

good point about the current at 12v... i dunno what the exact voltage is with/without the pump disconnected.. also, we had been trying to crank/diag it, and i think the battery was getting tired..

the wiring was fucked, but i replaced the chewed up section. no real change in the readings..

fuel pressure is about 75psi (5 bar), but from what i've been reading i need some kind of special fittings to hook into the CIS system b/c it uses that goofy fuel distributor.

i think i have a good pump in my project car.. i may pull that and see if that'll help get the truck running.

10/12/2006 4:56:54 PM

How about your warmup pressure regulator?

What you are describing is a fuel-related no-start. The engine is running off the burst from the cold start injector only.

[Edited on October 12, 2006 at 5:21 PM. Reason : lll]

10/12/2006 5:20:34 PM

there's spark for sure. timing is definitely off.

starter turns... very sporatic popping in the intake mani/boot (think backfire) that likes to pop off vacuum lines.

the distributor hold-down was loose and we were gonna try to adjust it until it actually ran somewhat, then put the timing gun on it.

the thing that makes me thing it's the fuel pump is that the voltage drop and the fact that it's seeing almost the "replace it no matter what" amperage

[Edited on October 12, 2006 at 6:00 PM. Reason : intake backfire is maybe once every 4-5 seconds when i'm turning the key to start]

10/12/2006 6:00:01 PM

Are the plugs gettin' wet at all? You know that you'd have to have a hellacious drop in pressure for the thing not to crank at all due to fuel pressure--injectors have a pop-off pressure of around 45 psi. If the pump was seized, your amperage draw would be a lot higher.

10/12/2006 6:45:22 PM

been down that toad before with my brothers old GTI it turned out to be an ECU

call lonnies in durham, lonnie is pretty cool and he knows his shitty vw's

10/12/2006 7:33:43 PM

K-Jetronic doesn't have an ECU.

Well, unless it's KE-Jetronic or K-Jetronic with Lambda.

But the '80 VW was regular, I believe. Totally mechanical system.

10/12/2006 8:33:47 PM

yeah.. it's the old shitty...

i'm gonna go pull the pump of my project car and see if that helps (it was also CIS in its time).. or i may pull an injector and see if it's spraying.. probably get to that this weekend..

the pump may just be gummed up.. the last inspection ran out in '04, iirc, so it's been sitting awhile.

[Edited on October 12, 2006 at 10:44 PM. Reason : ..]

10/12/2006 10:43:26 PM

You can get one from harbor freight for $15

10/12/2006 11:13:25 PM

Quote :

"call lonnies in durham, lonnie is pretty cool and he knows his shitty vw's"

Yes he does, got a vanagon off him last year. Very good guy

10/12/2006 11:14:06 PM

well we started messing around with it this weekend.. swapped over the fuel pump and replaced the filter... still nothing.

we decided to check out the timing and apparently the previous owner was a moron (didnt run when i got it a week ago) and put the plug wires in wrong..

we fixed that and now it starts, but wont hold idle... could be the gas thats in there, the autolite plugs (who puts autolites in a vw?) or the fact that it was like 35 degrees out when we were trying to start it

10/16/2006 10:54:31 AM