[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

Re: [T3] 1971 Fastback with fuel injection, no start!

On 10 May 2006 at 1:24, a.sterrett@att.net wrote:

> The Fuel Relay, checked with the key on has 12v at 30/51 and 12v at
> pin 86. I do not get 12v at pin 87 at any time, which according to
> John Muir's book means the relay is not good. 

First put your hand on this relay while you turn the key, just to see 
if you can feel it click. I assume that you you won't feel anything.

Before you decide, you need to check to make sure that the fuel pump 
relay is actually getting power. There are a couple of ways you can 
do this.

1) Remove the white plastic plug that normally brings power to the 
relay. Use a small pair of clip leads to bring an independent 12V to 
the 2 terminals you just exposed. If the relay now clicks, then you 
know that the relay is actually okay and that it just wasn't getting 
power before. If the relay clicks AND you hear the fuel pump running, 
you know that the relay, the pump, and the wiring in between are all 
okay. If the relay clicks but you don't hear the pump, then check for 
voltage on the output side of the relay: There should be 12V there 
any time you have the clip leads connected.  


2) Leave the white plastic plug attached to the relay and stick the 
probes in the back end of this connector so that they make contact 
with the 2 terminals inside. While you're watching the meter, turn 
the key ON. You should see ~12 V there for about 1 second. If you 
don't, there is something wrong farther up the chain. If you do, but 
the relay doesn't click, then the relay is bad.

> Jim, do you have another relay that I can get or can anyone tell me a
> source for this relay. I can return the one you sent if you would like
> to check it out and maybe I am doing something wrong.

Run thru some of these tests and let us know what you find. If the 
relay I sent you was bad I'll send you a tested good replacement 

I'm afraid, however, that it's most likely that there's some problem 
upstream of the relay. With a little luck, it may be easy for you to 

Bob mentioned one more test which you should do if the relay doesn't 
seem to be getting power. Go to the engine compartment and find the 
plastic connector that is against the front wall (front is front) 
just ahead and left of center of the engine. It may be held there 
with a nylon cable tie. It is an inline splice between 2 wires.

First make sure that the 2 wires are actually in there and securely 
connected. Then, if you've still got no response from the relay, turn 
the key ON and use a wire to short between those 2 wires and ground. 
That should energize the fuel pump relay. 

Let us know what you find.

Is this an old car which has not run in years, or did it just quit 
suddenly? Was something done to it recently, some work done on the 
car after which it wouldn't start?

Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA

List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]