What the Heck

eric_ciampa · 03-24-2003, 02:44 PM

this is interesting... Ok so i go out side to me car this last morning and i hear the sound of some sort of fan running... get closer and reconise that as my fuel pump just pumping. Very confused since the ingition was off with the key removed!!! I pulled the plug going into my AFM (i know that has a fuel pump relay that works with the ignition on) and nothing. I had to disconect the positive Battery cable. So what is going on?
I have to confess that a unexpected rain came the other night before this problem and i accedently left her uncovered (the rain try is out of the car)... i checked it today after everything is dried out and still runs when the pos. cable is placed back on. any ideas?

philinjax · 03-24-2003, 03:11 PM

Here is my shot in the dark to fix the problem. Pull the power supply relay off the relay panel (it's the one in the middle of the board), unplug the double relays located next to the battery tray. Use a hair dryer on the power supply relay socket and the double relay sockets to remove most of the moisture. Spray the relay sockets with a contact cleaner and lubricant (you can get it at Radio Shack). Plug the relays back in.
See what happens.
Phil

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Odds are pretty good that you have a bad double relay. If not that, then the inputs to the relay are incorrect somehow. EJM posted a note with the pinouts of the relay recently, either here or on the 914club board. Check your relay socket against that.

If that doesn't show a problem, then the relay is most likely faulty. You can check the fuel pump contacts in the relay after you unplug it, too. With no power going through anything, there should be no connectivity between 88c and either 88y or 88z.

--DD

Jim Smolka · 03-25-2003, 04:50 AM

Sometime in the past 30 years, a PO could have installed an 'aftermarket' wiring system.

If my memory is working correctly and a 1.8 L-Jet is similar to a D-Jet System, the ground path for the FP relay coil goes through the brain box. Could be a short to ground in the wiring to the brain, or a faulty ckt inside of the brain. An easy test is to remove the T-4 connector at the relay board. Of course this assumes the wiring is stock.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

L-jet fuel pump wiring is rather different from D-jet.

I suspect the double relay, or the wiring that goes to it.

Oh, another worthwhile question just occurred to me--
Did you (or anyone else) change anything between the time that the car was working normally and the time that you noticed it wasn't? Always a good question to ask... "Hmm, this part isn't working now. What did I fix since the last time it worked?"

--DD

Jim Smolka · 03-25-2003, 10:30 AM

Dave,

Thanks, I did not have my wiring diagrams in front of me...

eric_ciampa · 03-25-2003, 12:32 PM

ya actually you both are part right. The PO actually re-wirred parts of the harness including the fuel pump so actually right i dont use any of those 4 contact points on the board opposite the batery. I when through the double relay and cleaned and re-attached and no difference. Also this does not seem to be affecting any other system and the car runs fine. I also looked at the actual fuel pump and didnt see anything concerning. How can i check the double relay to see if that is whats going on? you also mentioned grounds any ideas on those? I will take a closer look at it later tonight or tomarrow... thanks

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Do a search here and on the 914club BBS for posts by "ejm914". He posted what the pins in the double relay do. This relay hangs off of the battery tray, and is what powers the FI and the fuel pump.

The 1.8 should have one wire hooked up to the four-pin connector on the relay board. I forget what exactly it does, but I believe it is important to the FI.

The fuel pump should have two wires, a power wire and a ground wire. The power wire runs to the double relay (might go through the relay board, I forget!) and the ground wire goes directly to ground.

A hacked wiring harness is a very bad sign. If someone re-wired the carr and changed the functionality of anything/everything, you should pray that he made diagrams to help out. Otherwise you'll have to figure out everything pretty much from scratch. Ugh.

--DD

ejm914 · 03-25-2003, 05:16 PM

Eric - It sounds like you may have gotten water into something. Unplug the connector at the relay with the colored wires and see if the pump shuts off. If not the problem may be in the relay board, the pump uses T12/12 in from the dual relay and T14/13 out to the pump. L-jet used Terminal T4(2),it's connected to terminal 86a at the relay and supplies the "engine cranking" signal from the starter solenoid circut. Without it you may have a hard or no start problem.

Here's a link to the dual relay pin-out.

But if your wirings been modified anything is possible.

Water shorting out the dual relay can be a very bad thing. The relay has connections to the battery, ignition and starter. Parked in the rain and still in gear you might find the car is not where you left it.