tempermental '83 GTI

[mainadroj]

Hey, my name's Jordan.

I recently got an '83 GTI. I have had some problems getting it to run, but I am very close. I had to replace my fuel distributor, fuel filter, spark plugs, clean out the fuel pressure regulator (the thing bolted to the block), among other things. The car has been sitting for 5 years, or so, but I have made lots of progress. Now I will get to my current issue. I can get the car to run (for about 10 seconds) if I put a jumper in the fuel pump relay slot, prime the CIS system, but THEN I have to put the relay back in to get anything. After priming the CIS, and with the relay back in, it will run for a few seconds. So, it seems to me, the relay controls the spark, along with the fuel pump. (no spark at plugs without the relay in.) But the problem I am having is finding a correct relay. I know it will run, (it does for a few seconds), but as soon as there's no fuel, it dies. So, I have decided it's a bad relay. (at least the pumping part.)

A weird issue, when I put the (bad) relay in, and multimeter the spade connector 6 inches past the pin going to the pump, I have ~12V. (had to run a new wire to fuel pump, spliced in a new wire.) However, when I touch my new wire to the spade 6 inches past fuse box, I get massive voltage drop, to like .2 volts. I am thinking this confirms that the relay is bad.

So, after searching the forum, I have found this site link, but the relay I pulled from the GTI had a pin in the middle, smack dab in the center of the relay for a total of 6 pins, so I am not sure if this is the correct part.

If anyone can help me with finding a relay, I will have a rabbit back from the dead!

Anyway, Thanks for everything

Jordan

[rabbitnothopper]

Hey, my name's Jordan.

I recently got an '83 GTI. I have had some problems getting it to run, but I am very close. I had to replace my fuel distributor, fuel filter, spark plugs, clean out the fuel pressure regulator (the thing bolted to the block), among other things. The car has been sitting for 5 years, or so, but I have made lots of progress. Now I will get to my current issue. I can get the car to run (for about 10 seconds) if I put a jumper in the fuel pump relay slot, prime the CIS system, but THEN I have to put the relay back in to get anything. After priming the CIS, and with the relay back in, it will run for a few seconds. So, it seems to me, the relay controls the spark, along with the fuel pump. (no spark at plugs without the relay in.) But the problem I am having is finding a correct relay. I know it will run, (it does for a few seconds), but as soon as there's no fuel, it dies. So, I have decided it's a bad relay. (at least the pumping part.)

A weird issue, when I put the (bad) relay in, and multimeter the spade connector 6 inches past the pin going to the pump, I have ~12V. (had to run a new wire to fuel pump, spliced in a new wire.) However, when I touch my new wire to the spade 6 inches past fuse box, I get massive voltage drop, to like .2 volts. I am thinking this confirms that the relay is bad.

So, after searching the forum, I have found this site link, but the relay I pulled from the GTI had a pin in the middle, smack dab in the center of the relay for a total of 6 pins, so I am not sure if this is the correct part.

If anyone can help me with finding a relay, I will have a rabbit back from the dead!

Anyway, Thanks for everything

Jordan

6 pins use the fuse on the fusebox
5 pins bypass that and use fuse on the relay

5 pins are for early rabbits
6 pins are for westy rabbits/gti


and yes, the ignition controls the fuel pump
it sends a PWM signal to the igntion control module which reports to the fuel pump when to pump

otherwise check your ignition cylinder (the ignition key)

when you turn the key to "on" you should hear the pump and relay 1-2 times
if not turn off then back on several times to check



since you have been replacing so much fuel related stuff and it sat for 5 years
i would check the tank for rust
also check your fuel pressure at the distributor & WUR/CPR

[thescirocco.com]

That could be a weak fuelpump... Sometimes it's enough to run a little with the cold-start valve, but then die as soon as you open the TB. Sound familiar?

Is it a Bosch OG, or a cheapo Autozone crap?

[mainadroj]

6 pins use the fuse on the fusebox
5 pins bypass that and use fuse on the relay

5 pins are for early rabbits
6 pins are for westy rabbits/gti


and yes, the ignition controls the fuel pump
it sends a PWM signal to the igntion control module which reports to the fuel pump when to pump

otherwise check your ignition cylinder (the ignition key)

when you turn the key to "on" you should hear the pump and relay 1-2 times
if not turn off then back on several times to check



since you have been replacing so much fuel related stuff and it sat for 5 years
i would check the tank for rust
also check your fuel pressure at the distributor & WUR/CPR

I can get the pump to turn on with the jumper in. I cracked the line right where it enters the disty and it has tons of pressure, there is also bookoo pressure on the four nuts that leave the disty and head to the injectors. Yes, the car sat for 5 years, but I took off the fuel pump and soaked it in 91 octane gas for about a week, the took a small hammer and tapped on the outlet side nut, while providing 12V, and I got it to snap loose and whirrr like a top. It's the OE Bosch fuel pump. I didn't explicitly check for rust in the tank, but I took the line off and pumped the old gas into a gas can until it came out relatively clear. I can not get any noise from the pump though, with a relay. I have only been able to operate the pump with a jumper, 30 to 87. But then if I crank with just the jumper, I have no spark. I can jump the pump, with the jumper, the put the relay in, and it will run until it runs out of gas. I have also found, the pump does not run with just the jumper, it also needs the key to be on for the fuel pump to come on.

That could be a weak fuelpump... Sometimes it's enough to run a little with the cold-start valve, but then die as soon as you open the TB. Sound familiar?

Is it a Bosch OG, or a cheapo Autozone crap?

I don't have the Cold-start valve plugged in. Apparently on this car it was known to cause issues. But what I think is happening is an electrical problem. I am almost certain that I just need a relay. I had the injectors out and checked spray pattern and they look good. (soaked them in Chevron Techron for a week, then blew through them. I get good flow through them.)


The info above about the difference between 5 and 6 pins helps a lot. I think I will try a 5 pin relay and see if that does anything different. Do either of you have any suggestions on where I can get a relay?

Thank you,

Jordan

[Cushy]

My cold start valve hasnt had an issue ever. But I did buy a new one just in case. However, for your relay issue, you could have water in the relay. Afaik, the electrical side of things either work or it doesnt. But thats just from the experiences ive had.

[mainadroj]

The Bentley really is no help on this one. IIRC, it was, as someone else stated, the one on the top, 2nd from the left. Another way to identify it (once you've pulled it out), is that it has 5 pins labeled 1 15 30 31 87.

15 is the power from the ignition switch, 1 is the signal from the coil 31 is the ground, 30 is the main power, and 87 goes to the fuel pump.

There's another, similar relay, that controls the computer pins are 15 30 31 31B 87

I found this post in another thread. It says that there is a pin that comes from the coil that signals to activate the FPR. I don't have a diagram, and my relay is not labeled with a 1, but I have 3 pins on the fusebox that have ~12V when I turn the key on. One of them is a red/black wire that I've traced back from the coil. Another is a slot with two, blue/black wires, it also has 12V. The third is the center wire that I've been told is obsolete if I run a 5-pin relay with a fuse on top. I got a new relay, but the box needs to be rewired in order to make that work. I have a basic electrical understanding, but I don't about the Rabbit's wiring.

Also, my relay has the pin numbers of the above mentioned "computer relay" I have no clue what that means.

The wires to the FPR:

Tiny pin cream colored wire, ~1.4 volts with ignition on.
Two wires, same slot, blue/black ~12V with ignition on.
red/black from coil, ~12V with ignition on.
Brown from ??? ~12V with ignition on.
Black, assume it's a ground, not really sure.

All wires have no voltage with the ignition off.

Also, I have MASSIVE spark at the ignition distributor, and I checked the wires on the coil, green from pin 1 on ECU goes to coil. Same pin, red/black wire goes to FPR. I have good voltage from that pin all the way to the FPR. Also, I read something about the oil pressure relay causing problems with the fuel system. I checked voltage on the 87 pin of the oil pressure relay. There is 12V there, with the ignition on. BTW, this car does not have the remote FPR, it's right on the box.

Is there somewhere I can find a trustworthy diagram of the Fuel Pump Relay socket and what is supposed to go where. I have a new 5 pin relay with the fuse on the top. I know I have the correct socket because I can activate FP with a jumper. Also, what would a faulty ignition switch behave like?

Thanks for any help.
Jordan