Diagnose no start, Update: Need Relay board -> 74 2.0L Options

[Java2570]

I believe the AAR circuit is connected to the fuel pump power through the board....
They aren't available new but there are some on the classifieds now, one was
posted yesterday in NC. If you dig a few pages into the classifieds, someone has some real nice ones that they listed.
Bruce Stone may have one too....

[Mike Bellis]

The brake light warning circuit is active; Blinking light.

Things to check:
Switch under parking brake handle. If not pushed down all the way, it will blink

Switch (reset switch) on the brake master cylinder (under the car) it trips if fluid is low, brakes are bled or sudden loss of fluid

Most likely one of these two items. Can also be a bad diode but its rare to fail.


Relay board may be rebuildable. I have been thinking of offering this service but I haven't figured out a price or if demand is there. Part of what I used to do in the marine Corps was component level repairs. I am looking for cores. (IMG:style_emoticons/default/smile.gif)

[boxsterfan]

The brake light warning circuit is active; Blinking light.

Things to check:
Switch under parking brake handle. If not pushed down all the way, it will blink

Switch (reset switch) on the brake master cylinder (under the car) it trips if fluid is low, brakes are bled or sudden loss of fluid

Most likely one of these two items. Can also be a bad diode but its rare to fail.


Relay board may be rebuildable. I have been thinking of offering this service but I haven't figured out a price or if demand is there. Part of what I used to do in the marine Corps was component level repairs. I am looking for cores. (IMG:style_emoticons/default/smile.gif)

I've got the belly pan off, but for the life ofme, I can not find the reset switch on the brake MC. Mine is a 17mm MC.

I have looked at the switch under the e-brake and even tried pushing it in by hand with no luck. The "blinking" on/off vs the "solid on" is new.

And more fun notes: Sometimes, that ebrake light is not on (as it is supposed to be), but when that is true then the "fasten seatbelts" light is blinking and that buzzer goes off too. That's one of my favorites experiences to drive. (IMG:style_emoticons/default/confused24.gif)

[boxsterfan]

I believe the AAR circuit is connected to the fuel pump power through the board....
They aren't available new but there are some on the classifieds now, one was
posted yesterday in NC. If you dig a few pages into the classifieds, someone has some real nice ones that they listed.
Bruce Stone may have one too....

I ordered a rebuilt one from 914sixer including NOS voltage regulator. I think I saw his thread a while back also on the ones he rebuilt and they looked great.

[boxsterfan]

A follow up question about fuel pump power:

So looking at my fuel pump power problem again today, it appears my fuel pump runs continuously once the ignition is switched on (without cranking the starter) vs running only for 1.5-2.0 seconds and shutting off.

1. Given that my fuel pump has been relocated to the front, where is the most likely place that the PO jumpered in for power to the fuel pump? And most likely ground location?

2. In the original fuel pump location (engine bay) there would have been power coming off of the harness (through the snorkel?). When people relocate the pump up front, do they typically just tie up the old power lead (and ground?) for the pump in the rear?

3. If I wanted to extend the original power lead from the rear up to the fuel pump now locatced in the front, how hard is that to get through the firewall and the tunnel? Mission impossible without pulling it all out?

[Dave_Darling]

Best guess is the PO wired the pump to a switched power terminal on the fuse block--but no telling what was really done.

The power should be tied into the old power wire that's back in the engine bay. How you run it is up to you--the Doc at AA would have you drill a hole in the firewall and run a new wire that way. What I did (for other wires; I did not relocate the pump) is poke the new wires through the rubber wiring harness boot into the tunnel, and run them along side the stock wiring harness.

--DD

[Tom]

Easy test - pull the fuel pump relay on the relay board. If pumps comes on when you turn on the key switch, the PO straight wired it.
Tom

[boxsterfan]

After I replace my relay board and look for any other wiring faults, if I think my fuel pump is kaput then what are my options? I have read that there is a 2-port pump from Bosch that can be had?

[GaroldShaffer]

Sent you a PM, but before you go replacing the fuel pump you are sure the fuel filter isn't clogged?

[boxsterfan]

Sent you a PM, but before you go replacing the fuel pump you are sure the fuel filter isn't clogged?

Thanks for the PM. I'm pretty sure it is not the filter only because I don't hear the pump running when turning on the ignition. Sometimes it works (pump runs) and sometimes it doesn't).

I'm starting with the relay board (heck its 40 years old as it is) because I am also having an intermittent issue where my AAR doesn't work. It's not a stuck AAR issue...it's a power issue. After that, I'm going to triple check the wiring to the pump given that it was "hacked in" to run off of power from up front vs. running power from the rear.

I'll be honest, I'm looking at taking any of the fuel lines out from up front where the pump is dead last because I have 3/4 tank of gas. I guess my neighbors are going to get some free gas in their gas cans for their lawn mowers.

At this point, could still be anything such as bad grounds, other rotted cabling, etc, etc.... I know, I know....it will be the pump needs replaced in the end.

[Java2570]

If your fuel lines haven't been replaced, do it now while you're in there....I'm in process of doing all the lines and couldn't believe how bad my rubber lines to the tank were. One was kinked over and split all the way to the woven core; I can't believe it wasn't leaking! The SS tunnel lines are pretty easy to install and there was a minimum of swearing, which is uncommon for me! And I did get a couple of gas cans full of gas for the mower: bonus!

[Dave_Darling]

I'm starting with the relay board (heck its 40 years old as it is) because I am also having an intermittent issue where my AAR doesn't work.

The AAR runs off the fuel pump power circuit. They're connected inside the relay board. It could be something upstream of both that is causing the problem. Double-check the fuses on the relay board, and the wire that feeds power to the fuses. Wiggle the main wiring harness and see if the power drops out and comes back.

--DD

[ClayPerrine]

This should help with the fuel pump troubleshooting:


On a D-Jet car, the fuel pump will run for 2 seconds to prime the fuel ring when the key is turned on.

Troubleshooting procedure:

Get a 12V test light from FLAPS.

Hook the alligator clip on the test light to a good ground. In the engine compartment, use the battery negative post. I like to make a really long wire with a loop connector bolted to the battery negative post so I can go anywhere in the car for testing purposes. Verify you have a good test light by touching the probe to the battery positive. I learned the hard way one time to always verify the test equipment.

Go to the relay board.

Remove relay 75.

Using a test light, check to see if there is power at pin #30.

If there is no power, check for power on both sides of the rear most fuse (#91) on the relay board. It should have power on both sides. If it only has power on the right side, then you have a problem with the fuse, and you will need to remove the fuse, clean and tighten the relay board fuse contacts, and replace the fuse with a new 25 amp fuse. If the fuse is blown, and it blows again when you replace it, find the Auxiliary Air Regulator. It is on the intake plenum, on the left front side. Disconnect the white wire from it and see if the fuse blows again. If it does, then the white wire between the relay board and the Auxiliary Air Regulator is shorting to ground. I would remove the cover off the 12 pin connector at the back of the relay board and take the white wire out of it. This will disconnect the Auxiliary Air Regulator circuit. That will prevent the car from idling up when cold, so you will have to hold the throttle manually until it warms up. If the fuse does not blow with the white wire disconnected from the Auxiliary Air regulator, then the Auxiliary Air Regulator is shorted internally. You will need to source a replacement. They are NLA, so you will have to find a used one, or replace it with the L-Jet one. The L-Jet one is a different design, but performs the exact same function. You will have to add a L-Jet injector plug to connect it and you will have to ground the second lead.

If you do have power on pin #30, then use a jumper wire to connect pin #30 to pin #87. You should hear the fuel pump run.

If you do not hear the fuel pump run, leave the jumper in, and go to the pump and unplug it. Using your test light, see if one of the contacts on the fuel pump plug has power.

If you don't have power, you have an open circuit between the relay board and the fuel pump. Remove the cover off the 14 pin connector and check pin 13 (the one on the left end of the front row) with the test light. If you don't have power there, then you have a bad relay board. If you do, then you have a broken wire between the fuel pump and the relay board. The wire color is black with a yellow tracer.

If you do have power at the fuel pump, then check the ground at the pump. Move your alligator clip on the test light (or your extension wire) to the positive side of the battery. Test the other side of the fuel pump plug. If the light does not come on, then you have a bad ground. If the fuel pump is in the original rear location, it grounds at the post above the relay board. If it is a 75 or 76, where they moved the pump up front, then it grounds at the ground lug above the fuse box inside the car.

If you have a good ground, then you have a failed pump. A replacement can be obtained from FLAPS. Ask for Airtex E8445. This pump will be the correct pressure and volume, but will only have 2 fittings. If you have a 3 fitting pump, just remove the Y fitting in the line and hook the two return lines together.

[boxsterfan]

If your fuel lines haven't been replaced, do it now while you're in there....I'm in process of doing all the lines and couldn't believe how bad my rubber lines to the tank were. One was kinked over and split all the way to the woven core; I can't believe it wasn't leaking! The SS tunnel lines are pretty easy to install and there was a minimum of swearing, which is uncommon for me! And I did get a couple of gas cans full of gas for the mower: bonus!

Yes, fuel lines are SS through the tunnel.

[boxsterfan]

This should help with the fuel pump troubleshooting:


On a D-Jet car, the fuel pump will run for 2 seconds to prime the fuel ring when the key is turned on.

Troubleshooting procedure:

Get a 12V test light from FLAPS.

Hook the alligator clip on the test light to a good ground. In the engine compartment, use the battery negative post. I like to make a really long wire with a loop connector bolted to the battery negative post so I can go anywhere in the car for testing purposes. Verify you have a good test light by touching the probe to the battery positive. I learned the hard way one time to always verify the test equipment.

Go to the relay board.

Remove relay 75.

Using a test light, check to see if there is power at pin #30.

If there is no power, check for power on both sides of the rear most fuse (#91) on the relay board. It should have power on both sides. If it only has power on the right side, then you have a problem with the fuse, and you will need to remove the fuse, clean and tighten the relay board fuse contacts, and replace the fuse with a new 25 amp fuse. If the fuse is blown, and it blows again when you replace it, find the Auxiliary Air Regulator. It is on the intake plenum, on the left front side. Disconnect the white wire from it and see if the fuse blows again. If it does, then the white wire between the relay board and the Auxiliary Air Regulator is shorting to ground. I would remove the cover off the 12 pin connector at the back of the relay board and take the white wire out of it. This will disconnect the Auxiliary Air Regulator circuit. That will prevent the car from idling up when cold, so you will have to hold the throttle manually until it warms up. If the fuse does not blow with the white wire disconnected from the Auxiliary Air regulator, then the Auxiliary Air Regulator is shorted internally. You will need to source a replacement. They are NLA, so you will have to find a used one, or replace it with the L-Jet one. The L-Jet one is a different design, but performs the exact same function. You will have to add a L-Jet injector plug to connect it and you will have to ground the second lead.

If you do have power on pin #30, then use a jumper wire to connect pin #30 to pin #87. You should hear the fuel pump run.

If you do not hear the fuel pump run, leave the jumper in, and go to the pump and unplug it. Using your test light, see if one of the contacts on the fuel pump plug has power.

If you don't have power, you have an open circuit between the relay board and the fuel pump. Remove the cover off the 14 pin connector and check pin 13 (the one on the left end of the front row) with the test light. If you don't have power there, then you have a bad relay board. If you do, then you have a broken wire between the fuel pump and the relay board. The wire color is black with a yellow tracer.

If you do have power at the fuel pump, then check the ground at the pump. Move your alligator clip on the test light (or your extension wire) to the positive side of the battery. Test the other side of the fuel pump plug. If the light does not come on, then you have a bad ground. If the fuel pump is in the original rear location, it grounds at the post above the relay board. If it is a 75 or 76, where they moved the pump up front, then it grounds at the ground lug above the fuse box inside the car.

If you have a good ground, then you have a failed pump. A replacement can be obtained from FLAPS. Ask for Airtex E8445. This pump will be the correct pressure and volume, but will only have 2 fittings. If you have a 3 fitting pump, just remove the Y fitting in the line and hook the two return lines together.

I'm selling the car if I can't fix it with that info. (IMG:style_emoticons/default/beer3.gif) Thanks!