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Posted by: Dave97 May 19 2024, 03:12 PM

Do relay boards have intermittent problems? I’m having problems with the fuel pump. I lose power to the pump. Switch relays on the side of the road no go. Get home check power at the fuse ok, take a headlight relay, powers right up. Could I have a bad board connection? Intermittent? Thanks. Dave

Posted by: Shivers May 19 2024, 03:35 PM

Yes it can. On the bottom as well as the sockets. The copper can crack or the open end rivits can come loose

Posted by: bdstone914 May 20 2024, 10:00 PM

@http://www.914world.com/bbs2/index.php?showuser=21285

Test all fuel pump leads on the relay board.

http://www.914world.com/bbs2/index.php?showtopic=351033

From the 14 pin connector from fuse, from relay and the 12 pin connector.
I have not found relay board problems to be common or intermittent.
Even loose terminals at the fuel pump can cause your problem.

Posted by: second wind May 20 2024, 10:52 PM

Hello Dave97.....I chased this problem on my '73 2.0 for weeks and replaced/ and or addressed 13 different issues.....I truly think replacing the wiring harness did the trick....they get in such bad shape over 50 years I was so happy to get a new one in there and wala !!! Car runs great....the other steps didn't hurt either including replacing the relay board but the harness was the root culprit imho.....good luck!!
gg

Posted by: dr914@autoatlanta.com May 21 2024, 10:44 AM

we clean and re solder connections but find very few problems with them unless people put heavy fuses in the holders and melt the holder

Posted by: Ishley May 21 2024, 12:44 PM

On my 72 it turned out to be the ECU. Replaced it and it all works good now.

Posted by: Dave97 May 21 2024, 09:30 PM

Thanks everyone. The challenge has been it is intermittent. It has stranded me twice. I can be driving along, then no fuel pump..I’m running webers I also run a ground wire from the spade connector on the board. The intermittent part makes it difficult because I have tested the wiring , pulled the gas tank then, checked power at the fuses, changed the relays around and then it works. I drive about 1;000 miles, then no power to the pump. That’s why I asked if there could be a loose connection at the relay pins or at the fuses.
What do I use to get the “tar” off the bottom to check? What do,I use to replace it when I’m done? Thanks again everyone. Dave

Posted by: bdstone914 May 22 2024, 07:56 AM

Test it first. Mist are good. I did have one recently that had no continuity on pin one. Connection to the trace was good.
Put the whole board in boiling water for about five minutes. I use Flexseal to reseal them. Or silicone tubber. First seal the alternator cinnections with silicine ir the Flexseal will flow into the socket. Use a rubber eraser to pkug the square hole.

Out the whole relay board in boiling water to soften the tar. Scr

Posted by: Ishley May 22 2024, 11:02 AM

What year is it? On the earlier cars the original fuel pump was in the rear. The positive wire ran along the fie wall and terminated near the ECU/Battery. When I had issues... I made up a length of jumper wire to plug into that wire and I plugged the other end into a multi prong connector on the coil. When you turn the key the pump ran... but it got me home a few times until I figured out the issue.

Posted by: mepstein May 22 2024, 11:14 AM

I had an early car with a fuel pump problem that was really a relay board problem. Switched it out and the car started right up. They are 50 years old.

Posted by: 930cabman May 22 2024, 11:29 AM

Many of us at 50 y/o can barely start at all

Posted by: JamesM May 22 2024, 05:06 PM

They can fail in multiple places that will impact the fuel pump and I have seen them with intermittent failure issues. Last one I fixed was one of the hardest ones I have had to track down and was very intermittent. Issue on that one was at the 4 pin connector to the injection system, weak connection at solder joint for the fuel pump relay trigger wire. It would test out fine when the connector was not on it but with the 4 pin connector installed it stressed the joint enough to intermittently loose connection. I have had other that failed at the relay socket itself. Old relay boards with no availability for new replacements is probably the biggest headache I have with keeping d-jet going these days. (this surpassed old worn out distributors when the 123dizzy became available)

Posted by: JamesM May 22 2024, 05:10 PM

Thats funny. I think I have about 7 spares and every single one of them has failed in a different way, though on the bench they usually trace out ok.

Posted by: bkrantz May 22 2024, 08:54 PM

Well, scrape the crud off your bottom and re-solder your connections.

Posted by: HaraldD May 23 2024, 10:44 AM

Hello Dave,
maybe you have problems with your pins / connectors in the plug to the relay board.
Some years ago I want to start my engine - and no sound from the pump.
But at that time I stay by the pre owner of #40.
And a friend of him tell me to take a "Cutter Knife" and put in the connectors from above, so you bend them outwards. The connector loses contact in all these years.
Problem solved!

Harald