How do relays fail?

Well, the filter didn't fix it. Still feels like fuel starvation. Died twice on a 5min trip. Is there such a thing as an intermittent relay failure, or do they just go all at once?

Yes, they can fail intermittently. I had one in my BMW that counfounded me for a year before I figured out it was bad...it would work, but only 90% of the time.

A relay is a lot like a breaker and each time the relay clicks there is a small arc of electricity between the contacts, after awhile the electrical arcing will cause corrosion which builds up and prevents contact.

Another way they can fail is the solder joints can fail. I've read about people resoldering the joints and cleaning the contacts and making a relay live again. Most people don't go through the effort to repair something easily bought though.

This is why a standard fix on relays it to give them a thump! Electrical problems and physical motion combined with heat and arcing...

Sometimes it gets wonky first, then it quits.

Bruce

The '80's 2.2 Mopars I've played with have auto-shutdown relays. They do fail, but still do their function. The car auto-shuts down. When you don't want it to.

This may be helpful:

http://www.dietersmotorsports.com/tech/2001/DME_relay_failure.htm

Thanks, guys. I think I'll swap it with the one from the green C. Seriously hoping it's not the pump, I haven't found work yet.

Should be cheap enough to just throw in there. They tend to fail more when warm/hot, so it would make sense that your car would start and then shut down shortly after.

Cone_Junky wrote: Should be cheap enough to just throw in there. They tend to fail more when warm/hot, so it would make sense that your car would start and then shut down shortly after.

Odd thing--after thinking about it, seems like it did worse when it was cold. It cut off twice on the way to the store, and then ran OK on the way back (I'm thinking of heat soak while it was shut down at the store). Could it be heat expansion of all the little metal bits inside? I'm going to just swap out the relay with the one from the green C. Of course, that one's 20yrs old as well. I see new ones at Rock Auto for less than $10. One of them is even less than $5, but the "info" button won't tell me whether or not the thing was made in China.

"Berkelying relays! How do they work!"

Do the fuel pump relay, ecu (109), crank sensor and the ignition switch. All are probably bad or will be soon in an slc.

Relays in British cars always work intermittently.

benzbaronDaryn wrote: A relay is a lot like a breaker and each time the relay clicks there is a small arc of electricity between the contacts, after awhile the electrical arcing will cause corrosion which builds up and prevents contact. Another way they can fail is the solder joints can fail. I've read about people resoldering the joints and cleaning the contacts and making a relay live again. Most people don't go through the effort to repair something easily bought though.

Also, sometimes that corrosion builds up and prevents the relay from breaking contact.

Paul_VR6 wrote: Do the fuel pump relay, ecu (109), crank sensor and the ignition switch. All are probably bad or will be soon in an slc.

If I still have a tach, does that mean the crank sensor can wait? And I'd have to go back through the service records, but I think the PO got the switch done.

I have seen relays which would get 'weak' over time, the electromagnet pulls the 'bar' but with very little force. Dunno why, but yeah it has happened. The burnt contacts are common, I have also seen the little tiny copper wire for the windings break on one old Lucas relay. I pulled about a turn off the electromagnet and soldered it back to its terminal and it worked.

OBTW: check the terminals in the terminal block carefully. Back in da day Ford had a TERRIBLE problem with terminals which would get hot and relax their grip on the male relay terminals, leading to all kinds of goofy problems, mostly with ECM and fuel pump relays. IIRC they sourced all that stuff from Bosch and Delphi, which, you guessed it, are two big VW suppliers.

friedgreencorrado wrote: Well, the filter didn't fix it. Still feels like fuel starvation. Died twice on a 5min trip. Is there such a thing as an intermittent relay failure, or do they just go all at once?

Your problem is EXACTLY identical to the problem SWMBO had with her '92 Jetta. Turned out to be a bad relay. It would run and run and run then completely randomly die, sometimes more frequently than others.

I went to the VW dealer for a new one (price was not that much more than online). Turns out that VW had superseded the original relay design - TWICE. I don't know if I would trust the aftermarket to have cloned VW's design improvements.

I would be surprised if your Corrado, being from the same era, does not have the exact same poorly designed relay causing problems.

FWIW if I was out of work, a Corrado would NOT be my vehicle of choice. I sold my stick E34 touring less than a week after the one and only time I got sh*tcanned and bought a $400 Subaru wagon. It sucked, but knowing I wasn't about to go broke over fixing a complicated car with zero income, and getting some cash in my pocket was more than worth the trade. I'm sure you have your reasons, and I'm not trying to tell you how to live your life by any means - just a suggestion from someone who's been there.

SlickDizzy wrote: FWIW if I was out of work, a Corrado would NOT be my vehicle of choice. I sold my stick E34 touring less than a week after the one and only time I got sh*tcanned and bought a $400 Subaru wagon. It sucked, but knowing I wasn't about to go broke over fixing a complicated car with zero income, and getting some cash in my pocket was more than worth the trade. I'm sure you have your reasons, and I'm not trying to tell you how to live your life by any means - just a suggestion from someone who's been there.

I'm not offended in the least. In fact, I've been having similar thoughts myself. Really tempted to sell all three right now and buy something newer and Japanese. I just know that I'll never forgive myself if I get back on my feet sooner rather than later. It's definitely a possibility, though. I suppose I'm saving it for a last-minute desperation move, I'll be able to rationalize it better if things get that bad.

I'll never forgive myself

Exactly. Now GET OFF THE COMPUTER, SHUTDOWN THE XBOX, FIX THE CAR, AND GO FIND A JOB, HIPPY!

In reply to poopshovel:

Actually, my hair's driving me nuts. Didn't realize it was getting so long until I was under the car last weekend.

If you jumper fp and ecu relays is it fine all the time?

If you have tach crank signal the crank sensor is likely intermittently working right now. ;)

In reply to Paul_VR6:

Of course. If I had no tach it wouldn't start in the first place. Jeez, it's like I've forgotten every thing I ever knew..

Didn't jump the relays, just plugged in the ones from the other car.

You can have crank signal but no ecu power and the tach wont work.

Cel illuminate with key on every time? Or is yours pre "engine running" light?

In reply to Paul_VR6:

Pre-light. 1992 OBD I. Dizzy, too.

Damn tough one to diagnose!

In reply to Paul_VR6:

I'm betting you're right about the crank sensor. If you're not right, it almost has to be the pump. For now, I think I'm actually going to put the relays back into the green C and mount the good tires on it as well. It has some cooling fan speed problems (at the moment, either high speed or nothing), but I think that might go away if I clean all the wiring connectors. Even if that doesn't work, hey..in a Southern summer, the fans would probably be running full speed anyway.

I know the green one hasn't had ignition switch done yet, but last time I used it as a DD it didn't die in the middle of the street more than once or twice a month.

Paul, seriously..thanks, man. Don't forget your diagnosis over the interwebz was better than mine while I could actually touch the stupid car..

No problem. One more quickie on the crank sensor: clean connector contacts and also pull sensor from the block and check/clean any debris from it. Think of it as a factory installed magnetic drain plug.