Getting very frustrated

Waddy · 09-16-2009, 10:54 AM

I have been a long time lurker and I appreciate all of the valuable info I have gotten from this site. This is my first post. I will try to keep this short. I have an 89 930 with 18,000+ miles that I have had for 3 years. About a year after I purchased it, it left me stranded on the highway, my mechanic said it was the fuel pump relay so it was replaced. 10 miles later got stranded again. Again a fuel pump relay. So I replaced both of them and all seemed well. 500 miles later stranded again so I changed all of the red relays in front and the red and yellow in the rear. Ran fine for 15 miles last weekend then stalled again (in my driveway fortunately). I pulled and re-installed all of the relays and got it cranked again and began to try to trouble shoot the electrical issue with the engine running. When I wiggled two wires (they are actually plugs-see pic) just ahead of the red relay in the engine bay the engine sputtered and stalled. I have not been able to restart it. I guess this could be the culprit. Below is a pic of the two wires and plugs. One is a single pin plug and the other is a triple pin plug. See pic below. So I have 2 questions. Can anyone tell me what these plug wires do and do you think it could be the cause? Anyone know a good electrical mechanic in the Atlanta area?
Thanks!

zaman fu · 09-16-2009, 11:19 AM

I think your car is worried about cracking 20,000 miles.

full quack · 09-16-2009, 11:26 AM

Yes, age is no friend to electrical wires, they dry out & crack, leading to shorts or opens.
I find it curious that your car with 18K on it, already has an aftermarket Permatune C.D.I. box on it. Hummmmm.
Mark

Waddy · 09-16-2009, 12:47 PM

I would love to get over 20k if I could get to where I trust it. Regarding the permatune it was there when I bought the car so I have no clue when, or why, it was installed. Could it be the culprit? I guess I just need to get it to a good mechanic.

Thanks

A930Rocket · 09-16-2009, 12:54 PM

I want to say the one wire is the tach wire. Is it black with a purple stripe? The three wire I think is the O2 sensor wire.

You might be pulling on the wires and doing something to the Permatune or the mount that holds the fuses and relay.

With the Permatune, I don't know if it whines like a stock CDI box with the ignition on.

Are you getting any spark? Pull the center coil wire to find out. If you have fire, then you need to look at fuel. Do you hear the pumps running?

Where in Atlanta are you?

Waddy · 09-16-2009, 12:55 PM

Obligatory pic.

A930Rocket · 09-16-2009, 12:57 PM

BTW. The car should run with either wire unplugged.

mark houghton · 09-16-2009, 01:02 PM

Do the '89's also have the funky yellow over-boost fuel pump cut out relay? Could also be a bad connection there, or a bad relay itself.
Need to determine if it's lack of spark shutting you down, or lack of fuel. When this happens, can you force the pumps to run either by pushing down on the metering plate, or pulling the blue connector behind the top side of the fuel head?

timc · 09-16-2009, 03:25 PM

I know your issue sounds more like a wiring problem, but just to rule it out, if you call permatune, which I did several years ago, they will provide you with a very simple test to confirm the correct operation of the permatune.

Benny771 · Benny771's Garage

Im leaning towards fuel pump.
It all started there it seems.

DDDD · 09-16-2009, 04:13 PM

Quote:

Originally Posted by timc

I know your issue sounds more like a wiring problem, but just to rule it out, if you call permatune, which I did several years ago, they will provide you with a very simple test to confirm the correct operation of the permatune.

I would definitely check your permatune if other ideas don't pan out. Those units can overheat sometimes. Not saying that is the problem.

Jim2 · Jim2's Garage

"my mechanic said it was the fuel pump relay so it was replaced"

"Again a fuel pump relay. So I replaced both of them"

Likely not both fuel pump relays, but just one. Can you narrow it down by replacing ONE relay at a time. That suspect fuel pump is probably pulling too much current though I'd expect the associated fuse to blow.

Probably just a loose plug at the rear. Ensure they are all tight together, and feel under the permatune and try to push the plug upwards.

Nice car!

full quack · 09-16-2009, 05:58 PM

When my Permatune CDI box crapped out, it first died once while idling. So I did the usual checks on relays, wire, etc. found nothing. By this time 20 minutes had past. The car fired right up. That lasted for 2 miles, once again poked & prodded for another 20 minutes, found nothing enlightening, but once again the car fired right up, drove 1 mile, died again. Waited for the tow truck, and this time it fired up just long enough to get lined up for the tow truck.
So it appears these thing start to overheat when they are giving up the ghost. So they do the over heat-die-over heat-die dance.
I now have a rebuilt Bosch unit, and it has been running flawless for 30K miles.
But like everybody else is saying, could be broken wires, bad relay, dying pump.
And yes, the Permatune unit should "whine" if it's working correctly.
Mark

JFairman · 09-16-2009, 06:30 PM

Permatune CD ignitions don't whine at all.
I know, I have one and a friend does too.

I had a mallory "Super CD" ignition that i moved from car to car many years ago. It whined and drove me nuts because it would come through the cassette deck while listening to music and nothing could stop it... this was 20-30 years ago.

The CD whine is alot like the thermistor whine charging in a battery powered electronic flash unit. They are CD also.

zaman fu · 09-16-2009, 09:55 PM

your car is beautiful. i have the same color. metallic silver/black interior.

beepbeep · 09-17-2009, 02:15 AM

There are two fuel pumps. Are they whining when car doesn't want to start? If yes: you have issue with something else. If no: there is electrical problem with fuel pumps. If you already changed relays, I suggest checking overboost switch. It's wired to cut both fuel pumps in case of overboost. If it looses connection to ground, both will stop. It might be corroded connection.

xbmwguy · xbmwguy's Garage

+1 on the overboost switch its the yellow guy in engine bay. have someone try and start car while you lightly twist on yellow reay. these are prone to internal solder failure

xbmwguy · xbmwguy's Garage

oh and i am partial to your car

pavulon · 09-17-2009, 03:21 AM

If any of the folks w/ '89 930 coupes are considering selling, I'd very much like to talk to them...I've been looking for a long time. Thanks.

Waddy · 09-17-2009, 05:23 AM

I appreciate all of the feedback. It is very helpful. Full Quack: your problems sound very similar to mine. A few times after it died on me it would start up after a 30 min to 1 hr rest. But not all of the time. I can not hear the whine of the fuel pumps nor the Permatune. I have changed the yellow overboost relay in the back recently and tried to wiggle it when someone else was cranking. That diddnt do it. Thanks again. I'll let you know how it turns out.