LGL

Drove the 87 about 15 miles, parked for an hour and it wouldn't crank. Battery fine and I tried it several times while I waited on my tow. Several days later, it started right up. Can the start relay be intermittent ? Any troubleshooting ideas would be appreciated because I don't think AAA will be happy about towing me again any time soon.

awaino

I had a similar thing and changed out my fuel pump relay. Haven't had a problem since.

medipedicman

I would replace the ground strap at the battery if original. Has fixed several intermittent issues on different model years, for me.

Jetdriver69

I second the battery strap replacement. Such an easy fix for a lot of weird electrical problems.

Not a bad idea to have a spare fuel pump relay, AC relay, fuses, etc in the glove compartment. I have a aftermarket electric fan, so two of those relays in the glove box. Cheap insurance...

GlenL

Did it fail to turn over at all? Did the car "black out?" Was there any clicking noise?

Check:

grounds
connections at the battery.
starter relay.
starter solenoid.

LGL

It failed to turn over at all. No clicks but everything electronic functioned which pretty much eliminated battery strap which is new and tight. I don't think fuel pump relay is a possibility because it was a no crank issue, not no start. I can only see relay 14, ignition switch or ground point mpVI as possibilities but not sure if they could be intermittent.

Randy V

Did you try a jump start on the underhood hot point?

GlenL

A good list. Do the relay first.

dr bob

The starter circuit has current supplied by the ignition switch 50 terminal, through the relay coil, and through a ground path to the rear of the car that includes a connector in the spare wheel well, and on to the neutral safety switch on the side of the transmission. That safety switch is pretty robust, but the connector in the spare wheel well is subject to corrosion from battery charging fumes, and mechanical disturbances during maintenance in that area. Part of your annual electrical maintenance might be to disconnect and reseat that connector, maybe with a spritz of DeOxit while it's apart. Do the adjacent ground point too. You'll be in there to clean and treat the battery connections anyway.

The ignition switches do wear over time, and might be a suspect in your search. In reality, I think a lot of switches are swapped when the problem lies elsewhere. I know I have a perfectly good original switch in my spares bin after replacement of the original while troubleshooting something. I cleaned and bagged it.

The current from the relay to the starter solenoid passes through the 14-pin connector at front of engine bay on the right side, adjacent to the 'jump post'. Those connectors often get a little corroded, especially if the plastic shield is not present. Rain and carwash water will spill into the connector and it's just a matter of time before there are problems. Since you stated that there was no clicking, this is lower on the possibilities list. But perhaps you weren't listening for the starter relay to click or just didn't hear it. Regardless, this underhood connector should be cleaned. With battery disconnected, use a small brass detailer's toothbrush to buff off any oxidation on the connector pins. A spritz of DeOxit will help especially in the harder to clean female side.

Jim B preaches "relay-relay-relay", and I agree. Many folks suggest that you keep spares of the critcal relays in the car with you. I take that a step further and suggest that you --INSTALL-- new relays in the critical places. Maybe the starter relay should be added to that list, along with the fuel pump, injection and ignition relays. Anyway, relays are cheap in the big picture, usually ten dollars or less from our suppliers. Use Good Relays, not the off-brand ones sold at the discount stores.


So, if you go to drive the car again today and it won't start, your first action might be to make sure the transmission is securely in Park position. If that doesn't do anything, try the neutral position. Replace the starter relay prophylactically. Clean the two connectors front and rear. If the problem contines, we can get into more serious troubleshooting.

Alan

This is on the '87 - that's a manual car - so there is no safety switch in this case - but there is a direct jumper there instead - so clean that. New relay is worth installing as noted.

If the issue resurfaces do what Dr Bob proposed - wiggle the trans selector - I'd also wiggle the ignition switch around in the start position and see if that makes any difference.

Alan

soontobered84

If everything above does not work, the starter shaft could be gunky and not retracting all the way back into the starter immediately. Banging doors and hatches and hood slamming can jar it back into the correct position so that the solenoid will make the starter spin. Sometimes it can just retract slowly over time(few minutes to few hours). The fix is to clean the starter shaft while it is extended, then lubricate it so that it retracts immediately. This issue almost drove me berserk before I figured it out.

LGL

Thanks for all the help. I will work through the list, starting with a new relay and include the outcome. Of course, after I try all the logical ones, I won't know until it doesn't fail some where out of the way.

Bjbpe

Mine is also an S4 and I had intermittent start-up problems last year. It was not starter problems; mine turned out to be the fuel pump relay (in the fuse box under the dash). What I would like to suggest to anybody with what appear to be on-again, off-again problems is to take every fuse and relay out of the fuse box and diligently clean all contact faces. That would include a spray job with one of the good electronic cleaners. I hunted forever until someone on this forum suggested replacing the pump fuse and relay. Pulled them both out and they looked ok. reinserted them and the car started up. With that it was clear that there was contact resistance so I then proceeded to pull, clean and spray everything in the box. Have not had a problem in that area since.