Engine died after hitting potholes

[brian52555]

Driving home from work, I hit a bunch of potholes in downtown SF. The car first cut power for a split second (note that headlights, dash lights were still working), and threw a check engine light. The car drove normally for another block before completely dying. It would crank but the motor wouldn't 'catch'.

The car is very stiff with 600/700 lb spring rates front and rear, and urethane everything. I don't usually commute in the car but I had no other car to drive this past weekend.

My guess is that something electrical popped out of place? Unfortunately, this has happened to me before- that time it turned out that the relays had bounced out of their holders. This time, I checked all the relays, fuses, and battery connection - all were fine.

Anyways, I ended up having the car towed to my mechanics shop... where it started right up. I drove it into his garage in fact. Any ideas what the problem could be? A ground that's been knocked out of place? Thanks.

[nando]

is your main relay original?

[brian52555]

Very likely. It looks really old.

[brian52555]

I mean, relays don't just fail and then work again later though?

[nando]

yes, yes they do. :(

[Vivek]

Completely OT, but doesn't SF have a law that the city is responsible for damages caused to your car by the roads? May be complete BS but I heard that somewhere.

[5Toes]

Main engine ground??

[nrubenstein]

Start by making sure the relays are fully seated.

[brian52555]

Yep, I check that all the relays were seated when I was stalled by the side of the road. That's what happened to me previously when I was driving back from Ryan G's shop after getting my urethane subframe bushings put in.

I THINK the main engine ground cable is ok. I checked it recently-ish.

[Vtec?lol]

Check the crank sensor?

[E30_fiend]

99% sure its your main relay. A friend of mine had that problem on his trip home last summer. Then we had the very same problem on the drive back to seattle. His main relay for one, had never been replaced, and two, the relay didn't sit very snug in the connector.

Solution:
New relay and we got a 12" zip tie and wrapped it over the top and underneath the connector them zipped it down. Hasn't had a problem in 4 months. And he daily drives it as well.

Hope that helps


Taylor

[FLG]

Had this happen to me a few days ago, not sure if me and Taylor are referring to the same relay, but the one that popped out for me is one on the bunch that sit a bit up further from the fuse box and have that plastic cover over them.

Also, check the crank sensor as well, since you stated the relays were fully seated.

[francogt1]

deferentially electrical

[E30_fiend]

Had this happen to me a few days ago, not sure if me and Taylor are referring to the same relay, but the one that popped out for me is one on the bunch that sit a bit up further from the fuse box and have that plastic cover over them.

Yep, that's the one. It's the main relay

[brian52555]

Thanks guys. Yep, after they popped out last time I zip tied them in. It's very possible they are dead or dying. I'll check into that and the other things mentioned in this thread. Thanks!