Tom Loder

I'm hoping the Rennlist wisdom panel can help me start to troubleshoot a problem with my 944S2 stalling. Both happened while my wife was driving her car without me, so I'm relaying the symptoms she described. I have not been able to reproduce them.

Symptoms

1. She came to a stop and the car stalled. The ! warninglight came on along with Anti-lock light. She was able to restart by thumping the fuse box. Also, she thought the car became very hard to steer after that as if power steering went out. I drove the car the next day and again a few days later and experienced no issues.
2. A few weeks later, the car stalled while pulling into a parking spot and was able to restart using the thump method, but then wouldn't stay running unless she was giving it gas. It stalled again. went to swap cars and thumped the fusebox and it started right up and drove fine 2 miles home.

In both cases, she doesn't believe the RPMs stumbled or were too low and that caused the car to stall, but isn't 100% sure. She felt the engine just turned off.

Additionally, I have sometimes felt the car idle low/rough when stopped.

I would suspect the DME relay, but the fact that she could keep it running by giving gas would indicate the relay is still working and pumping fuel to the engine.


Note: The technique of giving a few hard thumps on the fuse box, was conveyed to me by the previous owner, and usually will allow the car to start again while hot. This doesn't need to be done cold. I have replaced the DME relay with a URO model from Amazon. It has not removed the need to thump the fuse box to get the car to start when it's hot occasionally. Sometimes it starts without issue, sometimes it needs motivation.

Zirconocene

If you think it's the DME I'd strongly suggest going to a solid state relay (no affiliation: http://www.ftech9.com/new-products?c...d-State+Relays) ). I haven't had any issues with my DME ('91 S2 coupe) but I bought one anyway given the historical issues that people have had with this part. The reliability that people report on these threads indicate that it's a solid product.

These problems solved by percussive therapy always worry me because it's typically something really hard to see/find.

Good luck!

Tom Loder

I'm not sure it's the relay because it kept running when she gave it gas. I thought the DME relay powered the fuel pump as well.

I've been thinking about the Ftech model for a while now. On sale right now so it can't hurt to try it.

jhowell371

Beating on something shouldn't be part of a normal hot start routine, do it once to get you running and home but then it's a problem to be addressed. I think you have a bad connection in the fuse box. The harness connections to the fuse box can become loose or corroded. Fuel or mechanical problems don't respond to a whack. YMMV

Jfrahm

Easy enough to try a shot of starting fluid when it won't start, to see if it needs fuel.

Tom Loder

I know, it's on my list of things to look into. I'm going to try the solid state relay before I dig into the wiring harness.