Jackson911

I have a '97 C2S with 58K miles and I could use some help determining the cause of my issue. The car has been driving well with no issues until about three weeks ago. I was leaving my neighborhood and turned right from a complete stop. The car hesitated and seemed to lose power, then regained power, and ran fine for the errands (no check engine light or other lights on dash appeared). I returned home for about an hour, then went to start the car again and it struggled to start, and all the lights on the dash came on. I sat there for a few minutes, tried again, it struggled, but started up (no check engine or other lights on dash appeared). I pulled car back into garage and decided to do some research here. I decided to order a Focus 9 DME relay and replaced it last week.

Since then, the car has been running perfectly until this morning. I made several errands with no issues until my last stop where I had a difficulty with starting the car again (same scenario as above). It struggled to start on the second attempt, but finally did. Then I drove through the parking lot and it seemed to lose power again. I pulled into a parking spot and it seemed to idle fine, and once I got on the road, I was able to make it home with no issues. If something is failing, I'd like to figure it out prior to being stuck somewhere.

Hopefully my description is clear enough to get some thoughts?

C4SJOHN

Jackson 911, years ago I had small issues like yours on my C4S 993 and It turn out to be a battery grounding cable going bad. I replace the cable and clean up the contact areas, problem gone. Good luck.

PRSWILL

Could also be the infamous DME relay. Try plugging in a spare if you have one..

fatmike

I would start with blaming the DME relay. Just because it's new doesn't mean it works.

How old are you spark plug wires? Was it wet/raining when this happened? Can you visually inspect them - especially the bottom bank.

I agree look at the ground (s). I clean them anytime I'm working on the car and near one. Have you done maintenance on the electrical system of the engine (Distributor caps, rotors, coils, etc.)?

/

crw

Also, check your fuse box where the DME plugs in - sometimes there can be a problem where the DME plugs in - look to see if the plastic shows any signs of melting.

Jackson911

Thanks, I will check the grounding cable and look to replace

Thanks - I need to order another new one as a back-up so I'll do that today
Not sure not the spark plug wires, I'll check my records. I did hand wash the car an hour or so prior and dried with a blower prior to the first power loss, but today it was completely dry.
I have not done any work on the electrical system

71-3.0-911

How loud is your fuel pump?

Have you already replaced the DME and it ran better? This feels like a fuel pump and is exhibiting the same behavior that mine did. At about 95k, fuel pump became loud, blew DME, replaced DME, limped home, replaced fuel pump and F9 solid state relay, never another problem.

Jackson911

Yes, replaced DME with F9 solid state last week and car was running well until the issue this morning. The fuel pump is not loud at all

pp000830

I would put a fresh standard DME relay in and see if your problem goes away.
Andy

IainM

Problem with intermittent problems is it’s impossible to diagnose unless it’s happening. Strategy 1 is start throwing parts at it and if done sensibly, starting with plausible systems that need replacing anyway, is a reasonable way to go.
Strategy 2 is counterintuitive: drive the car more until the intermittent part fails. Daily driving will likely flush the bug out in short order. Just make sure you’re carrying your AAA card.

rk-d

Initially it sounded like a bad gas story.

Maybe the fuel pump, if the problem is persisting.

Mfbuehler

I had a similar issue last year (sluggish starts when the engine was hot) and I suspected the fuel system after I replaced the DME. In my case I also had an occasional low idle stall when hot. I replaced the fuel filter because I couldn’t get a sense of when it was last done. I have had no issues since then.

sacman

I would check the fuel pump. The Focus9 DME is a solid state and it's new so the likelyhood of it being the problem again is low. If you got the version that prime the pump then every time you restart the car it should get the fuel in the system unless your fuel pump is on the verge of failing. Check your fuel pressure with a guage and definitely check the ground strap.

Jackson911

Thanks for all of the input. I've ordered another new F9 relay and will also check the following: battery ground cable, fuse box (as mentioned above), and fuel filter. The good news, or possibly bad news, is that I drive this multiple times a week so we will see what happens.

I appreciate the input and I'll report back on my progress.

Thanks, Evan

Jackson911

The battery cable and other misc items I ordered arrived. I changed the cable this morning, but left the new F9 DME relay in place so I could attempt to narrow down the issue. The car started up and drove with no issues this afternoon.

I couldn’t really see the existing cable as it’s under the cd changer, but this is what it looks like. I assume it is original and hopefully is the primary cause of my issue

I appreciate the help.