hchc

Well here's my first time. Cruising to a stop sign, engine dies, all lights on. Tried to start again engine would turnover but would not start. OK, thinking that's what my spare DME relay is for. Nope, swapped in the new DME relay still would not start. All belts checked. Ironic thing is I'm just couple of blocks away from my home Got it towed back to garage anyway.

Swapped starter relay, nope. Unplug/replug battery to reset everything, nope.
Checked all fuses, all are good. Tried to see if there is any outstanding code using the gas pedal (its a 95 obd1). Here is the weird thing, I used to be able to do that using the gas pedal, but now its doesn't work anymore. The engine light would stay on and not flash even once no matter how hard or long I press on the gas pedal. Does it mean that the ECU is fried? I just put in a GIAC chip few weeks ago btw.

Another possible symptom is that I started smelling gas inside the cabin through the vent on acceleration just starting today. I thought there might be problem with the fuel pump or fuel line leak. Maybe the fuel pump has seized? But I think that would fried the fuel pump fuse as well?

I'm going to check for spark, swap back in the stock chip, and check the fuel pump next.
Any more ideas?

MarkD

swapping back to the stock chip is a great idea, based on your description

ChaseN

Depending on failure mode, it might not...I fried my 964 fuel pump a few years ago by running it out of gas (long story, it was late, I had to GO, and I tried to stretch it home...) and I didn't have to replace the fuse.
I'm not sure how smelling gas in the vents would relate to single-point fuel pump failure, though...

goofballdeluxe

Engine dying and all the lights coming on like a Christmas tree sounds like maybe you could be having trouble with your alternator perhaps?

hchc

So I jumped pin 3 and 7 of the DME relay socket and hear the fuel pump whirring so I think the fuel pump is fine (haven't check the fuel pressure port thou without the proper gauge and connection)

Next is to hook up a timing light and look for spark. And no spark while cranking! This car just have and new cap and rotor, plug and wires about 500 miles ago and has been fine since the change. Why would the spark suddenly stop while the engine is running?
Would it be the ECU itself, the coils, the speed reference sensor? Any other ideas?

I checked the voltage at the battery last week while the car is running and its at 14.2v, not ideal but there should be enough juice. Also getting a reading of 13.9v from the cigarette socket while the car is running.

IXLR8

That 14.2V is fine.

IXLR8

Is the electrical connector at the side of the distributor firmly seated?

993James993

Does the car start and run now?

element

I had a similar issue.. there was a loose wire and issues with the DME. Dealership got it running, but I still have issues reading codes which I need to troubleshoot - it runs fine now.

PWIS FAULT CK-NO COMMUNICATION TO DME-TECH HAD TO PIN-OUT CK DME PWER SUPPLY RELAY-NO 30 POWER TO RELAY-CK 30 POWER FUSE #47-NO POER-TRACE OUT POWER LOSS TO BATTERY-MAIN CONNECTION MOUNTING NUT LOOSE. NOT MAIN WIRRING POWER SUPPLY CABLE-THE LITTLE WIRE TO THE BATTERY,RE-CK SYSTEM-TEST DRIVE OKAY AT THIS TIME.

NOTE-DME WILL NOT COMMUNICATE WITH OUR SOFTWARE AND NOTICED WHILE DRIVING VEHICLE IDLE IS UNSTABLE AT TIMES BUT CAR RUNS GOOD

Slow Guy

This.

hchc

Yes its connected. Thanks for the suggestion. I also check all the connector and hose connection I can visually check.

Nope. Try to start this morning to see if cold or warm engine makes a difference. Still turnover but no start.

Yes. I'm going to do that next. But wondering how would a chip suddenly fails? I hope I don't need new Motronic ECU...I guess I'll give Steve W. a call.
Since I have install the GIAC chip, the engine has missed (engines light flashes) and shut off while running a couple times, but both times it started right back up.

techman1

If the main connector under the seat for the motronic comes off, would it still crank? Wondering if the shop that did the ecu swap did not fully seat the connector.

Steve Weiner-Rennsport Systems

Call me!!!

Its possible that the encrypting socket is bad and if thats the case, I'll send you a new one.

Slow Guy

Curious what an "encripting socket" is?

hchc

AFAIK, the code on the GIAC chip is encrypted to prevent copying/tampering with. So there is an extra layer of adapter that sits between the chip and the ecu board to decrypt the code for motronics consumption. I hope thats where the problem is and will isolate tonite.