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Discussion Starter #1
Hopefully the long post will not scare away the pros but i want to be as detailed as possible...

Background--might be related to the issue i have now but maybe not..

Starting about 2 weeks ago when i went out to start my car in the morning i would have to crank the engine for 1-20 seconds before it would start. Thinking that maybe fuel pump going out and all the fuel would drain back into the tank overnight(car parked in driveway with front higher than rear).

Driving home and car would hesitate if i gave it more than half throttle would sound like i had turned the key off while still moving in gear until i let off the pedal about half way then it would run fine. I operated this way for about a mile and then just stopped running. no backfires, engine just stopped.

I subscribe to alldata so after looking at electrical diagrams i decided that the cheapest quickest stab at this would be the fuel pump relay. Relay replaced and still have same issue.

Fuse 15 Engine Electronics-good
Fuse 18 Fuel Pump-good

Fuel Pump relay removed and jumpered pin 30 to pin 87 and i can hear the fuel pump run. With fuel pump running (jumpered) car still will not start.

Checked impedance of all the legs on the coil and they are within specs, pulled the coil wire from the distributor cap, inserted meter and see no VDC reading on multimeter when car is cranked.

From my understanding of the schematics and from my reading, the ECM provides a temporary ground from pin 6 of the ECU to pin 85 of the fuel pump relay. continuity is good from the ECM plug all the way to the fuel pump relay pin 85. Since my Fuel Pump will run with the jumper placed in relay slot i know that the wiring is good from the relay panel to the pump.

I am at this point looking at the ECM. Purchased a used one online. Disconnected the battery, installed the "new" one, reconnected the battery and still have the same issue. While i do understand there is a possibility that the used ECM is shot I have not accepted that since I have the same exact issue.


MY SPECULATION:
I believe that the ECM provides the ground to the FP relay just long enough to prime the cylinders and start the engine. Once the engine is running the ECM will continue to place a ground on this line as long as it receives good reports from some sensors (maybe MAS, O2, Fuel Pressure, Evap....) i could understand if the car would start and then die due to a bad sensor input to the ECM but i cant even get that far.

I think that there is something that is keeping the ECM from possibly "turning on" but cannot find a good ECM pinout to tell what is an input signal and what is coming out of the ECM. Based on the fact that I do not believe i have spark either I also speculate that I do not have a control ground from ECM pin 8 to the coil.

I have seen on a few different threads where people were talking of the ignition switch or possibly the camshaft position sensor???


Any input is greatly appreciated

Eric
98 VW Cabrio MK3 A Engine 2.0L Manual
When it first happened i got a code that read Fuel Pump Electrical Circuit failure but nothing since..
 

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Discussion Starter #2
UPDATE-

After hours of searching threads and tracing wires throughout my wire harness a hard lesson was learned. FAILED IGNITION COIL

Even though i the resistance measurements across the primary and secondary were well within specs the coil was bad. purchased a new one last night and installed it. Car started right up. Put my original ECM back in and good to go!
 
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