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I removed my passager side cam cover yesterday to install Greg's new oil breather and at the same time refresh the gasket and sealing/thrust rings. After putting everything back together, the car won't start ??? It cranks fine, battery is good.
I did disconnect the battery before starting to work.
At first I thought that maybe I'd cut the Hall sender wire but after reading a post from Jim Corenman , the car will run without it. I also connected my SharkTuner since it provides a diagnostic function if there are any knock sensor or Hall sensor faults. Everything looks good
I removed a spark plug to see if there is fuel going to the cylinder. The plug was dry.
I checked the fuel pump fuse (good) and replaced it anyway. Still no start.
I changed the relays for the fuel pump, EZK and LH. Still no start.
I swapped the EZK and LH computers just to be 100% sure (I was able to connect the ST and read the data with the one already in the car). Still no start.
I will take a look a the fuel pump this afternoon or tomorrow.
Is it just a coincidence that the fuel pump died during this work or do I miss something - is there a wire/sensor on the passenger side that can be related to my no start issue?
One possibility to check:
Common for the injector wires to be deteriorated under the boots. Moving them around can short the two wires together, which stops injector operation. Move the wires around, try to straighten them. You may have to pull back the boot to check visually, if moving things around doesn't fix it.
Check for spark at the plugs. Easy to do if you have an inductive timing light. If you have spark but no fuel then injector wiring is suspect as Greg suggests. If no spark and no fuel, check the wiring/plug for the Crank Position Semsor (CPS).
The connector for the CPS is easy to disturb. If your tach doesn't bounce when you are cranking, look there. Check that the knock sensor and CPS signals aren't mixed. 3-pin Amp connectors look a bit alike.
Not common to have broken wires in loom. You might be moving the loom enough to move the crank trigger wires.
I'd go there and check out that connection.
You were right ...I continued to wiggle the loom and found that, when doing it, the wires going to injector #8 was moving also. So I started the engine and wiggle the wire of injector #8. The engine stopped. I just moved the injector connector a bit and no more issue, at least for now.
Hopefully it will continue to work until next winter. It will then be time to replace the injectors harness - after only 32 years and 260,000 kms
You were right ...I continued to wiggle the loom and found that, when doing it, the wires going to injector #8 was moving also. So I started the engine and wiggle the wire of injector #8. The engine stopped. I just moved the injector connector a bit and no more issue, at least for now.
Hopefully it will continue to work until next winter. It will then be time to replace the injectors harness - after only 32 years and 260,000 kms
Good job tracing and great that you could confirm the problem!
Figuring out this stuff can be really tough.
I've had this occur, more than just once. If it continues, pretty easy to replace that one injector end. I've got pre-wired ends with 5" of wire on them.....so you can cut back and get to "good" loom.
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
since you found the bad connection,
I would suggest you buy 10 new connectors and rewire all of the injectors and the Temp 2 sensor,
you will have one spare connector.
I solder the wire to the new terminals then rinse them with deoxit,
back fill the connectors with silicone then slide the boots on so water wont get into the plug
When I did the TB/WP and intake refresh this winter, I noticed that most (if not all) of the connectors will need to be replace including the MAF connector. This is why I am looking to replace the harness instead of rebuilding each connectors. But I am not sure that the harness is still available from Porsche...Sonnen show the part as discontinued.
Anyway I will get some connectors from Greg just in case....
I had a few dicey looking connections a few years ago and replaced them. I found that when I opened up the main run of the harness the cables were in excellent condition. The heat shrink gets rock hard and if you can, better to cut it out and replace. Same with the MAF connector and its cables. I ordered spare connectors for both the injectors and the MAF and one of these days will fit them but to date, the work I did seems to be holding up just fine.
06-09-2019, 01:07 PM
No start after cam cover gasket replacement
