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-   -   993 not starting after trans rebuild / engine out - no spark, no fuel (http://forums.pelicanparts.com/porsche-964-993-technical-forum/679052-993-not-starting-after-trans-rebuild-engine-out-no-spark-no-fuel.html)

aigel 05-20-2012 07:05 PM

993 not starting after trans rebuild / engine out - no spark, no fuel
 
Well, that was pretty anti-climatctic. Worked all weekend putting the car back together and just turned the key. Cranks over great but doesn't start.

What I checked:

- Spark when cranking - none
- Fuel smell - none
- Fuel line disconnect at engine - no fuel
- DME / fuel pump relay - checked on bench - works okay, makes contact for both solenoids
- Can't hear a fuel pump, but not sure if I should be able to? It's been a while ...

Not sure what I should check next? FWIW, the car sat for a year with fuel stabilizer. Please help with a list of things I can do for trouble-shooting!

Thanks!

George

aigel 05-20-2012 11:30 PM

http://forums.pelicanparts.com/uploa...1337585370.jpg
http://forums.pelicanparts.com/uploa...1337585384.jpg

herman maire 05-21-2012 03:58 AM

It sounds like its just a wiring issue. Is the gap on the pulse sensor correct , is that properly plugged in?

Do you have a spare dme and fuel pump relay to try ? I would just go over all the wiring.

did you check the plug for the distributor and coils ?

T77911S 05-21-2012 03:59 AM

if it has a crank posistion sensor, (CPS) i would start there first.

Groesbeck Hurricane 05-21-2012 04:45 AM

What about the alarm disconnect? Is this disabled? Could the alarm have been activated?


No spark and no fuel but the engine turns over? Something is preventing the fuel and spark. Could these be related or not? Sorry just trying to think out loud...


Have you gone over the DMEs? Are all the connections fully seated? It is worth a second go around all connections, I know I have left them undone before! Heck, on my F250 one of the connections I had just verified became self disconnected in the time it took me to put the valve cover back on.

Simple stuff first.

Bill Verburg 05-21-2012 05:13 AM

Sounds like an electrical issue to me

immobilizer?

aigel 05-21-2012 06:01 AM

Quote:

Originally Posted by herman maire (Post 6759197)
Is the gap on the pulse sensor correct , is that properly plugged in?

Checked the crank sensor connection, unplugged and put it back with no difference. I did not gap the pulse sensor because I installed the same flywheel. I do not think I disturbed the old pulse sensor, but it sure sounds like that's high on the list of issues. If the ECU does not see the engine rotating, it does not turn on fuel or spark? A new pulse sensor is >$150. Is there a way to test it without just throwing a new one at it?

Quote:

Originally Posted by herman maire (Post 6759197)
Do you have a spare dme and fuel pump relay to try ?

No spare yet. This is another one high on the list. I bench tested the relay and it closed both contacts. I have a new one on the way, arriving tomorrow.

Quote:

Originally Posted by herman maire (Post 6759197)
I would just go over all the wiring.

I disconnected an re-connected all the main connections in the connector box I feel I have good contact here.

Quote:

Originally Posted by herman maire (Post 6759197)
did you check the plug for the distributor and coils ?

The plug on the dist is on, the coils are connected and I do not think I have them backwards. The other end of these connections are the main connection in the connector box - as said above, those connections look reasonable.

Thanks!

George

aigel 05-21-2012 06:04 AM

Quote:

Originally Posted by Bill Verburg (Post 6759279)
Sounds like an electrical issue to me

immobilizer?

Bill - that's interesting. Wouldn't it completely shut it down, like in not even cranking?

I do have my alarm key fob and it goes through the usual motions where I can lock / alarm the car and unlock / disarm before it will "start" (in my case now crank over).

Thanks!

George

aigel 05-21-2012 06:09 AM

Fuel Pump???
 
Of course something random could have gone bad over the hibernation period, but most likely this is related to R&R or the long time sitting unused. We have addressed some of the connection stuff due to R&R but how about the long hibernation?

What if the fuel pump seized. Would it throw a fault for over-current and have the ECU hold back spark as well? A seized fuel pump seems something fairly likely after sitting? How could I check the fuel pump? Where is it located and how can I test it / jump power to it without destroying it?

Thanks!

George

Lorenfb 05-21-2012 07:33 AM

"What if the fuel pump seized. Would it throw a fault for over-current and have the ECU hold back spark as well?"

No, the DME ECM has no direct feedback from the fuel pump.

It's simple to diagnose a '97 993, i.e. just connect an OBDII scanner - all the data will be there.

"How could I check the fuel pump? Where is it located and how can I test it / jump power to it without destroying it?"

A waste of efforts, do the easiest tests 1st, i.e. test for spark.
Read here; http://www.systemsc.com/diagnostic.htm, it should be helpful.

Newsboy 05-22-2012 03:19 AM

You can use jumpers on the DME relay pins to see if the fuel pump runs. I had the same symptoms, and it was the flywheel speed sensor. To test this, I opened the DME relay(under the driver's seat) and used a multimeter set to AC voltage, across pins 47 & 48 of the large plug. iT's supposed to read 3 volts, I got zero.

herman maire 06-01-2012 05:29 AM

Did you ever figure out the problem ?

aigel 06-01-2012 09:57 AM

I ran out of time in my garage - moving households. So, off it went to TRE!

http://forums.pelicanparts.com/uploa...1338573270.jpg

TRE found it to be a connector problem. Disassembled and re-assembled all engine electrical connection in the main bulkhead area - bingo. I am not sure why this same trick didn't work when I did it, but that's why they are mechanics and I am not. ;)

Remaining work is repairing the rear bumper from heat damage (OP had taken off the muffler heat shields), respray and reinstallation. Connect the blower, a/c, smog and off I am with an almost new car! (Trans brand new, engine rebuilt by PO)!

edit: The gas was 1+ years in there and it runs fine on it. I gave it the max dose of Stabil. Nice to see how well that stuff works.

G


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