85 928S wont start after valve job....
05-07-2002, 11:25 AM
#1
Track Day
Thread Starter
85 928S wont start after valve job....
my 928S (32v) won't after doing a valve job due to broken t-belt. I haven't quadruple-checked my cam-timing (I was very thorough with the manuals when installing them), though the ticks all align, plug wires are correct, grounds, power leads, fuses, relays, computers have all been checked.
I think it may be the crank trigger, but unsure (haven't tested it yet). If you crank the motor with the sensor disconnected, it spins just fine. If you connect the crank trigger, the motor spins slowly, then almost stops, then spins slowly again, then almost stops, etc. (it's not the starter obviously).
Anyone have a similar situation??
Chris.
I think it may be the crank trigger, but unsure (haven't tested it yet). If you crank the motor with the sensor disconnected, it spins just fine. If you connect the crank trigger, the motor spins slowly, then almost stops, then spins slowly again, then almost stops, etc. (it's not the starter obviously).
Anyone have a similar situation??
Chris.
05-07-2002, 11:53 AM
#2
Rennlist Member
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Based upon the symptoms, my guess is that you have the plug wires installed incorrectly. Sounds like at least a couple of cylinders firing at the wrong time.
A caution - it is possible to damage the starter and perhaps even the timing belt and tensioner if the kick-back is severe enough
A caution - it is possible to damage the starter and perhaps even the timing belt and tensioner if the kick-back is severe enough
05-07-2002, 12:14 PM
#3
Track Day
Thread Starter
Thanks for the info Wally, I even tracked down a \nother local 928S4 owner to compare plug wires, his car still has the gold emblem on the radiator showing the firing order & wire sequence on the caps, pretty sure that's not it. I had it correct to begin with, then messsed with it (no real backfires), then returned it to the original placement (exactly as per the plate)
Chris.
Chris.
05-07-2002, 12:58 PM
#4
Instructor
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hi
check your distributor timing. its all too easy to get it 360 deg crank revolutions out.
check that pot 1 is on its compression stroke, coming up with both valves closed (sorry yours is 32V - 4 valves closed!), stop with pot 1 at top. then check your crank is at tdc, and then check that your distributor rotor is pointing at plug lead 1.
also check cam timing at this mark......
have fun, and good luck.....gotta to be something daft!
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johnb
check your distributor timing. its all too easy to get it 360 deg crank revolutions out.
check that pot 1 is on its compression stroke, coming up with both valves closed (sorry yours is 32V - 4 valves closed!), stop with pot 1 at top. then check your crank is at tdc, and then check that your distributor rotor is pointing at plug lead 1.
also check cam timing at this mark......
have fun, and good luck.....gotta to be something daft!
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
johnb
05-07-2002, 09:42 PM
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Three Wheelin'
Join Date: May 2001
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For some MY 85 cars, before VIN. 920 FS 860142, the firing orders on the label and distributor caps are incorrect. The car will not start. It should be 1 3 7 2 6 5 4 8
Steve C
The Great White
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Steve C
The Great White
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
