GT Unable To Idle And Very Rough Running
#17
Rennlist Member
So the fuel was drained from the tank and then the car sat idle for 6 mths with the old stale fuel in the pump, filter, lines, injectors etc.
I'd start with fresh high octane fuel with an additive to flush the system clean then check the spark plugs to ensure they're all getting fuel.............if not we can diagnose from there.
I'd start with fresh high octane fuel with an additive to flush the system clean then check the spark plugs to ensure they're all getting fuel.............if not we can diagnose from there.
#19
There was no fuel left in the car, as i had to work on one of the fuel lines
All 8 plugs are wet and sooty so its getting fuel
But for spark i'll check for that soon
All 8 plugs are wet and sooty so its getting fuel
But for spark i'll check for that soon
#21
Update
Today i thought i would try some ideas with a fully charged battery
Maf plug removed and temp 2 bridged= no start or trying to
Check EZK realy XXII clean terminals put back in and with ignition on and a fuse across green light comes on
Re try starting just turns over still no firing
Remove 1 plug lead LHS fit a plug in it and test for spark while cranking= has a spark
Try same as above but on RHS = has a spark
I checked that each lead i removed came from that sides dizzy
Check live going to coil LHS (US pass side) 11.5v with ign on but when cranking drops to 9.5v
Check battery 11.8v
Maf plug removed and temp 2 bridged= no start or trying to
Check EZK realy XXII clean terminals put back in and with ignition on and a fuse across green light comes on
Re try starting just turns over still no firing
Remove 1 plug lead LHS fit a plug in it and test for spark while cranking= has a spark
Try same as above but on RHS = has a spark
I checked that each lead i removed came from that sides dizzy
Check live going to coil LHS (US pass side) 11.5v with ign on but when cranking drops to 9.5v
Check battery 11.8v
#22
Burning Brakes
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11.8v is far to low for the battery. Try using another battery. I've had it in the past when a battery has enough juice to turn the engine over, but not enough to make it fire up.
#23
Rennlist Member
Battery sounds a bit low...
So you have spark, volts to coil are OK, now bridge fuel pump relay, or use known good substitute - let us know.
You could bridge FP relay, and do the flow test at the returtn to th top of the tank, 1350cc or more in 30sec.
So you have spark, volts to coil are OK, now bridge fuel pump relay, or use known good substitute - let us know.
You could bridge FP relay, and do the flow test at the returtn to th top of the tank, 1350cc or more in 30sec.
#24
Supercharged
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If you have spark, and plugs are wet, then my guess is you've flooded the engine. Try starting it with the accelerator mashed all the way. The 928 does not like to start when flooded (my experience). It may take 30 sec or more of cranking for it to get started. Watch out for the black plume of smoke.
#25
Rennlist Member
Just sitting there a fully charged batt should give more volts. How old is it? Probably should get it load tested. If the MAF is clean,
Then I would try to swap a good LH/EZK in it or check the volts at the pins and the grounds at the pin connectors in foot well. But the puter shouldn'd die from just sitting.
Then I would try to swap a good LH/EZK in it or check the volts at the pins and the grounds at the pin connectors in foot well. But the puter shouldn'd die from just sitting.
#27
I think Andrew is spot on, you got fuel and spark, so it's most likely just flooded. It's probably quite badly flooded from all the cranking, so I doubt it will fire without cleaning it up first.
I've had this problem so many times during winter that it's a miracle I haven't kicked in a side panel in pure frustration. It's worth trying the following steps before you start to pull out the electronics:
- Recharge battery overnight and clean up the ground spots around the coils and also the check/clean the coil connections and plug harness connections. Moisture is your enemy here.
- Take out and clean all the plugs, wipe them dry and check clearance.
- While the plugs are out, flush the cylinders by cranking it a few turns with FP fuse disconnected. Without plugs (compression) it will crank insanely fast so a second or so is enough.
- A q-tip taped to a thin long stick/wire can work as your "dip stick" to inspect the cylinders for fuel. Letting it sit an hour or so while the plugs are out also help to dry it up.
- Put it all together and start it with the throttle floored. It might still be damp and hesitant so crank it continuously, at least 10-15 seconds at the time until it fires.
If it still wont give any signs of life after this procedure, then it's time to investigate electronics.
When I start my shark I always give it a try first without touching the pedal, usually it starts very quickly, but if it wont catch at once I've learned to always retry with the pedal floored to avoid flooding.
I've had this problem so many times during winter that it's a miracle I haven't kicked in a side panel in pure frustration. It's worth trying the following steps before you start to pull out the electronics:
- Recharge battery overnight and clean up the ground spots around the coils and also the check/clean the coil connections and plug harness connections. Moisture is your enemy here.
- Take out and clean all the plugs, wipe them dry and check clearance.
- While the plugs are out, flush the cylinders by cranking it a few turns with FP fuse disconnected. Without plugs (compression) it will crank insanely fast so a second or so is enough.
- A q-tip taped to a thin long stick/wire can work as your "dip stick" to inspect the cylinders for fuel. Letting it sit an hour or so while the plugs are out also help to dry it up.
- Put it all together and start it with the throttle floored. It might still be damp and hesitant so crank it continuously, at least 10-15 seconds at the time until it fires.
If it still wont give any signs of life after this procedure, then it's time to investigate electronics.
When I start my shark I always give it a try first without touching the pedal, usually it starts very quickly, but if it wont catch at once I've learned to always retry with the pedal floored to avoid flooding.
#28
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My lh failure (87 s4) caused the cold start injector to click really loud, while running like total crap. Had it rebuilt, now runs perfect.
-Sam Johnson
78 euro 5spd
87 S4 5spd
-Sam Johnson
78 euro 5spd
87 S4 5spd
#29
Nordschleife Master
Failed MAF or MAF connector would give these symptoms (rough running, low power, hugely rich, wet/sooty plugs).
Try borrowing a MAF from another local 928er to test.
Try borrowing a MAF from another local 928er to test.
#30
Rennlist Member