Car will NOT start. Possible cause appreciated
10-26-2009, 11:09 PM
#16
Drifting
OK, now you really have me mystified. What is the "puck?" Never heard of one of those in a M96 engine. Did he remove one or more of the chain tensioners and start or turnover the car without them installed? I am really curious as to how a flywheel swap lead to bent valves. Sorry you had this problem.
Have you checked for power to the fuel pump? and the fuse. You should be able to use a volt meter and check for power at the leads to the fuel pump in the trunk.
How did you check the pulse sender? Did you use a Durametric or a PST2 to check for fault codes?
Have you checked for power to the fuel pump? and the fuse. You should be able to use a volt meter and check for power at the leads to the fuel pump in the trunk.
How did you check the pulse sender? Did you use a Durametric or a PST2 to check for fault codes?
10-27-2009, 09:22 PM
#18
Rennlist Member
Thread Starter
Remembering that I'm the least mechanically person I know and only pay for this stuff, as it was explained to me by J3 who are now dealing with this (very good reputation in SE btw- the head mechanic was voted the best by ALMS this year) the old mechanic who removed the flywheel also removed the puck/bearing behind it and this allowed the IMS to shift and with it perhaps tooth or two on the cam chains allowing the pistons to hit the valves. I may have it wrong but he showed me a schematic and the cam "locks" he uses to prevent this from moving.He fabbed his own locks (about 6" long bits of alu) but apparently Porsche make and sell them. Anyway I nodded pretending to understand.
He reasons that the car probably did not fire when this originally occured because as light as the valve stems are, they only just bent and there was no other collateral damage done.
The car is with J3 and they are going to trace where the signals starts and ends but apparently, as I said earlier the Pulse Sensor as possible cause was functioning. I don't believe there is any codes being thrown which leads me to believe that it is the immobilizer because it can activate, but not throw any codes because everything else may be functional.
It could be any number of things- e.g the elec door windows are out- perhaps the circuits need to be closed. They will just have to go through it all systematically. Stay tuned.
He reasons that the car probably did not fire when this originally occured because as light as the valve stems are, they only just bent and there was no other collateral damage done.
The car is with J3 and they are going to trace where the signals starts and ends but apparently, as I said earlier the Pulse Sensor as possible cause was functioning. I don't believe there is any codes being thrown which leads me to believe that it is the immobilizer because it can activate, but not throw any codes because everything else may be functional.
It could be any number of things- e.g the elec door windows are out- perhaps the circuits need to be closed. They will just have to go through it all systematically. Stay tuned.
10-31-2009, 01:44 PM
#19
Rennlist Member
Thread Starter
Update- after tracing signals seems most everything is functional (sparking, injectors etc.) but fuel pumps not operational.
Do 996s have same DME relay issues as 964/993 i.e. they are prone to failure?
Anyway this will be investigated further on Monday.
Do 996s have same DME relay issues as 964/993 i.e. they are prone to failure?
Anyway this will be investigated further on Monday.
11-01-2009, 01:37 PM
#20
Race Director
Fuel pump not running immediately upon turning on the key may simply be due to the fuel system being an on demand type. In this type of fuel system the fuel pump runs only when the engine needs fuel and this determined by a fuel pressure switch.
The constant running fuel pump is going away as this tends to pump hot fuel back into gas tank and increase vapor production from the tank which puts more demands upon the car's vapor recovery system.
The fuel pump can be forced to run though I do not have the details of what's involved. It most likely involves the signal from the fuel pressure switch needs to be interrupted and the fuel pump needs to have power sent to it by connecting some bridge points together in the wiring relay panel.
A competent shop should be able to trouble shoot this no problem but one that messes with an IMS end plate during a clutch flywheel R&R I have my doubts...
Be sure battery is fully charged. While in the shop a battery can run down as cabin or trunk or engine compartment lights are left on and the car is started or engine cranked and not run enough for the alternator to recharge the battery fully. The battery will not take kindly to being run down and can develop a bad cell or two and while it may crank the engine the engine will not start. The battery may have been on its last legs to begin with.
With a bad battery other electrical gremlin like symptoms can appear as well.
Sincerely,
Macster.
11-01-2009, 01:42 PM
#21
Rennlist Member
Thread Starter
If the mechanic in replacing the flywheel even touched the IMS end plate all bets are off as to why car is not starting. I can't imagine why this was even bothered and to have it "bothered" in such a way that valve timing affected and valves bent... words fail me.
Fuel pump not running immediately upon turning on the key may simply be due to the fuel system being an on demand type. In this type of fuel system the fuel pump runs only when the engine needs fuel and this determined by a fuel pressure switch.
The constant running fuel pump is going away as this tends to pump hot fuel back into gas tank and increase vapor production from the tank which puts more demands upon the car's vapor recovery system.
The fuel pump can be forced to run though I do not have the details of what's involved. It most likely involves the signal from the fuel pressure switch needs to be interrupted and the fuel pump needs to have power sent to it by connecting some bridge points together in the wiring relay panel.
A competent shop should be able to trouble shoot this no problem but one that messes with an IMS end plate during a clutch flywheel R&R I have my doubts...
Be sure battery is fully charged. While in the shop a battery can run down as cabin or trunk or engine compartment lights are left on and the car is started or engine cranked and not run enough for the alternator to recharge the battery fully. The battery will not take kindly to being run down and can develop a bad cell or two and while it may crank the engine the engine will not start. The battery may have been on its last legs to begin with.
With a bad battery other electrical gremlin like symptoms can appear as well.
Sincerely,
Macster.
Fuel pump not running immediately upon turning on the key may simply be due to the fuel system being an on demand type. In this type of fuel system the fuel pump runs only when the engine needs fuel and this determined by a fuel pressure switch.
The constant running fuel pump is going away as this tends to pump hot fuel back into gas tank and increase vapor production from the tank which puts more demands upon the car's vapor recovery system.
The fuel pump can be forced to run though I do not have the details of what's involved. It most likely involves the signal from the fuel pressure switch needs to be interrupted and the fuel pump needs to have power sent to it by connecting some bridge points together in the wiring relay panel.
A competent shop should be able to trouble shoot this no problem but one that messes with an IMS end plate during a clutch flywheel R&R I have my doubts...
Be sure battery is fully charged. While in the shop a battery can run down as cabin or trunk or engine compartment lights are left on and the car is started or engine cranked and not run enough for the alternator to recharge the battery fully. The battery will not take kindly to being run down and can develop a bad cell or two and while it may crank the engine the engine will not start. The battery may have been on its last legs to begin with.
With a bad battery other electrical gremlin like symptoms can appear as well.
Sincerely,
Macster.
11-03-2009, 05:28 PM
#22
Rennlist Member
Thread Starter
It lives!
Don't have all the precise details but the car is running. Bad fuel pump relay (and ground- which exactly, I'm not sure yet). I heard it over the tel running The new exhaust barks like a Cup car- J3 like it and said it was built by a "craftsman" which is high praise.
Just in time for Barber in 10 days.
Don't have all the precise details but the car is running. Bad fuel pump relay (and ground- which exactly, I'm not sure yet). I heard it over the tel running The new exhaust barks like a Cup car- J3 like it and said it was built by a "craftsman" which is high praise.
Just in time for Barber in 10 days.
11-03-2009, 05:43 PM
#23
It lives!
Don't have all the precise details but the car is running. Bad fuel pump relay (and ground- which exactly, I'm not sure yet). I heard it over the tel running The new exhaust barks like a Cup car- J3 like it and said it was built by a "craftsman" which is high praise.
Just in time for Barber in 10 days.
Don't have all the precise details but the car is running. Bad fuel pump relay (and ground- which exactly, I'm not sure yet). I heard it over the tel running The new exhaust barks like a Cup car- J3 like it and said it was built by a "craftsman" which is high praise.
Just in time for Barber in 10 days.
)
