lets discuss Crank Position Sensors for a moment
#16
Btw, cleaning the cable contacts are not enough. Those cables can look fine but when you peel back the insulation, the copper is all GREEN, heavily corroded inside. I did voltage drop test on that y starter/alternator cable and able to detect I almost lost 0.5v on that 3 feet cable. Decided to change it out and sure enough, the cable was heavily corroded at the crimp point.
#17
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I've got a used CPS that should be good.... I'll loan it to you if you want to troubleshoot with it?
http://forums.pelicanparts.com/porsc...000-996-a.html
http://forums.pelicanparts.com/porsc...000-996-a.html
#18
One quick test. When it cranks slow, jump start it with another car idling at the engine jump start terminal and the airfilter bolt.
If it starts fine, your problem is electrical between the battery and the starter (since you already eliminated the ground strap with a jumper cable before.
Very difficult to believe the engine is running fine then seize tge next second after it stopped. You hand crank test just verified that.
If it starts fine, your problem is electrical between the battery and the starter (since you already eliminated the ground strap with a jumper cable before.
Very difficult to believe the engine is running fine then seize tge next second after it stopped. You hand crank test just verified that.
thou I would connect the - cable to the engine. This would rule out the ground cable.
#21
#22
#24
#26
Rennlist Member
Thread Starter
He is not looking at ground points on the engine. He is looking for #18/34 that connect 19 and 17. Anyone knows? He has already replaced 21/22 and cleaned the contacts on 29.
Attachment 743944
Attachment 743944
#27
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here is a video of the issue:
Video Link: http://www.youtube.com/watch?v=TgMvS8-PcSc
Video Link: http://www.youtube.com/watch?v=TgMvS8-PcSc
Again, I've got an extra used good one... Can loan and if it proves to be your solution, I'm sure we can figure it out.
#28
Race Director
Well, I'm no expert but that behavior still looks to be voltage related. The first restart after the engine was warm I believe I spotted the voltage meter needle dropping to 0v.
It does not look to be a crankshaft position sensor related problem but if you want, if you can, borrow one and see. I may be wrong.
But I would not recommend you buy one unless you are comfortable with the risk that you may end up with a spare CPS to go with the perfectly good one that came out of the car.
I am glad to hear the voltage is 13.8V. That's a very good number. But I wonder what it is at the end of the trip?
One possible issue is the alternator starts out working just fine but it stops after some time. The engine manages to run ok for a while but back at the garage the battery can't restart the engine. After sitting a while the battery recovers -- though how long it can keep this up is a good question -- then the car restarts just fine. And the alternator is ok. For a while.
I encountered this once indirectly at a dealer service department. The tech had a car in his bay on the lift -- I can't recall the model of car now but I know it was a very new model year -- and out of curiosity I asked him what's the issue? He said the alternator. The symptom was the engine would start and run just fine idle just fine but after a few minutes the dash warning lights would come on the engine would begin to run poorly then the engine would die.
After turning off the key and letting the vehicle sit a few minutes the engine would fire right up and then do the same thing all over again. The tech traced the problem to an alternator that was not able to supply the electrical needs of the engine/vehicle.
Due to the battery's excellent condition it was able to supply sufficient power to start the engine and run the vehicle, for a while.
Oh, I might mention that my VW Golf TDi once lost its V-belt and among other things alternator power thus the vehicle was running solely on battery power. The car ran just fine for 15 or more miles as I drove into Albuquerque and stopped at a car parts store to pick up an alternator and belt and other things. The only sign something was amiss was a dash warning light was on. (That and the power steering and brakes were no longer power assisted.) My point is a car can run some miles without any apparent problems with no alternator power.
As an aside, and I do not necessarily think there is any connection, have you used a scan tool to view the engine coolant temperature, to put a number on it vs. just going by what the dash coolant temperature gage "reads"? If the temperature really is elevated this bears looking into.
It does not look to be a crankshaft position sensor related problem but if you want, if you can, borrow one and see. I may be wrong.
But I would not recommend you buy one unless you are comfortable with the risk that you may end up with a spare CPS to go with the perfectly good one that came out of the car.
I am glad to hear the voltage is 13.8V. That's a very good number. But I wonder what it is at the end of the trip?
One possible issue is the alternator starts out working just fine but it stops after some time. The engine manages to run ok for a while but back at the garage the battery can't restart the engine. After sitting a while the battery recovers -- though how long it can keep this up is a good question -- then the car restarts just fine. And the alternator is ok. For a while.
I encountered this once indirectly at a dealer service department. The tech had a car in his bay on the lift -- I can't recall the model of car now but I know it was a very new model year -- and out of curiosity I asked him what's the issue? He said the alternator. The symptom was the engine would start and run just fine idle just fine but after a few minutes the dash warning lights would come on the engine would begin to run poorly then the engine would die.
After turning off the key and letting the vehicle sit a few minutes the engine would fire right up and then do the same thing all over again. The tech traced the problem to an alternator that was not able to supply the electrical needs of the engine/vehicle.
Due to the battery's excellent condition it was able to supply sufficient power to start the engine and run the vehicle, for a while.
Oh, I might mention that my VW Golf TDi once lost its V-belt and among other things alternator power thus the vehicle was running solely on battery power. The car ran just fine for 15 or more miles as I drove into Albuquerque and stopped at a car parts store to pick up an alternator and belt and other things. The only sign something was amiss was a dash warning light was on. (That and the power steering and brakes were no longer power assisted.) My point is a car can run some miles without any apparent problems with no alternator power.
As an aside, and I do not necessarily think there is any connection, have you used a scan tool to view the engine coolant temperature, to put a number on it vs. just going by what the dash coolant temperature gage "reads"? If the temperature really is elevated this bears looking into.
#29
One possible issue is the alternator starts out working just fine but it stops after some time. The engine manages to run ok for a while but back at the garage the battery can't restart the engine. After sitting a while the battery recovers -- though how long it can keep this up is a good question -- then the car restarts just fine. And the alternator is ok. For a while.
In first hot start the volt gauge goes slowly to 10v (bottom).
When engine run's, the v-gauge show's only 13v.
And when you try to start it last time, v-gauge drops below 10v fast.
Try to jump the car from the battery, this way you can be sure that all the cables are ok.
If the car starts normally, I'd say that Macster's suggestion is spot on.
#30
Rennlist Member
Thread Starter
I took a v read at battery and at engine compartment jump point today when hot, while running, I had 13.7X
I cleaned the connection where the + batt lead connects at the fire wall. No change. I'm going to clean the other one that has to be somewhere under the car After it cools off a bit. I really think its a starter issue. And yes McMaster, the voltage may very well drop to zero if I stall the stater motor. An electric motor is pretty much a short if its stalled.
I cleaned the connection where the + batt lead connects at the fire wall. No change. I'm going to clean the other one that has to be somewhere under the car After it cools off a bit. I really think its a starter issue. And yes McMaster, the voltage may very well drop to zero if I stall the stater motor. An electric motor is pretty much a short if its stalled.