Cardies after 45-60 mins driving.Ignition failure. WHy?
02-02-2009, 05:22 PM
#1
Instructor
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Cardies after 45-60 mins driving.Ignition failure. WHy?
Hello,
I have a 2.7 1989 944, and it starts fine in the morning, drives alright, and then after about 45-60 minutes, it stutters for like 10-15 seconds, then dies.
I can start it right away after with some cranking, but then it will die again withing 5 minutes, then crank, start, after 5 minutes dies, crank, start.
If the car "rests" for a longer time, then it will run for the mentioned 45-60 minutes before this happens.
I have traced it down to it loses ignition when it happens. (By the use of a ign.lamp.) BUT WHY??
I have changed spark plugs, DME, rotor. Wiggled reference connectors.
What can cause this? I am tempted to get a new ECU.
I can also say that it will die easier after the 45 minutes if car is idling it seems. You notice the idling gets crappy for 10 secs, then dies completely.
During driving, same thing, runs like crap for +/- 10 secs, then dies.
I cannot understand why I can start it again right away, so any help would be welcome.
Thanks.
Regards Boerge
I have a 2.7 1989 944, and it starts fine in the morning, drives alright, and then after about 45-60 minutes, it stutters for like 10-15 seconds, then dies.
I can start it right away after with some cranking, but then it will die again withing 5 minutes, then crank, start, after 5 minutes dies, crank, start.
If the car "rests" for a longer time, then it will run for the mentioned 45-60 minutes before this happens.
I have traced it down to it loses ignition when it happens. (By the use of a ign.lamp.) BUT WHY??
I have changed spark plugs, DME, rotor. Wiggled reference connectors.
What can cause this? I am tempted to get a new ECU.
I can also say that it will die easier after the 45 minutes if car is idling it seems. You notice the idling gets crappy for 10 secs, then dies completely.
During driving, same thing, runs like crap for +/- 10 secs, then dies.
I cannot understand why I can start it again right away, so any help would be welcome.
Thanks.
Regards Boerge
02-28-2009, 05:41 AM
#2
Burning Brakes
If it starts and runs perfectly even for just 45 mins I think I would be looking at fuel pressure and delivery.
Have you tested the FPR by testing the fuel pressure ? pressure might be too high . If it is the 12v+ pulse to the injectors is shut off I believe.
The other possibility is a blocked vent to the petrol tank ? try running it with the gas filler cap off see if it makes any difference.
Might be worth having a quick recce on Clarkes Garage site at their tech articles in Garage Workshop section
Have you tested the FPR by testing the fuel pressure ? pressure might be too high . If it is the 12v+ pulse to the injectors is shut off I believe.
The other possibility is a blocked vent to the petrol tank ? try running it with the gas filler cap off see if it makes any difference.
Might be worth having a quick recce on Clarkes Garage site at their tech articles in Garage Workshop section
03-14-2009, 11:28 AM
#3
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I know nothing about porsches yet, came here because i`ve always wanted a 944 and i want to get clued up, but i have done a lot of autosparking in my previous job doing lpg conversions, if your defineatly losing coil output sounds like it might be a temperature related failure of the pickup sensor(crank or cam?) or the coil amp maybe is it separate or is it in the ecu? coils can also fail when hot. I would recommend you spend £3 on a can of freezer spray from an electronics shop, drive til you get the problem, then freeze those components one at a time then try to run it seeing which one stops the problem. Hope this is of some help or you can just say stfunoob
