Intermittent Starting Problem
Discussion
I've got an intermittent starting problem which I'm struggling to diagnose. It seems random and it doesn't matter whether the engine is hot or cold.
I turn the key and the fuel pump primes, but the starter solenoid either doesn't click at all or clicks faintly. Sometimes the starter will make a momentary attempt to turn. If I wait a few seconds and try again, it will sometimes start. It may take as few as 3 or as many as 10 attempts before it will crank and start
.
It's a 98 car which I've owned for 12 years with no previous issues like this. The starter motor, alarm and all starter circuit wiring are original. The battery is less than 12 months old , the 100amp fuse is new and the charging circuit is healthy.
I've read all the threads I can find on the Hot Start issue, but as I've said this doesn't appear to be heat related. From what I've read, the problem would appear to be in the low current side of the circuit but the frustration is that I can't get it to replicate the problem now I've got it jacked up and I'm stood here with my multimeter in hand.
I know if I set off to go anywhere, Sods Law dictates that the bloody thing will undoubtedly play up again, and the worry then is that it won't start at all.
I'm tempted to just take off and inspect the starter motor and solenoid, and look for anything obvious to eliminate any faults with those but any other suggestions would be welcome.
I turn the key and the fuel pump primes, but the starter solenoid either doesn't click at all or clicks faintly. Sometimes the starter will make a momentary attempt to turn. If I wait a few seconds and try again, it will sometimes start. It may take as few as 3 or as many as 10 attempts before it will crank and start
.
It's a 98 car which I've owned for 12 years with no previous issues like this. The starter motor, alarm and all starter circuit wiring are original. The battery is less than 12 months old , the 100amp fuse is new and the charging circuit is healthy.
I've read all the threads I can find on the Hot Start issue, but as I've said this doesn't appear to be heat related. From what I've read, the problem would appear to be in the low current side of the circuit but the frustration is that I can't get it to replicate the problem now I've got it jacked up and I'm stood here with my multimeter in hand.
I know if I set off to go anywhere, Sods Law dictates that the bloody thing will undoubtedly play up again, and the worry then is that it won't start at all.
I'm tempted to just take off and inspect the starter motor and solenoid, and look for anything obvious to eliminate any faults with those but any other suggestions would be welcome.
Edited by sparkythecat on Saturday 24th May 13:22
Well, the starter motor and solenoid have been taken off, cleaned up and bench tested. They appeared to be working fine and the teeth don't show inordinate wear. The the crimp on the switched wire to the solenoid wasn't as tight as it may have been, but it is now.
In the absence of any better suggestion, I'll just have to keep running it until the problem shows again. It seems pointless speculatively replacing any components until I can identify which one is causing the problem.
Can anyone tell me the way to bypass the immobiliser circuit, to test if this cures the problem next time it happpens? PM me if necessary.
In the absence of any better suggestion, I'll just have to keep running it until the problem shows again. It seems pointless speculatively replacing any components until I can identify which one is causing the problem.
Can anyone tell me the way to bypass the immobiliser circuit, to test if this cures the problem next time it happpens? PM me if necessary.
QBee said:
+1 for solenoid. But I agree that the starter switch can give similar symptoms and has been found to be the cause on at least one case recently reported on here.
Is the starter switch behind the dash or in the steering wheel shroud?Edited by QBee on Saturday 24th May 13:53
Thanks for the detailed reply ChimpOnGas. I was hoping you might post on this thread.
Just a couple of questions.Does the dash have to come out to access the immobilizer circuit?
Can the battery cable be inspected properly in situ or does it need to removed and does it pull through easily or is it a pig to remove?
Just a couple of questions.Does the dash have to come out to access the immobilizer circuit?
Can the battery cable be inspected properly in situ or does it need to removed and does it pull through easily or is it a pig to remove?
Edited by sparkythecat on Monday 26th May 22:33
This thread is brilliant. 
Many thanks to those who have posted and those who have PM'd me.
I know that logicallly I should be trying to diagnose the problem when its occurring and car won't start and I could then more accurately pinpoint the cause.
But, ironically it's starting easily whether hot or cold just at present, but with a trip to France due in a few weeks I need to engineer out the most likely causes.
A new ignition switch is less than a tenner and given the sheer volume of them for sale on eBay, there must be a very high attrition rate so I think I'll replace that any way
I will also bypass the immobilizer relay as suggested by ChimOnGas, but if i do,should i put another relay in the starter circuit? as when I bench tested the starter, the solenoid was drawing around 8 amps when engaged.
Many thanks to those who have posted and those who have PM'd me.
I know that logicallly I should be trying to diagnose the problem when its occurring and car won't start and I could then more accurately pinpoint the cause.
But, ironically it's starting easily whether hot or cold just at present, but with a trip to France due in a few weeks I need to engineer out the most likely causes.
A new ignition switch is less than a tenner and given the sheer volume of them for sale on eBay, there must be a very high attrition rate so I think I'll replace that any way
I will also bypass the immobilizer relay as suggested by ChimOnGas, but if i do,should i put another relay in the starter circuit? as when I bench tested the starter, the solenoid was drawing around 8 amps when engaged.
Just an update to finish the thread.
Following the instructions mailed to me by ChimponGas, I disconnected the originaL feed to the starter motor solenoid and installed a new starter motor circuit, completely bypassing the immobiliser.
Six weeks and 2000miles later still no repeat of the starting problem.
Excellent !
Following the instructions mailed to me by ChimponGas, I disconnected the originaL feed to the starter motor solenoid and installed a new starter motor circuit, completely bypassing the immobiliser.
Six weeks and 2000miles later still no repeat of the starting problem.
Excellent !
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