Bart69
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| posted on 27/3/10 at 03:50 PM |
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20 XE Hot Starting Prob
This ha been an on going prob for 2 years now.
The car was used as a guinea pig at a snap on intro course to the modus scope and nothing showed any problems including injector current draw, ht
spark, fuel pump, AFM.
Sods law the car behaved great and only showed the symtoms for a few seconds before firing up. During that few seconds the instructor suggested the
crank sensor as the signal seemed weak when the car was cranking but that has been changed with no improvement.
The cars starts 99 times out of a 100 when cold.
When it's warm or maybe just cut out after a couple of minutes running it winds over fast enough but doesn't even try to fire for maybe 20
-30 seconds then starts to catch getting faster and finally firing up.
The engine does smoke a little and compressions are down slightly on spec at around 145 and 150 psi.
The car has been rich at last 2 mot's around 4.0. My spare afm made no difference and being precat in my 89 astra gte doesn't have a lamda
sensor.
Temp sender works fine checked more than once. She is a bit rattley from top end but does cam down.
She will always start with a bump start sometimes with a bit of kangaroo petrol but does go.
She runs great when started with plenty of oomph but is becoming a real pain which is stopping me using her as I can't trust her any more.
My only thoughts are dribbling injectors which would could cause flooding for a few hours untill it evaporates but how would that tie in with it not
starting after a stall.
Please help
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plentywahalla
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| posted on 27/3/10 at 05:34 PM |
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The symptoms you describe are identical to my Merc 300 SL 24valve
The problem on mine is the distributor is mounted on the end of one of the cams and so the dizzy body is part of the head. The alloy head is porous
enough to allow moisture into the dizzy. Just enough to create a critical humidity that causes what you describe. If you stall the engine when hot it
will not restart without extensive cranking with 1 then 2, 3 ,4, 5 etc cylinders coming in.
I've learn't now that I just have to whip the dizzy cap off and dry it out and it starts instantly. All the components have been replaced
but it persists. My local Merc guy says its endemic with these engines.
I don't know the 20 XE so it may be nothing to do with it.
Thought I would share it with you anyway.
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Bart69
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| posted on 27/3/10 at 08:49 PM |
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Thanks for that I'll have a look on the Xe there is a hall effect cam sensor in the dizzy so worth a look.
Anyone else any other suggestions ?
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dlatch
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| posted on 27/3/10 at 09:09 PM |
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i had a random non start issue with my old gte valver it turned out to be the ignition amp box, worth trying a replacement if you have one as these
components are getting very old now
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omega 24 v6
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| posted on 27/3/10 at 11:30 PM |
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Is this in a kitcar or the original tintop??
If it looks wrong it probably is wrong.
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Bart69
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| posted on 28/3/10 at 12:49 PM |
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quote:
Originally posted by omega 24 v6
Is this in a kitcar or the original tintop??
The car was bought for the engine for my locost but ended up getting restored first so it's still in the tintop.
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omega 24 v6
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| posted on 28/3/10 at 03:42 PM |
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OK well then there was a big issue with the fuel pump relay coils failing just like you are describing basically when the car is hot and you turn it
off the electrics under the bonnet get hot with the heat soak and the wire ends of the coil seperate thus stopping the pump from running so there is
no fuel. It is a well known problem among the older SOHC cars and i'd imagine the setup on the XE is not that different
If it looks wrong it probably is wrong.
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Bart69
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| posted on 28/3/10 at 05:35 PM |
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quote:
Originally posted by omega 24 v6
OK well then there was a big issue with the fuel pump relay coils failing just like you are describing basically when the car is hot and you turn it
off the electrics under the bonnet get hot with the heat soak and the wire ends of the coil seperate thus stopping the pump from running so there is
no fuel. It is a well known problem among the older SOHC cars and i'd imagine the setup on the XE is not that different
It's a new GM fuel pump/injection relay as the original got stolen when it was in the paint shop  although the wiring hasn't been
checked other than visually.
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omega 24 v6
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| posted on 28/3/10 at 05:52 PM |
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Well it should be ok if its new I suppose.
You could bridge out the pump terminals to make sure if you wanted to.
After that it's back to basics
Is there fuel/
is there spark ( and at the right time)
Is there compression.
If it looks wrong it probably is wrong.
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