[urq] intermittent no crank

[Steve Buchholz]

I don't see any mention of the ground braid. You will find it going from the block to the unibody near the spark plug side engine mount. Check the quality of the braid and that the fasteners are snug.
I had a tough to find no crank issue on my 5kCSQA ... would usually happen when my wife was driving the car ... turned out to be a loose ground at the battery where the ground cable attaches to the unibody. 
Good luck! Steve Buchholz

-------- Original message --------
From: Keith <spotatashleys at hotmail.com> 
Date: 2/6/2016  5:18 AM  (GMT-08:00) 
To: urq at audifans.com 
Subject: [urq] intermittent no crank 

Anyone who has been on the list for a while may well have read one of my earlier posts with this title. I’m getting closer to solving it but I’m not there yet.
I think I have had a number of issues running parallel because at one time it was intermittent no start as opposed to intermittent no crank  because sometimes it would crank and not start and other it would not crank. Now I just have the intermittent no crank having resolved a number of issues which I’ll list but now if it cranks it starts and starts instantly. Trouble is, sometimes there is a no crank issue.
So when it was intermittent no start I replaced plugs, cap, rotor arm, plug leads, coil lead, and coil, new fuel filter, all fuel pressures tested and confirmed in spec. Things improved. Then to counter the no crank issue I changed the ignition switch, the main battery to starter power cable, the battery, the starter the wires for starter solenoid and feed from there to cold start injector (from the connector behind the RHS headlight to the starter), yet still I have occasional no crank. This tends to happen when the battery is a little lower than full charge. I have tested for a parasitic drain on the battery. Off-Key drain is no more than 10 mA. The voltage of that battery today was 12.4V. If I disconnect the lead to the starter solenoid and put a meter on that and turn the key to start position it shows 11.9V which should be more than enough to activate the solenoid. This lead runs from the ignition switch to the jumper in relay position 8 in the fusebox (where an inhibitor relay would sit in and automatic transmission car) and from there round the engine bay to the grey connector under the RHS headlight and then on to the starter solenoid. As I say when this is disconnected and the voltage measured it shows 11.9V in start position. However, if I re-connect this to the starter solenoid and this time measure the voltage at the jumper in the fusebox (key is start position) it only reads 9.4V. Does anyone have any idea why this should be? I am confused.
I feel certain that I could overcome this by simply using a waterproof relay down at the starter solenoid, using the normal feed to the solenoid to trigger and take the main power for it from the alternator positive post but I’d really like to overcome it without have to resort to this.
Any words of wisdom gratefully received.

Many thanks

Keith

‘87 WR in a dismally wet Worcestershire.
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