Hi guys.......help please!
just recently, the glow plug light on the dashboard came on only intermittently, cranking became sluggish, and starting was adversely affected. I renewed the pre-heat/glow-plug relay, and now I'm at a stage where the glow plug light on the dash always comes on when cold, but only stays on for about 2 seconds, not the 5 or 6 I'm used to, and the cranking/starting hasn't been improved. Recently I cleaned up the earth connection from the battery, and starting had been very good. Yesterday, I also cleaned up the connections to the starter motor too. This speeded up the cranking somewhat, but has not restored the good starting. I've done the following checks using the circuit diagram from the Haynes manual on the car:
Battery voltage is between 12.5 and 13.
Power to the ignition switch is good, as is continuity through the switch
I'm getting 12 volts at PIN 3 of the 5-way plug in connector to the preheat relay, only 9.5 volts to PIN 4 when cranking.. (Both those come from the ignition switch)
I'm getting battery voltage across the two eyelet connectors to the relay which are the power in from the battery and power out to the glow plugs.
I'm getting 10.5 - 11 volts at each of the glow plugs, and my test bulb lights when I connect it between the feed wire to the glow plugs and plug 2. (I'm assuming the others are good too. They were replaced earlier this year and have done less that 8k miles)
This voltage and current to the plugs stays on after the glow-plug light on the dash goes out BUT, STARTING AND CRANKING ARE STILL NOT GOOD, though she will start!
Also, the glow-plug relay clicks on when I turn the ignition key, but only clicks off when I turn the ignition key off again.
I'm suspecting that the relay, although new, is faulty.
Any ideas or suggestions would be gratefully received.
Thanks alot
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Not sure where best to start, but one thought that's just occurred to me is to check the earth strap from the gearbox....
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How long do the glow plugs stay on for? Connect meter to glow plug feed and watch it, count the seconds before it goes off.
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thanks to you both. The earth from the battery is good, and the test bulb connected in series with the first glow plug, stays on for well over 30 seconds. I didn't count any longer. I've since exchanged the pre-heat relay as Hella technical people thought it might be faulty when I explained the symptoms. This hasn't helped.
I'm starting to think it might be a dodgy starter motor explaining the sluggish starting. The fact that the glow-plug light only stays on a few seconds might be cos of the high ambient temperatures we're having at the mo?
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Hi again. This is finally solved! It turned out to be a partially corroded bolt securing the negative lead from the battery to the engine/gearbox.
I was thrown off the scent of this one cos although I'd recently cleaned/replaced the eyelets at this point which had improved things back to normal, I didn't replace the bolt itself, which I now know was dodgy!
regards
Tony
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RW wrote on 25th July: "but one thought that's just occurred to me is to check the earth strap from the gearbox...."
It's true then... I AM a soothsayer!!!
Glad you got it sorted cheaply.
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Hi Just because glow plugs have only done 8K is no reason to assume they are Ok. I fitted some to my Xantia in October and by christmas I had hard starting which in the end turned out to be the glow plugs, I had used Durite and went back to Bosch and have had no problems since, it may well be that you could try a couple to see if that improves staring, then fit the others if it does.
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Congratulations Richard! You know what it's like when you're thrown off the scent cos you think you've already checked that bit?! Thanks again for your help.
Tony
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