Diesel no longer liking cold starts...

[madlec]

Hi all,

I have a '95 Diesel which has been running fine all winter. Recently I have been noticing that the glow plug relay going nuts as the engine reaches running temperature (on, off, on, off etc) when idling. So I added it to my to do list, and moved on...
Now when trying to start it up, around and below 5oC the rad fans spin up before I even turn the engine over, and once started it coughs and splutters for about 20 seconds and dies. As far as I can hear all the "clicks" are happening when I turn the ignition on, but with my head in the cab and the rad fans on, I can't hear the glow plug relay.
From what I have read, it is looking like the coolant temp sensor under the cold start solenoids is the culprit, but before I start dismantling anything, I was wondering if anyone has had similar and can confirm. Also, as it's the coolant temp sensor, I am guessing that I will need to bleed the system again after changing it

Thanks

[wonkanoby]

fans come on if a/c is on

how old are the glowplugs

are they getting power to the rail joins them

[madlec]

The a/c is off, and I don't know how old the plugs are. They haven't been changed in the year we've had her

I will keep my multi meter handy so I can test when it next has problems. I believe there is power getting to the plugs, because when I turn the ignition on, and the fans don't spin up, the engine starts with no problem, even when it's cold out side.

I started it up 1st time on the way home from work this evening (16oC ish), so it's definitely when it's cold. Tomorrow is forecast to be cold in the morning, so I can try to test the power to the plugs then.

[Northern Bongolow]

when starting a bongo when the starter battery is down it puts the fans on. suggest you test the cranking ampage of the starter battery.

check this out it may help you check the condition of the battery, even if its reading 12 volts it could be knackered.

http://www.igmaynard.co.uk/bongo/forum/ ... st#p650584

[madlec]

Thanks for the battery tip.
I tried the voltage drop test, and when cranking, the battery dropped to just under 10v, so I assume its o.k.

The only other things I have noticed are that when I am going to have the cold start problem, the glow plug light on the dash stays on longer than normal, sometimes a good few seconds longer, and as soon as it goes off, the engine fans kick in. Also my coolant level was a little low. Although, unless I am missing something, this would only cause the engine fans to kick in sooner once the engine has warmed up

The other day when I started it up, there were no issues initially, but after about 30 seconds, the engine fans kicked in again and the engine started misfiring. Assuming it was because it was still under running temperature, I gently increased the revs to 2k and backed off again, then it started running smoothly albeit just under normal idle speed.

Today, I had no problems at all, it started fine, and ran fine (no running engine fans) which seemed to muddy the waters even more.
I have ordered a new temperature sensor, and will swap it out over the weekend if over the next couple of days the cold start issue comes back.

[rita]

madlec, there is (should be) a connector a few inches before the ETC sensor, it would be worthwhile making sure that this connection is sound and clean when fitting the unit.

Good Luck.

[madlec]

I found the connector, should have checked that before replacing the sensor. After reseating it, the cold starts are fine, and the engine fans don't spin up prematurely. So the old sensor lives to see another day.
I am still hear the glow plug relay going into spasm when the engine is warming up, but once it is at running temperature, it is fine again. Something for investigation at a later date

[rita]

As they say "easy cheap fix"

Re the glow plugs, the glow plugs stay active until the ECT sensor detects approx. 50 degrees and or the RPM goes above 1000/1500 RPM.

In actual fact depending on the type of driving that you are doing ...the GPs can basically be on all day.

Good Luck.