XUD not starting when hot - Compression Test

[Harky]

Evening all,

Firstly apologies if this has been covered, I couldn't find it though.

Bit of a strange, and very annoying problem. My XUD basically won't start when warm, unless you bump start her, then she starts straight away. Starts ok when cold. So I changed the glow plugs, still the same. Glow plug light comes on, but tbh I haven't had a chance to check whether theres actually power going to them.

Not sure where to go now. Either the control relay, or possibly a temperature sensor? Looking advice on what to try next just? It's a Bosch pump, was running veg for years, has been on diesel the last 2 months, and that was when it started to get hard to start. Cold start cable is disconnected as well.

On a side note, did anyone know there are different sizes of glow plugs? Bought a set, went to put them in and they were too big, yet they were the same size as in my last engine. Then when I get to the awkward one behind the pump, its a big one!

Any suggestions very much appreciated!

[bashbarnard]

Someone may have put incorrect plugs in at some point. Not to sure on the hot start issue. Someone will be along shortly to say something clever no doubt

[Harky]

Thread title fixed!

The difference in the glow plugs was the stem thickness. The larger ones were physically too fat to fit through the head into the pre cup

[londondan86]

Is the timing ok mate?

[Harky]

Yea, timings grand, car goes the best, starts ok when cold, its just when hot I have problems. I'd be 90% sure its electrical

[zx_volcane]

obvs you need to check to see if you're getting power to your glowplugs first

if you are getting power to glowies, next thing I'd check is compression and also your valve clearances

[ally406]

You can bypass the relay using a jump lead and run the plugs for a few seconds manually, however if it starts fine from cold I think you can rule that out. Valve clearances would be my next port of call if you have ruled out a timing issue.

[Harky]

It starts with a bump start though? Valves are the last thing I want to be starting to look at. I'll try bypassing the glowplugs again tomorrow and report back then

[zx_volcane]

Valve clearances aren't hard to check - rocker cover off, and some feeler gauges between the buckets and the cam.

I'll admit they're a pita to change though!

[Harky]

Valve clearances would be in the Haynes manual wouldn't they? Or I don't suppose you know them off the top of your head :-p

[zx_volcane]

0.15mm intake, 0.3mm exhaust

[Harky]

0.15mm intake, 0.3mm exhaust

Cheers.

So checked power to the glow plugs. Power when cold starting, power when hot starting.

Only got started checking clearances. Of what I did check, exhaust seemed OK. Intake seemed a bit much, was +0.2mm. So I need to get them all checked tomorrow, see what I need. Where do I go about getting shims? I'm sure I would've had plenty from two scrap engines, if I hadn't scrapped all!

Whats the logic behind the valves causing this, can't really get my head around it?

[seanyleary]

A buddy of mine had this with an avensis, got the starter reconditioned and it's been perfect since.

[Dave]

I wouldnt go changing valve shims yet, I would do a compression test to see if you're down on compression when warm. I still think the extension of the valve isnt enough to cause horrendous starting issues if it starts from cold ok.

[Harky]

I wouldnt go changing valve shims yet, I would do a compression test to see if you're down on compression when warm. I still think the extension of the valve isnt enough to cause horrendous starting issues if it starts from cold ok.

I'll get a tester and try that then.

Checked valve clearance today. Inlet ranged from 0.15-0.2, Exhaust from 0.29-0.35. I'll report back mid week with compression test results, see if that shows anything up

[Daniel306]

Looks like it needs rings, dose it sound low on compression?

[Harky]

Looks like it needs rings, dose it sound low on compression?

I'd be lying if I said I knew if it sounded low or not! I've ordered a compression tester here, just hoping that I don't end up regreting running de-filtered for 2 years....

[HDIkyle]

I had this was starter motor

[Daniel306]

Dose sound like it turns over faster/easier on the key when hot?

I bet the rings are f*cked

[HDIkyle]

cold would fire straight up but once warm would just turn over until battery went dead. new starter and problem solved

[Daniel306]

We will see what it is when its had the compression is tested. but for me the description and "de-filtered for 2 years" has me convinced

[HDIkyle]

Mines always run defiltered and I drive down some terrible farm tracks but I guess its hit and miss

[Harky]

When I think about it now, that engines only been in a year, been defitlered all that time, previous engine was defiltered for a year before con rod went!

It'll be mid week before I get to update this, just summing up in my head whether its easier to get a new engine..again!

[Harky]

So after a nightmare with delivery, I finally got my compression tester, and due to a few days work over in England, I'm only getting round to looking at it tonight.

...And its a nightmare. Tried to do it through the glow plugs but the connections don't fit in behind the fuel pump, ended up only getting the one done.

Came up at 25 bar / 380 psi.

My question is, anyone know what it should be?

[Daniel306]

I think it should be Minimum 290psi cold with no more than 70psi difference

[Harky]

This was done hot, she starts ok cold, just an issue when hot.

Would being hot affect the starter in any way, she starts with a bump when hot, just not on the starter?

[Piggy]

For the sake of a second hand starter for a tenner?! Not worth a try?

[Harky]

For the sake of a second hand starter for a tenner?! Not worth a try?

Thinking of getting mine refurbed tbh. Mine doesn't seem too bad tbh, and I can't get my head around why being hot would cause the issue?

[Piggy]

Me neither BUT as said, for sake of a tenner, it would eliminate it

Does it idle or run differently prior to bad starting when hot? Make any difference if you prime the fuel up?

[zx_volcane]

So after a nightmare with delivery, I finally got my compression tester, and due to a few days work over in England, I'm only getting round to looking at it tonight.

...And its a nightmare. Tried to do it through the glow plugs but the connections don't fit in behind the fuel pump, ended up only getting the one done.

Came up at 25 bar / 380 psi.

My question is, anyone know what it should be?

380 psi sounds fine to me - really you're looking for consistency between cylinders

did the kit not come with adaptors or 90 degree bends so you can get around your fuel pump?