JX cold start issue

[Oldiebut goodie]

As stated earlier I added the glass bodied filter so I could observe the fuel is getting through (& also if there were any air bubbles)

No previous mention of this.

When did you last drain the water from the filter?

[windy]

At lunchtime the primer bulb arrived, together with an extra glass bodied fuel filter, so I can see if the fuel is getting through.

I put a new Mann fuel filter on today, at the same time I was doing the other work. I drained the old filer into a clean jar, and there was no water in there. I also put a bottle of Wynns fuel dry in the last tankful of diesel.

[windy]

Over the past 5yrs I've had the van it has often thrown up staring problems, usually when quickly shut down from hot, but recently this different cold issue, and now a warm start problem! Everything in the fuel chain has been looked into, replacement pump & pipes (a couple of years ago), recon injectors (twice), same with the glow circuit, new glow plugs, sender & relay. I've checked the glow plugs have power as the engine is cranking & pre/post cranking. Fuel cut-off solenoid is getting power & clicks on/off.

BTW, I've built & repaired a lot of engines over the last 30-odd years, mostly petrol V6, V8, together with 4 & 2 stroke motorcycles, but I'm not too clued up on diesels, and this has got me stumped!

[Oldiebut goodie]

Have you tried using the cold start lever when hot - if using it makes a difference that could point to timing being out. Have you tried forcing the glow plugs to come on whatever the engine temp?

Just thinking - is the auxiliary water pump running after shut down? If not could be heat soak.

[windy]

Yes, the cold start lever used to help when hot, but I'm not sure now as I only retimed the pump mid week (set to 1mm) & have got into the habit of pulling the lever out every time I start. Will try without now.

In the past I did try leaving the glow sensor wire off to force the plugs on even when the engines hot & it made no difference.

Re the aux pump the engine never got hot enough for it to kick in & its removed at present.

To recap I think the cold starting issue is due to what was discussed earlier, and the primer bulb one/way valve has addressed that but a different version of the old hot start problem has come back to haunt me now!

The old hot start problem was if the engine "caught" within the first few seconds all was fine, but, if not, I knew that unless I didn't re-try for at least 20mins there was no chance it would start again. It would turn over but not fire, or chug but not continue to run without the starter assisting it.
If it was a petrol engine I would say with certainty it was showing symptoms of flooding, but how can that be possible with a diesel? Also when it does start & the unburnt diesel smoke has cleared it runs fine, has good performance & good fuel economy, only fault being it uses a fair bit of oil.

[muttleypup]

If the primer has solved the cold start problem then remove the additional filter and see what happens with hot starts and go from there. At least rule out the filter being an issue

[Oldiebut goodie]

Using oil may be some of the problem - have you done a compression test? Anything obviously wrong with valve operation (although your problem appears to be across all cylinders rather than just one)?
Looks like may be a combination of problems, heat soak, fuel supply/air, compression. A little bit of each acting together is hard to diagnose. I had an air ingress problem on my boat engine that I could never solve - it drained back slowly on every stop and it wasn't until I changed the fuel tank that I discovered the reason which was a pinprick hole in the standpipe that was used for fuel take off.
Your problem appears to me to be timing or compression. Diesel is obviously now getting to the injectors as indicated by the smoke when it finally starts so you don't have many more avenues to consider. Was the timing set again from scratch with the correct mark on the flywheel ( people have been known to have mistaken the lugs on the clutch for the timing mark) and all points locked off correctly?
These old basic diesels are so simple that it shouldn't be difficult to find out the problem area, rechecking everything carefully. At least we don't have all the electrical problems that comes with petrol engines and ignition.

[windy]

I was hoping it wouldn't be compression, but you may have something there. Bore/ring wear would explain the high oil consumption. I'll definitely have to obtain the necessary adaptor & check it out.
Pump timing was set to 1mm with a dial gauge from scratch but to me the engine feels too far retarded. I think it ran better at low revs with more advance before it was adjusted.

Mutleypup I will remove the glass filter, now I can see there are no air bubbles in the supply & it might be contributing to a heat soak issue.

[windy]

Just tried to start it without the cold start lever pulled out & it didn't like it.
Pulled lever out & it started normally, then pushed the lever back in after 30 secs & engine stopped, so does sound like timing is too far retarded.
Giving up for tonight & will start afresh in the morning

[Oldiebut goodie]

When was and who changed the timing belt ? Was the cam locked correctly and pump pinned when the timing was checked? It is very easy to get the belt one tooth out when changing it. Also if the belt tensioner hasn't been changed it may be failing and could lead to it jumping a tooth.

[windy]

Belt & tensioner was changed by myself a couple of years ago with everything locked & pinned. Pretty sure its all ok.

Yesterday I realised that until the weekend the van hadn't been started warm since the pump timing had been adjusted earlier in the week, then recalled that the temp gauge was reading higher than normal since then too. I'd marked the pump position before adjusting, so moved it back to its original position & now its running cooler again & starting from warm ok now too, so it does look like a heat soak issue caused by the higher than usual engine temp, in turn caused by the overly retarded timing.

After what seemed like a success we went on a 60 mile round trip, interspersed by a long walk, with no more issues starting from hot or cold either.

I tried starting the van from cold before I went to bed last night too, and it started up perfectly.

This morning went to start the van & it took 5 minutes before it would catch, and any more cranking would have very likely flattened the battery

[Timburrows]

Worth looking at the crank sprocket,may have some movement causing variable timing issues,sooner rather than later as it will be very costly if it fails

[windy]

Tim, the crank sprocket & bolt were both changed when the cambelt was done, as the old one had tooth damage. It's still tight, thankfully.

Yesterday the van started fine, so fingers crossed all is well again.

[windy]

Missed an appointment this morning due to the van taking 3hrs & 2 batteries to start
It just didn't want to fire, probably sulking as I didn't use it yesterday.
Compression tester adaptor is on order so will be looking into that next, and got an AAZ lined up as a replacement if the JX shows up as worn.

[Oldiebut goodie]

Going by that it does seem like the fuel is draining back with the longer standing time. Did you fit a separate one way valve or was that part of the priming bulb?