Another van won,t start thread.

[Woody49]

Hi all once again, I have had a year of trouble free motoring but now am suffering from the van won't start issue. To be more precise its a van won't keep going issue today. Story so far. Van was going good with only a failure to idle at junctions issue, recon engine 1.9 dg petrol engine, Bromyard carb job and all ignition components in good order.

Battery went dead and when replaced with new after a few weeks of not being used the van refused to start. AA man thought it was a carb issue, so off to bromyards with the carb, nothing found wrong apart from set up, so try again and still no joy. Second AA man got a momentary turn over very rough, high revs etc. but he thought it was a dizzy issue . Van towed back home and I have tried everything I know including spare dizzy and coil and new plugs. Getting spark at all plugs, down in compression on cylinder 3 ( 10 bar v 12bar for the others) no apparent vac leaks, petrol delivery fine. Anyway got the van going (using easy start naughty me).

What is confusing me is that it was running really rough backfiring and spitting from the carb at different dizzy settings and would only run reasonably I.e. long enough for me to check the timing , at high revs 3600 ish.

I found on the strobe that the advance was 50 degrees with vacuum disconnected. This doesn't 'sound right. On a static check there was about 6mm circumferential advance before tdc mark when rotor and notch aligned, on a 170 mm pulley does this equate to 40degrees? I know this is long winded and probably crap but can someone offer some advice.

Cheers

[kevtherev]

Van was going good with only a failure to idle at junctions issue.......Bromyard carb job and all ignition components in good order.

possible anti dieseling valve issue, inlet airleak.

checked timing at 3600 rpm

Seriously..
This may be just a process of elimination.
fuel delivery... pump and pushrod wear
fuel mixture... air getting into the inlets side to weaken the mixture. Mixture set wrong.
Does the choke flap open fully?
is there a 3mm gap on the flap when cold?

Now you have messed with the timing with no tickover, I would suggest static timing to get it in the ballpark.

Remember a cold engine will rev due to the fast idle mechanism.. warm it up first

[Woody49]

Thanks, Kev.

Fuel pump is electric and delivering ok ... Maybe too much!
Choke opens fully but the best idle I got was at 1200 revs yasterday and was no where near stable or even repeatable.nd
Mixture was set by bromyards only a couple of weeks ago and I don't want to touch the carb if at all possible.does not appear to be a 3 mm gap though.


As I said I used the strobe and it dialled to 50 degrees advance at 3600 revs, vac disconnected and blocked. This don't sound right.

It basically don't start without easy start and it only runs badly. I had to rush to get the timing done with the engine running.

I don't think it's compression even though one cylinder was down on the others it still had 10 bar.
I don't think it's spark as it runs when it gets going albeit badly.

Air leaks maybe but can they be that significant, maybe. Yesterday when I had it going at 1200 revs advance was about 30 degrees, with vac attached and when I took the vacuum off it faltered before I could seal the tube.


What's best to find air leaks is it carb cleaner.

[kevtherev]

Yes

Eliminate any leaks before you commit to timing
Even a little leak will stall an engine
I know bromyard sorted it but be sure your anti diesing valve works

[Woody49]

Thanks again, I will try to find leaks tomorrow , the cut off valve is getting power and clicks when the ignition is switched on. The carb also worked fine on bromyards van so I don't think that's the issue. Am I right in saying carb cleaner is the best thing to use, and what do I expect it to sound like.

[scunnerd25]

If the carb works on one van it will be set to run on that van which will be different from your van you may have to reset it to run on your van

[kevtherev]

, the cut off valve is getting power and clicks when the ignition is switched on. .

carb cleaner used on an engine ticking over, will increase the rpm if the cleaner is drawn by vacuum into the leaking hose/gasket.
it won't show up a leak in a diaphragm operated component like the distributor, choke pull down or second choke actuator.

Don't guess or assume, be certain, and eliminate