Engine dieing in traffic issue

[Spud man john]

Hi,

First post for me - be gentle

Just came back from the new forest where my T25 played up something chronic on the way down there.

It's a 1988 Autosleeper Trooper 1.9DG watercooled assumed original lump thats covered 120k. Standard stock everything. It is a good straight old van and is in pretty good state of repair, though I suspect I will need the engine out shortly for a refurb of some kind. Its reasonably reliable

However this time, it ran for roughly an hour or so before hitting the mother of all traffic jams on the M25. Temp gauge smack bang in the middle over the top of the LED. On hills, rises to the right of the LED then comes down again, on the flat stuck stationary in pretty strong hot sun, began to rise then the fan cooled it again OK. Never overheated.

Select first, try to pull away: massive hesitance, splutter then dies. Try to restart immediately, coughs and then dies. Coast over to the hard shoulder, wait a minute or two try again , coughs, splutters, backfires and then it will run again. If you then get clear air and a clear road it will run fine. If you are still in traffic, exactly the same thing will happen again, with the backfire apparently clearing it. With it being the mother of all traffic jams, this happened repeatedly for me. I decided i needed the heat out of the van so I limped in to the pizza hut and deliberated for an hour allowing it to cool and it then ran (in better traffic) fine up to the new forest. Then run home for 3 hours sweetly. So far has happened twice, van runs OK in between, perhaps not as smooth as it might be when applying the throttle I guess but I assumed thats how they are!

Number one suspect for me is a replacement fuel pump it has on there which looks like a cheapo replacement. Rod measures correctly. Could it be that as it gets seriously warm its not getting the fuel it needs and/or the fuel is evaporating meaning its mighty lean and thats the backfire? is a electric fuel pump a decent upgrade/worthwhile or am i up the wrong tree? Failing that where do I look next?

All advice gratefully received, thanks in advance

[kevtherev]

Wrong tree.
The fuel pump is clearly delivering fuel to the carb.
If it wasn't then it would run out of steam at higher road speeds.

When the throttle is pressed a squirt of fuel should be delivered into the carb from the accelerator pump.
This allows the revs to rise quickly and smoothly.
Your description suggests this might not be working correctly.
As the throttle butterflies open a big gulp of air is drawn into the engine.
If the fuel delivered is not enough to mix with this big volume of air then the engine will stall.
A backfire is a symptom of a weak mixture.
Accelerator pump diaphragms are included in the refurbishment kit from Brickwerks.

The symptoms you describe are also indicative of a blocked idle jet.
Which requires the carb float bowl to be cleaned out along with the jets
Rotting fuel lines can cause this.

[Spud man john]

Thanks for the tips. I shall look in to that. Adds up - when I accelerate in 2nd or 3rd when its running fine I do sometimes get a kangaroo effect - mechanic told me this is normal on an old van but I did wonder.

I'll have a look myself then look at a carb refurb - thanks again

[Spud man john]

Just back from my latest trip - more trouble!

Changed the accelerator pump and cleaned up the visible areas of the carb with carb cleaner and some redex. Ran it round locally and convinced myself that it was better - seemed smoother and more responsive when accelerating, particularly in second. Ran up to temperature, left it idling after that. Seemed OK.

Then this weekend I have gone on a very nice camping trip a couple of hours up the coast, however it was 26 degrees and I got stuck in a 60 minute jam through a pile up at roadworks. After about 40 mins stationary and stop start, fan came on, engine temperature about 5mm past the LED centre line it sits at when its normally moving but comfortably coming down with the fan and never looking dangerous. Then the problems returns....

Engine idles, but when you try to move away in first up to second it splutters and feels like its gasping for fuel and dies. Since I changed the accelerator pump it now continues running OK and didn't backfire like before - it kept running but it wasn't at all happy and wasn't pulling properly so I didnt push it. I coasted in to a layby , and after my experience from last time, just switched the engine off and did nothing but allow it to cool. After that, I nursed it around the back roads and it ran the 90 mins OK left in my journey. After the trip, it also ran OK back the 2 hours or so (always moving and cooler conditions). it seems to me that in first or second even when its running OK I'm down on power though with no other reference I cant be sure.

I'm thinking of dropping it in to my local indy and having the rest of the brickwerks refurb kit i bought added and the fuel lines changed (cant get hold of my usual vdub guy, think he is out of business). Is there anything more I could prove myself (checked and changed fuel filter too).

I did toy with the idea of plugs/coil/leads too in case its spark not fuel!

[diabolov]

Hi,
Not sure if it helps, but some years ago I had a bike that had similar symptoms would run for a while then miss and fart in traffic then would cut out as soon as I turned the throttle but run again after 15 mins. I thought it was a crud in the fuel tank or blockage in the line. It turned out to be the coil breaking down due to heat.....might be worth checking there. Just a thought.

Regards

Mark

[a1winchester]

Have you tried some of the simple checks?
If you haven't already done so, I would change the dizzy cap, rotor arm, and HT leads.
Another possible fault is the push rod under the fuel pump. This can get 'sticky' in the plastic pump pedestal when the engine is hot. (replace the lot while you are at it)

All the above are relatively simple and cheap to do, and these parts need replacing at some stage sooner or later, so won't be a waste of money.

Check all your fuel lines and particularly the joints. The clips can be cracked / corroded, and the squashed ends of the lines can be perished. I had a tiny pin hole in my fuel line a couple of years ago, and the van would die on me for no apparent reason - different symptoms to yours though. I just replaced the whole fuel line system for peace of mind.

The other thing that is probably due for replacement is the oil breather pipe that goes between oil breather tower and air box. If yours is like mine was, it's a bit squishy by now, and a new one is overdue. https://www.brickwerks.co.uk/t3-parts/t ... bx-dg.html

Incidentally, if you overfill your engine oil, the oil can get blown up the breather and into the carb, which will give similar symptoms to yours, but you can tell by taking the pancake off and inspecting the carb.

[Spud man john]

Have you tried some of the simple checks?
If you haven't already done so, I would change the dizzy cap, rotor arm, and HT leads.

Did change dizzy cap/rotor arm plugs and leads when I first got it. Though from what I remember they were just kampers parts and that was 3.5 years ago now. I might switch those out and keep whats there as spares

Another possible fault is the push rod under the fuel pump. This can get 'sticky' in the plastic pump pedestal when the engine is hot. (replace the lot while you are at it)

Yep done fuel pump and rod

Check all your fuel lines and particularly the joints. The clips can be cracked / corroded, and the squashed ends of the lines can be perished. I had a tiny pin hole in my fuel line a couple of years ago, and the van would die on me for no apparent reason - different symptoms to yours though. I just replaced the whole fuel line system for peace of mind.

Noted - thanks. I was thinking they should be changed anyway on age basis

The other thing that is probably due for replacement is the oil breather pipe that goes between oil breather tower and air box. If yours is like mine was, it's a bit squishy by now, and a new one is overdue. https://www.brickwerks.co.uk/t3-parts/t ... bx-dg.html

Noted again - I was looking suspiciously at those (squidy) pipes too

Thanks Again - thats will keep me going for a bit!

[Spud man john]

Hi,
Not sure if it helps, but some years ago I had a bike that had similar symptoms would run for a while then miss and fart in traffic then would cut out as soon as I turned the throttle but run again after 15 mins. I thought it was a crud in the fuel tank or blockage in the line. It turned out to be the coil breaking down due to heat.....might be worth checking there. Just a thought.

Regards

Mark

Thanks for the help. I've looked through and I haven't actually changed the coil! I think thats a cert for change

[NicBeeee]

As Kev said, you really need to clean out the float chamber and jets before you start spending more money, its always best to do the free things first. Maybe if your local indy is a decent enough guy, then you can remove the carb, split it, take it down to your local and ask if he wouldn`t mind giving it a blast with some compressed air.

Just read you havent changed dizzy cap or rotor for 3 years, normally change these with each service so well overdue

Oh if your local indy is the same guy as the mechanic that said its normal for old vans to kangaroo a bit, alarm bells are ringing

[Spud man john]

As Kev said, you really need to clean out the float chamber and jets before you start spending more money, its always best to do the free things first. Maybe if your local indy is a decent enough guy, then you can remove the carb, split it, take it down to your local and ask if he wouldn`t mind giving it a blast with some compressed air.

Cheers. When I changed the accelerator pump I bought the brickwerks refurb kit. Reckon it would be worth having them fit that while its apart? I'm not sure I'm competent enough so I phoned them (they have been there years and are reputable) and they were confident they knew the pierburg.

I've had the van 4 or so years and done the routine maintenance but other than that I reckon its mostly original - likely that carb hasnt been moved in many years

[300CE]

+1 for a coil problem here. Mine worked fine when cold but played up when the van warmed up. I didn't have any mid throttle at all and had to rev the nuts out of it to pull away and have foot to the floor to move along. The coil was extremely hot to touch.

Replaced this and symptoms went away. Might be worth seeing if there's anyone local to you who can lend you one to swap over and see if it makes a difference.

[Spud man john]

+1 for a coil problem here. Mine worked fine when cold but played up when the van warmed up. I didn't have any mid throttle at all and had to rev the nuts out of it to pull away and have foot to the floor to move along. The coil was extremely hot to touch.

Replaced this and symptoms went away. Might be worth seeing if there's anyone local to you who can lend you one to swap over and see if it makes a difference.

Think I might give that ago as the coil on mine is decrepit anyway

Only fails totally when its really hot and I think it's struggling from the off

[Spud man john]

had the coil off last night and got the multimeter out to have a look

Primary winding is over an ohm, which according to the brickwerks site is out of tolerance. Secondary winding was in tolerance. This is stone cold of course, not sure what will happen once hot

I think I will switch it out. Brickwerks 43 quid JK 31....think I go brickwerks