WBX loss of power problems

[irishbruce]

I am a new arrival here. I have a 1990 T25 WBX. Problems began six months ago with an intermittent loss of power on hills, combined with stalling at lights. I was able to get home (just) and started a round of replacing bits which I thought might cause this. Since then the van has sometimes gone well, but as of today is as bad as ever.
1. Fuel filter at tank replaced. (seemed old but OK)
2. Fuel filter at the carb. (clean)
3. Re-seated the earth from the coil, and replaced the Distributor cap and rotor arm. (This appeared to make a difference for a good while until the problems began to reappear recently.)
4. Replaced the air filter (incorrect filter in there, and the duct was oily)
5. Replaced plugs. Exisitng ones were blackened, but not too bad. They currently look a healthy brown colour.
6. Took off the carb, split it and cleaned everything I could see with carb cleaner and blew through every orifice with pressurised air. It was dirty, but the bowl did not have deposits of crud. Very slight discolouration of fuel at the bottom. Reassembled with new gaskets. Started to use a fuel additive which seemed to help - but maybe I was imagining things.
7. Replaced the pushrod on the fuel pump. The old one was a couple of mill short.I have ordered a new fuel pump, as the existing one is original.

I haven't replaced the HT leads - but probably should for the sake of completeness.

As of today, the van starts from cold reluctantly. Choke appears to work. Idles for a while but then stops. The van will drive, but intermittently will lose power - including torque under acceleration and on hills. Stalls at lights when hot and is the devil to restart.

Wisdom needed. Any ideas of what I could attempt next?

[kevtherev]

the intermittent nature would suggest leads or coil.

Check for spark when the engine will not start
Is the coil getting hot?

Does the choke pull down unit work ok?
Are your Vac lines air tight?
Does the distributor advance ok?

[SamsBus2012]

Have to agree with Kev (in my limited experience).
Had loads of similar problems to this over the past year or so and systematically working through was the only way to solve as Kev recommended to me.
I ended up replacing ALL the vaccum lines inlcuding:
the flexible servo pipe off the inlet manifold (can be hard to get hold of but available from brickwerks)
vacuum advance from dizzy to carb
vaccum pipes on carb itself (front and back)
pipes from carb to air cleaner assembly and beyond to the air intake box (apparently you can do away with these and blank off the pipe at the carb if you want).
After this my problems have been largely cured and it is a cheap and easy fix - the pipes may look ok but if they are as old as the van then its highly likely they have gone porous and it is amazing how much even a little leak can affect the running.
Don't discount the coil though.

[kevtherev]

Assuming of course, you have a DG 1.9 Mr irishbruce!
you dint say.

[irishbruce]

Yes indeed kevtherev it's a 1.9 DG

Just completed installing the new fuel pump. Looks nice but the problem persists as per a drive to see if things had improved. Specifically,
Started OK and settled to an idle.
Revs dropped and engine stopped. Restarted OK. All the above within the first minute or so.
Took it for a drive. Seemed to be running well. 10 mins in with engine at normal temperature, I accelerated away from a junction, and everything died. Pulled in hazards on. Had to crank away for a while but eventually restarted. Drove apparently normally for another mile or so. Again, pulling away at a junction after idling for a while waiting for a gap in the traffic, the same thing happened.
Noticed a hesitancy in power uptake.

I have replaced the flexible pipes on the vac lines, but not the lines themselves.
Coil does not seem to be getting hot, but I suspect it's the original unit.
Haven't replaced the leads as yet.
How do I check if the distributor is advancing OK? Might it be seized?

Thanks for your insights.

[itchyfeet]

Yes indeed kevtherev it's a 1.9 DG

Haven't replaced the leads as yet.
How do I check if the distributor is advancing OK? Might it be seized?

Thanks for your insights.

Got to be worth trying different leads and coil
when you changed the cap and cleaned the earth it got better so you would have disturbed them
need a timing gun to check advance and retard

Maybe also your 12v feed to the coil is bad, if that goes high resistance the spark will be weak
To test this theory you would need to add a 10A fused temporary 12v feed to the coil from say the stud in the black box, ignition switch can cause this as well as bad connections or broken/corroded wires

where are you? Somebody may be able to lend you some parts to swap save buying it all and finding it didnt help

change one thing at a time or you wont know what fixed it

[irishbruce]

Thanks itchyfeet. I'm in Northern Ireland near Belfast if anyone else is watching this.

Off to pick up a set of leads tomorrow.

[kevtherev]

Thanks itchyfeet. I'm in Northern Ireland near Belfast if anyone else is watching this.

Off to pick up a set of leads tomorrow.

Be sure to get the right coil too, if you get the wrong type, you'll never know if it would have fixed the problem.

[irishbruce]

Hoping GSF will have both coil and leads.

[irishbruce]

kevtherev you obviously have a story to tell about getting the right coil for this engine set up. GSF didn't have the appropriate part. VW Heritage show several, ranging from £25 - £70. Any recommendations? What's the difference between a Black and a Blue Bosch?

[kevtherev]

Is there a sticker is on your current coil?

Is it green perhaps?

din type or pin type?

what year is the van?

[kevtherev]

http://www.brickwerks.co.uk/index.php/i ... -2547.html" onclick="window.open(this.href);return false;

This is the most commonly fitted coil, pin type Late van.

[marlinowner]

I had problems similar to this caused by water in the fuel, which came to a head after driving down the M6 in heavy rain. Fixed by fitting new fuel tank. disconnect fuel pipe from carb, redirect into a bottle. Disable ignition and turn the engine over on starter until the bottle is reasonably full and see if you have water in there with the petrol. It will form two layers.

[irishbruce]

http://www.brickwerks.co.uk/index.php/i ... -2547.html

This is the most commonly fitted coil, pin type Late van.

Thanks for this kevtherev it looks like the one I should be going for. My van is 1990.

I replaced the HT leads today, and the problem persists.
The engine dies under acceleration but not every time. In fact things went well for about 20 miles and I thought I was sorted, but obviously not.

When getting the engine started again, I need to floor the accelerator. It gradually catches and fires up. Strong whiff of petrol.

Water in the fuel? That sounds plausible. I'll check it out.

[irishbruce]

I had another look at this water in the fuel suggestion from marlin owner.
[
quote="marlinowner"]I had problems similar to this caused by water in the fuel, which came to a head after driving down the M6 in heavy rain. Fixed by fitting new fuel tank. disconnect fuel pipe from carb, redirect into a bottle. Disable ignition and turn the engine over on starter until the bottle is reasonably full and see if you have water in there with the petrol. It will form two layers.[/quote][quote="marlinowner"]

When I split the carb I noticed a small amount of discolured liquid in the bottom of the bowl. Perhaps .5cc? Seems lame to say it, but I'm now guessing this was water. Today, I checked the filter at the fuel tank and saw a small amount of water with the petrol there. Seems conclusive that this is at least part of the problem.

In the short term, does anyone know if a fuel additive is available which might help to deal within this while I look at the possible points of entry of the water to the fuel system? On the latter front, I suppose the obvious options are crack/split in the filler or breather pipe, or (horrors) a corroded tank?