Engine dying/loss of power - fuel related?

[Andrew1920]

Hi Guys

I'm new to this forum and indeed the new owner of my first VWT25 - 1986 1.9litre petrol 4 speed van with 104K miles. Bought it a couple of months ago and all good up until 2 days ago. The van sailed through it's MOT last week and my wife and I planned our first trip away around Ireland. However, prior to our departure, the fuel gauge was not working and 2 days ago my mechanic fitted a completely new petrol tank.

Please excuse my lack of technical expertise here and I will try to explain the problem which emerged from that point.

We headed off on Sunday afternoon and initially the tick-over sounded low and the first hill we went up caused the engine to briefly flutter and die but it regained its composure and we headed on.
15 miles into our trip the engine stuttered again, a buzzer noise sounded on the dash then the engine lost power altogether. We pulled over, left it for a couple of minutes, re-started and stumbled down the road for a couple of 100 metres before the same thing happened again and again. We had to call the AA and when the man in the yellow van arrived he managed to get the van started with carb-cleaner spray. It ran ok for about half a mile and then the problem repeated this time with very bad 'kangaroo petrol' effects. A second AA operative came out and started it this time with starter spray which kept the van running for about another 2 miles and then it died again. The AA man thought it was either dirt in the carb or the fuel pump had gone.

He then towed me back to my mechanic's garage and the following morning he checked everything and replaced the fuel pump which he said had failed. He then took it out for a test drive for 10 minutes and everything appeared to be fine.

We then headed off again and approx 15 miles down the road, exactly the same thing happened - more or less a repeat performance ending in our van being towed back to our mechanic again.

Has anyone had a similar experience or could anyone advise what the problem might be here?

[Nathanb]

Hi Andrew - I've had a similar sort of issue with loss of power. Went as far as having a full carb rebuild, but I still get loss of power every now and again. Since carb rebuild it doesn't happen as much and if I carry on driving it seems to recover, still trying to get to the bottom of it.

https://club8090.co.uk/forum/viewtopic.php?f=37&t=138626" onclick="window.open(this.href);return false;

My latest idea is to try changing the distributor cap and rotor arm.

Sorry that I don't have a solution. Hope someone can come up with some advice that might help both of us.

[toolsntat]

On my Aircooled engine the pushrod that operates the fuel pump had worn down enough to cause similar problems, so if yours has a rod maybe a quick check may help

Andy

[ghost123uk]

Hi there, sorry your first post is because you have troubles.

You need to get this issue tested by someone who really knows these slightly unusual engine set-ups. When you say = "a buzzer noise sounded on the dash then the engine lost power altogether", this is the worrying bit that NEEDS experienced attention. That buzzer is a warning system to tell you you have no engine oil pressure . However, it sometimes plays up and sounds when the oil pressure is actually OK and a wiring fault is causing it to sound. I hope for your sake that the latter is the case.

Here lies the problem. You need to sort out the running issue, which does sound like a fuelling issue, but you can't keep running the engine until you know for sure the oil pressure is ok, once you know that, you can then address why the buzzer is sounding false alarms.

For some reading see in our wiki THIS, for lots of info, THIS and THIS on the buzzer.

p.s. - The fuel pump and or it's pushrod are a bit prone to wear causing similar symptoms (but nowt to do with the oil pressure warning buzzer), also blocked fuel filters ( see HERE)

Do you do any of this sort of thing yourself, or would you take it to a garage? This is an important question because if you take it to a garage, it absolutely MUST be a garage that knows these vans and engines WELL or they might be stabbing in the dark and charging you for their time and random parts they fit hoping to cure it.. If you are looking for a garage to sort it out, let us know where you are and we will very likely be able to recommend someone near you who can be trusted to sort it out with a high degree of confidence.

[silverbullet]

Dont forget a split vacuum advance diaphragm (inside the metal UFO on the side of the distributor, not serviceable)
I suspect there will be more end more of these failing from old age and they can leak enough air to cause difficult starting, poor economy and the like. Often overlooked.

[ghost123uk]

^^^ true, I have just had to replace mine, though I think failure there would not cause the motor to die, just not run right.

[CovKid]

Add HT leads breaking down to the above.

[ghost123uk]

Or a dying ignition amp, or coil.

So much better to have an experienced eye to check over a van misbehaving in this way, to methodically effectively eliminate one thing at a time until you find the real culprit.

[Andrew1920]

Thanks guys for your prompt responses - lots to consider here and as I am not mechanic at all in any way I am going to run all your advice / suggestions past my mechanic today.
Update to follow.

[ghost123uk]

Where are you?

[silverbullet]

^^^ true, I have just had to replace mine, though I think failure there would not cause the motor to die, just not run right.

Mine just wouldn't start. Mist have gone from a pinhole to a tear and pushed it over the edge.

[123-jn]

First job when it does it is to feel the coil and see if it is hot. Warm like the rest of the engine bay is normal hot is not. Very typical coil symptoms but this would imply that it has failed when the petrol tank was changed which is an interesting coincidence!!! I think I would check the fuel line for blockages if the coil is ok especially the fuel filter and the one in the carb inlet (remove with a self tapping screw). I guess the oil light came on /buzzer because the engine was hardly turning over. Good luck.

[Andrew1920]

Hi Guys

Quick update on where I'm at now. My mechanic troubleshooted the fuel issue down to the fuel filter coming out of the new petrol tank - it was clogged with a small ball of wool type stuff which had got lodged in the fuel line. He replaced this and all was good.

All good until 100 or so miles down the road on the way to Dublin and again, red light flashing and buzzer sounding. I pulled off the motorway and checked the oil level etc. and everything appeared fine. Then, just when I thought it couldn't get any worse, I couldn't get the van back into gear. Had to call the AA and get recovered again back to base.

Next my mechanic replaced the clutch, slave cylinder and hose and I just got the van back this morning. Took it out for a spin this afternoon and whilst it's definitely better through the gears, I'm still struggling to get into first gear. Also 15 miles dow the road, same thing again - oil pressure light flashing and the dreaded buzzer. Pulled in, went for a walk with the dogs for an hour and then drove home again and more or less exactly 15 miles just before I got back to my driveway - same thing again - lights and buzzer.

Can anyone suggest what's might be going on here with:

1. Why it's difficult to engage first gear?
2. Why does the oil pressure light and buzzer sound when the engine gets up to temperature?

Any thoughts / advice would be very much appreciated as my confidence driving this van is pretty low at the moment to say the least!

[itchyfeet]

Difficult to get into gear could be clutch hydraulics nof bled properly.

Buzzer could be bad wiring or faulty switch but you need to get the oil pressure checked hot because it seems to just do it hot, buzzer only sounds when reved above 2000 rpm and oil pressure is below 0.9 bar ( or switch or wire faulty)
Buzzer sensor is under the waterpump and normally closed when running, it has a yellow wire in loom ( brown over engine to loom)

Don't dispair every one of us has been through this initial phase until the years of neglect are put right.

[kevtherev]

Hi Guys

1. Why it's difficult to engage first gear?
2. Why does the oil pressure light and buzzer sound when the engine gets up to temperature?

!

1, I would say the bloke who fitted your clutch has not connected the selector rod back in the same place (is third gear a little stiff too?)
2, hot oil is thin and watery, this causes the oil pressure to drop, if it drops too low then an audible alarm sounds and light flashes.
The wrong oil or old oil will do this, so would a worn oil pump.

do you know what oil has been put in your engine?
Oil and filter must be changed every six months or 3000 miles
I use 20/50 mineral.
I save money by doing it myself