Club 80-90 Forums

Any body got any thoughts/ideas on this. Recently bought a 1.9 petrol van, the last owner told me there was a problem and he had had it in to his local garage many times, to try to fix. Starts fine when cold and sometimes when hot, most of the time it WONT start when hot, it turns over fine, just wont start. First time it did it (just after id handed over my cash) I noticed someone has fitted a filter (cheap in line one) in engine bay before the pump, this seemed almost empty, the next time it wouldn't start that filter was almost full. I know people say there shouldn't be a filter in engine bay, tho I cant see what harm it would do ? The filter by the fuel tank is always full. The tank looks rusty but dosnt seem to leak (had a full tank when I bought it). Runs perfect when running. Appears to be very good on fuel ? The garage has fitted new leads/plugs/dizzy cap/ ignition thingy on n/s engine bulkhead,new coil, said theyd fixed small air leak, aa thought it was problem in carb, they stripped it at road side. None of this has helped. Any ideas, before I look would be appreciated .Thanks

Do you follow the hot start method described by VW?


maybe the filter in the carb is blocked.
Has the CO been checked recently?

Might be worth trying an electric petrol pump.

marlinowner wrote:Might be worth trying an electric petrol pump.

Could well be. I had loads of problems (well not loads it just seemed that way) with first a dodgy fuel pump but (easy to check) a knackered fuel pump push rod. It was just about long enough to pump fuel when cold but not when the engine had got hot and presumably expanded a bit. Even when I bought a new one it wore out in about 500 miles so I didn't think this was the problem until I checked it.
If I had diagnosed the problem correctly and earlier I think I would have gone down the leccy fuel pump route. CovKid has put loads of info on here how to do it.

I'm one of many that went electric. Its amazing how many 'unexplained' faults with bad starting, spluttering, kicking-back randomly and suddenly conking out is wholly down to fuel delivery. Often spark, particularly leads, is thought to be the cause and its only when you switch to an electric pump that confidence is restored.

I'm a big fan of the mechanical pump (or was) but new ones are nothing like those originally fitted by VW and its a lot to expect from a mech pump to draw fuel over such a long length of pipe. Better by far to have a pump that can keep up under all conditions and prime the line quickly if you ever run out of fuel.

Lust look up 'Facet' on here and you'll find plenty. Price marginally cheaper than a mech one.

I used to have hot-start probs too. Not any more.

Hang on...
a carb has a float chamber full of fuel when you stop, it should start from the float chamber fuel supply even with no pump fitted.

if we assume fuel, hot its starved of fuel or flooded, if flooded you would probably smell it.
have you pumped the accelerator to add fuel?

Tried taking the carb top off and adding a table spoon or so?

while the top is off check the accelerator pump is working!

looked for obvious air leaks

itchyfeet wrote:Hang on...
a carb has a float chamber full of fuel when you stop, it should start from the float chamber fuel supply even with no pump fitted.

true but if the bowl is not full (due to whatever) then it would sometimes struggle until the pump can fill it?

kevtherev wrote:

itchyfeet wrote:Hang on...
a carb has a float chamber full of fuel when you stop, it should start from the float chamber fuel supply even with no pump fitted.

true but if the bowl is not full (due to whatever) then it would sometimes struggle until the pump can fill it?

Ok so to test take it for a blast down the motorway if pump is working it won't hesitate , off the motorway and stop immediately without idling for long (in case air is being drawn in on idle) , then try starting hot.

Thankyou for all the replys. There was a few things that I didn't mention as I didn't want to put people off reading a long post. When it first happened I was convinced it was the pump(as filter was dry), 2nd time it wasn't tho, the guy had told me he told the garage to replace the pump but garage refused as there was nothing up with it.
First time it happened, I took the carb top off (plastic) and droped a bit of fuel in, went for about 4 secs then died, I driped a bit more in same again, next time it did nothing it was just turning over (fast), the guy said leave it for a hr and it will be fine, did, still wouldn't go, so I said push the f---king thing down your drive and il have it transported back (307miles), thought as a last attempt bump start it(while pushing it down drive), anyway it went then ,don't know why, anyway backfied a little for 2 mins, then perfect, drove it 187 miles had to go toilet, so left it running (locked) at services, run in did my business run out, still running, so run back got a burger, run back, tw-- had cut out, started it run for 5 secs wouldn't rev then cut out, wouldn't start then for 1hr or so, then started before rac arrived, drove home perfect for 120miles.turned it of up drive, resarted ok straight after. It used approx. £45 in fuel for 307 miles, which seemed good ? tho the colour of the exhaust didn't look like it was running lean.
Kev what is the vw hot start method?
Itchey feet, are you saying run it till its hot, don't let it idle, then see if it starts straight away? Couldn't see any air leaks, ive noticed someone has bodged, a patch on top of the carb(plastic) which has seemed to have lifted a bit, tho I cant see how that would make a big difference.
Ive yet to look again since its home. Thanks

"the guy had told me he told the garage to replace the pump but garage refused as there was nothing up with it."

So, have you confirmed that pump works and is lively? I'd start there. You can check by pulling fuel pipe from carb, putting the end in a jar and getting someone to crank the engine over. If its weak/spluttery, it may not be enough. Could also be sticking float valve or anything else that causes float bowl to run low/dry. You have to work through and rule out potential culprits in order to pinpoint cause.

I should add, an under-performing pump is rarely consistent with sometimes hours of trouble-free driving then probs etc with no real pattern.

Another thing to consider is water in the petrol, as you say the tank looks rusty. Do the test to watch the petrol output from the pump, collect the petrol in a jamjar, let it settle and look to see if there is any water which will separate out and lie below the petrol. If there is, water is either getting in though perished rubber at the filler, or through rusted holes in the tip of the tank.

Could it be a vapour lock, lean engine running to hot, boiling fuel in the float chamber as temp rises when engine is switched off, would answer why there is no fuel in the inline filter. Have a sniff of your air filter next time it happens shouldnt be too petrolie (if petrolie as a word exists)

From memory hot start is foot flat on loud pedal until it (eventually) fires.

Mine runs sweet as a nut all the time apart from the extended cranking when hot.
Going to get an electric pump, thanks for the info CovKid.

thanks for the replies, I was going to try and test pump (put pipe in bottle) but was reluctant to do it, in guys drive or at services as I thought it may be a bit risky, as I had hardly any tools with me, didn't fancy petrol going every where. I did think about the float valve getting stuck, but couldn't see why it would do it only when hot? same with water in fuel i would have thought it would have running issues both hot and cold? Engine runs cool, on gauge anyway, at about a 3rd on gauge. Ive not looked again yet since I drove it home, I was just gathering peoples thoughts before I looked . I was thinking of comparing fuel flow from pump when cold and when hot first. Cant see it being electrical due to the parts that have already been replaced, cant think of any other electrics to check. Thanks, any more suggestions will be gratefully received.

None other than those suggested.

If its any help, I used to have a really annoying prob before I went electric whereby if the vehicle sat even for a minute with ignition on after a run, it would refuse to start (fire). I used to have to sit there for a few minutes with ignition off and then it would go.

This stopped happening when I fitted an electric pump although I have no idea why.