No acceleration - Ferry cancelled - help please

[brookie]

Urgent help required to make ferry for Sunday so I'll be as brief as I can;
Best friend's Van is a 1983 1.9 water-cooled,carburettor with electronic ignition.
Yesterday it developed a major undriveable problem; starts fine and idles ok and is just about ok accelerating up to 20mph but any faster and with any large throttle opening it just wants to decelerate. At same time it sounds very rough, like it's missing on 2 cylinders and will only clear when you take foot off throttle.
What I've tried is following;
Compression test at garage ok
All plugs and all HT leads replaced
Ignition coil replaced
Carb jet checked ok
Carb float chamber checked ,cleaned ok
Vacuum advance unit checked working ok
Vacuum hoses all checked ok
Fuel filter replaced
Fuel Pump and operating piston replaced

What else could I try? It was driving fine the day before and has never had this problem before and it's meant to be on a ferry to France Sunday (having already missed its original booking yesterday)

Please,please if anyone has any ideas let me know asap - many thanks in anticipation.

[T25Convert]

Hi,

Sounds like a fueling issue.

Assuming that you have the original pierberg carb on, have you checked the little brass filter that is on the inlet of the carb? Take the fuel in pipe off the carb, and use a small screwy thing extract the little cone. If its filthy clean and rpelace.

Also, you have repalced fuel filter - was this the one under the van behind the fuel tank? Worth chekcing there isn't another one anywhere else - some people ahve been known to add other un-needed ones elsewhere.

New fuel pump push rod - is it from GSF and if so was it actually longer than the old one, as the one I got was shorter than the worn one I was replacing.

If you take the outlet off the fuel pump and put the end in a suitable container, when you crank the engione (you'll need a helper!) the fuel should 'spurt' out. Anything less than this the issue is on the delivery to the carb, so pumps / lines / filters.

If its 'spurting' then the issue is likley to be with the carb - if its the perberg then search Kevtherev's past posts on this, as most issues have been covered in respect of accelartor pump diaphragms etc.

Good luck!

Cheers,

Alex

[brookie]

Good ideas there and thankyou. Will check that brass inlet cone later today and look around for another rogue filter. The push rod was indeed a longer one so that must be better than a worn short one!
I'll let you know how we get on. Fingers crossed!

[T25Convert]

Hi,

another quick check whilst you are out fiddling:

Engine off, take off the airfilter where it mets the carb, open the little flap you see at the top of the carb so you can peer inside, get someone to press the acc and observe what happens.

You should see a good squirt of fuel appear, and be directed down the venturi. This is the accelartor pump at work. No squirt = knackered diaphragm = replacement.

Ah, and another (sorry for the lack of order, I'm just typing things as they occur!)

You say you have checked all the vacuum lines - have you checked the brake servo hose? Left hand side at the rear, comes of the manifold and dissapears through the firewall towards the front of the van, about the thickness of your finger. Old ones are braided and look fine, but leak like sieves underneath the braid. As you floor the throttle draws in unmetered air, left cylinders run lean, loss of power (and weaker braking as servo not efficient). Quick test, engine running, wrap something like a bit of plastic bag round the hose. If engine note changes you have found culprit. Alternative - get it off and try sucking through it with your thumb over the end. Be careful though as they have steel cable running in them, and can be rather sharp.

Last thought, has this just occurred after a recent fill up at the petrol station, in which case you may have filled up with contaminated fuel?

Cheers,

Alex

[sarran1955]

Hello,

Watching this thread,

Try ^^^^ first, if not cured, then look at ignition again, maybe amp failing under load.

I'm in central France with shade and hookup for visitors...

And a workshop...

Club members always welcome.

Cordialement,

[meridian911]

http://i1242.photobucket.com/albums/gg5 ... c9ceda.jpg" onclick="window.open(this.href);return false;

Have a look at part no7 the little red diaphragm splits sometimes which means the carb over fuels .

[brookie]

Great advice there Meridian and thankyou also to Sarran for kind offer of assistance when in France.
It WAS a fuelling issue!!
Brake servo hose was sound, accelerator fuel squirt good, and the little brass inlet gauze all clear. Checked at BP garage where we'd filled up from emptyish to full 2 days earlier and there was no incident of bad fuel. On your suggestion of a 2nd filter we had a thorough look along the fuel line.
With the engine idling ok we then noticed that the inlet side of the newly replaced filter was half empty whilst outlet was full. The fuel appeared to be drip-feeding from the tank to the filter. I thought this strange as a full tank of fuel would fill the filter up continuaully.
Took the short flexi hose off between tank and filter and found it partially blocked. The rubber lining inside the hose had swollen and was restricting the flow somewhat - ok on idle but up a hill or going fast it couldn't keep up and that's when we get the kangaroo fuel and lack of power.
Checked the tank outlet feed and it pours out - it was simply this hose. Why it decided to swell up like that I don't know.
So new hose on, 15mile test ride at speed and then up Hampshire's steepest hill and all is good!
They can make the ferry now, great result - thankyou

[mm289]

Glad its sorted have a great holiday -

Well done Alex, just what the club is all about

MM

[sarran1955]

Hello,

Glad it is all sorted,

Maybe in 200 miles, go round and recheck all the connections.

Have happy cruising..

Drop in if you like...

Cordialement.