Club 80-90 Forums

Evening All

Aircooled 2.0...

I have an intermittent problem with our van losing power. The van is fine for say the first 10 minutes but then slowly the revs creep down and the speed follows till I'm doing 40 in 4th... I then pull over, give it a few minutes, start up and its may be ok for a few minutes and then happen again or it may be ok for the rest of the journey.

We went camping 2 weeks ago, problem occurred on way there but we drove back 30 miles with no problem.

Points of note: Just recently had the fuel tank replaced. On start up the revs are quite high but a tap of the accelerator drops the revs down - First question - Is this normal? I also recently have had to jubilee clip the manifold elbow in place as it kept coming loose - Second question - I can't see why it wouldn't be but is this ok?

From reading up today it seems I may have a vacuum in the new tank or a dirty fuel filter. The filter was replaced < 200 miles ago so I'm thinking of discounting this. If there is a vacuum then I'd expect this to be occurring at a fixed time after starting the engine and happening all the time - but it isn't...

Any ideas please?

Happy to get stuck in just need some pointers!

Cheers!

Yes the revs should be high when starting from cold the auto chokes increase the revs while the engine is warming up.
If it is a vacuum in the tank then when happens remove the fuel filler cap if you hear an inrush of air then it is vacuum caused by blocked or incorrectly fitted breathers.
Otherwise it may be a fuel supply problem you need to check how much the fuel the pump is pumping. Disconnect the green wire from the coil to immobilize the ignition the put the fuel pump outlet hose onto a jam jar there should be good pulses of fuel coming out, not just short spurts.

bigherb wrote:Yes the revs should be high when starting from cold the auto chokes increase the revs while the engine is warming up.
If it is a vacuum in the tank then when happens remove the fuel filler cap if you hear an inrush of air then it is vacuum caused by blocked or incorrectly fitted breathers.
Otherwise it may be a fuel supply problem you need to check how much the fuel the pump is pumping. Disconnect the green wire from the coil to immobilize the ignition the put the fuel pump outlet hose onto a jam jar there should be good pulses of fuel coming out, not just short spurts.

Cheers Big Herb.

Went out tonight, definitely no vacuum in tank, broke down 5 times, complete loss of power. I'll try testing the fuel tomorrow.

With the tank being changed is there anyway the garage could have ballsed anything up to make this happen - it seems unlikely but I want to ask before I go back to them with the van if I hit a wall trying what I can do myself?

Well I've fixed the issue and I think found the root of a few other issues too.

Looking down on the engine all looked fine but further investigation showed the servo T piece wasn't connected to one of the pipes. I replaced this part with a new one, replaced the manifold elbow too and the van now runs fine. My knowledge of the name of which pipe it was is sadly lacking...

I also changed the air filter and fuel filter and the van now reaches the dizzy heights of 60mph fully loaded. I even overtook someone on my test run

Rather surprisingly, despite the fuel filter being changed less than 200 miles ago it was gunked up - I'm assuming from my old holed fuel tank.

One question - can anyone tell me what the hose that goes into the air box is called please? Its the pipe with brown tape on it in the photo below...