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Engine wont accelerate

Posted: 26 Apr 2010, 18:13
by eegdivad
Can anybody help with this one as the cause has so far eluded myself and the man at the garage?
Van is a 1983 1.9 DG.

The engine will start and idle just fine but when I press accelerator the engine kind of wants to stall but doesnt and occasionaly it backfires LOUDLY! The van had been laid up all winter but occasionally started and a few short runs of about 10miles. Then one day it just would not accelerate.
We have checked the electrics; plugs, leads, coil, rotor arm, dizzy and cap all seem to be working fine. The timing has been checked and is fine and no airleak can be identified. Fuel pump and pressure are fine, fuel filter flowing well. Carburettor which had recently been rebuilt (Pierburg 2E3) has been taken apart and seems fine, no blocked jets etc. The garages read outs suggest it is running lean but "dumping a lot of fuel" (not sure what that means). When first started it is possible to rev the negine very briefly i.e. for about 2 seconds before it reverts to idling and will not accelerate again. An oil leak seems to be evident from the cylinder head (Rt side I think). Mechanic plans to investigate cylinder head looking for a failed gasket, valve and so on..is he on the right lines? Is there anything that anyone can think of that we need to look into? I have tried shouting at it but that didn't work :wink:

I appreciate any help you can offer.

Best wishes.

Dave.

Re: Engine wont accelerate

Posted: 26 Apr 2010, 19:20
by kevtherev
I had this problem.
it was caused by a blocked transfer jet.
there is a little pump on the side of the carb it has a diaphagm that pumps a squirt of fuel via a little pipe into the venturi as you press the accelerator pedal.
it's item 14 here
Image

take off the pancake from the carb, get some one to press the acc pedal quickly, you should see a good squirt of fuel going into the throat.

Does the choke pull down unit work?
take off the pipe and suck through the unit if you can suck air then it's shagged
Image

so if that works OK the next thing to check is air leaks, particularly the vacuum pipe to the break servo.
take this pipe off and fill it with water or a solvent to check for leaks
is the non return valve working?

inlet manifold gaskets reseal these or get new ones

Re: Engine wont accelerate

Posted: 27 Apr 2010, 10:30
by eegdivad
Thanks for the info Kev. I'm inclined to agree that the problem still seems to be related to the carb. The transfer jet that you refer to is something I have been concerned about. I am aware that the housing for these come in two sizes (lengths). When my carb returned from being rebuilt the arm that works off the cam on the end of the throttle linkage was hitting the manifold and so 'the squirt of fuel' that you refer to wasn't happening. I had to Dremel a little off the end to allow it to rotate without hitting the manifold. Would having the wrong size unit be a problem?

Thanks.

Dave

Re: Engine wont accelerate

Posted: 27 Apr 2010, 10:36
by jamesc76
Sorry but if you sent a carb off to be rebuilt and you had to dremel a bit off it should have gone straight back to them to be done properly!!!!!

Re: Engine wont accelerate

Posted: 27 Apr 2010, 10:50
by ghost123uk
eegdivad wrote:The garages read outs suggest it is running lean but "dumping a lot of fuel" (not sure what that means).

and

eegdivad wrote:Mechanic plans to investigate cylinder head looking for a failed gasket, valve and so on..is he on the right lines?

Dave, I would recommend to get this to a mechanic that understands these WBX engines.

Look on our "wiki" here = https://club8090.co.uk/wiki/Ga ... 5_Specific" onclick="window.open(this.href);return false; for someone near you, or ask on here for a recommendation.

I agree it does sound like a carb problem or perhaps stale fuel (the unleaded stuff does go "off" quite quickly) - or it could be water in the fuel. But it could be ignition related too, as in perhaps the ignition amp (the little black box attached to the front nearside wall of the engine bay).

I am sure it won't be anything serious :)

btw, remember that after being stood with little use for a while, your hydraulic tappets might take a good long run to settle down.

Re: Engine wont accelerate

Posted: 27 Apr 2010, 11:56
by billy739
have yoy put plenty of fresh fuel in her?

Re: Engine wont accelerate

Posted: 27 Apr 2010, 16:00
by eegdivad
Yeah, just about the last thing i did was to fill the tank up with petrol but it backfired and had little power on the way to the petrol station. After filling up and revving it a bit the problem temporarily cleared and the van drove back home normally , however, next morning is when the current problem reared its head. It made it up the drive and up the road and got about 2 miles before it slowly got worse and then eventually wouldnt rev at all, thus we came home on the back of a truck and since then it has refused to rev.

Regarding the mechanic. He used to be a bit of a Beetle fan and so knows the old Aircooled engine and he has done some work in the past on wasserboxers. He has revised his view on the cylinder head and feels it is very likely the carb but not sure exactly what. The bowl is filling up with petrol, the jet that Kev referred to is apparently squirting well (I've just been up to the garage to check with mechanic). An ideal scenario would be to have another carb to fasten on and see what happens and I am currently trying to locate one.

I agree with hindsight what was said about sending the carb back to the rebuilders but after trimming the arm that was catching on the manifold the engine did run fine ..I've been around town in it, been up and down the motorway at speed in it and all was well. But now I am left with this situation.

Dave.

Re: Engine wont accelerate

Posted: 27 Apr 2010, 18:36
by eegdivad
Toomanytoys you are spot on


Thanks for replying to my problem "Engine will not rev" you were spot on with the little black box i joined the two connectors together and hey presto she will rev again.
I assume the Idle stabaliser unit is the faulty part can you confirm this, or is it a test to prove another part is fuaulty.

Cheers mate

Rennie

I found the above statement in a post titled 'engine will not rev'. It was in reference to a 2.0l air cooled engine. Does the 1.9 DG engine have one of these units? There is a black box at the back left corner of the engine bay with wires coming from it. The van isn't with me currently so I cant check.

Dave.