A hicupping 2.1mv - sdvice please?

[Vdub89]

Hi there; I have a 1989 2.1mv multivan LHD. I am currently having a few running problems with the van; having read the wiki pages I am not really sure where to start or if the problems described exactly match mine.

I have had the van for a few years; and I don't remember having any problems with it after initially getting it up and running again. The main earth wire was corroded and frayed, so this was replaced and the van started. The exhaust system was shot; so I fitted a UK spec exhaust and taking advice from my local VW specialist he cut of the exhaust sensor from the CAT (so it always now overfuels upon start up).

About a year ago the van started bogging down or losing power when driving in heavy rain, I would stop the van and restart if it had cut out completely, rev it until it cleared and then procede slowly on again. This problem has persisted whenever it has rained, with the accelerator pedal becoming un-responsive and the engine sounding like it is flooded and there is no spark to ignite the fuel you are pumping in. I checked the fuel filler cap etc, it was not water getting in. Generally if I drove slow in the rain and sprayed WD40 on the important electricals it could be avoided.

However this Christmas problems have got worse; now in slightly damp and dry conditions the van is losing power and hiccuping down the road. The van can start off fine, then you will feel it judder slightly and then you will feel it hold back and sound like it is flooding. The only way to counteract it is to put your foot flat on the throttle (still in gear) and after a few seconds it will clear and pick up like a train. The problem seems to be worse on over-run, if you are on a continuous acceleration it is ok.

I did change the distributor cap, leads etc around about the time it started cutting out for ones from JK. So I am not sure if I have vanagon syndrome or something simpler to fix via leads etc. I am currently away from home near Dorchester and have a 370 mile drive back to Newcastle. If anyone has any advice on the best things to check first (I have access to some tools so can get new leads and plugs etc if that is worth testing); or even what I can get the RAC man to test to see if my AFM is the problem? Also if anyone knows a good VW T25 specialist near Dorchester, Weymouth or Poole that may be able to help I would really appreciate it.
Sorry for the essay, but I wanted to explain the problem fully.

Cheers

Marcus

[Hacksawbob]

Good starting point https://club8090.co.uk/wiki/Pe ... ittent_2.1" onclick="window.open(this.href);return false;

Simple things to check
Petrol filter, no easy way to check but swap it for a good one if not done recently
remove air filter temporarily see if its the same with out.
Look for splits or loose pipes around air intake area.
check the resistance on the HT Leads resistance OHMS is stamped on the metal end
Unplug ECU (ignition off!) check for corrosion on pins and plug back in. Might be under the back seat? I think this resets it on an MV.
Thick rubber glove on or chunky pliers remove each HT lead in turn with engine running, it should make a difference on each cylinder. If one has no effect then start looking there.
Not sure what effect removing lamda probe from exhaust is, MV relies on this for feedback not just on start up it will probably revert to a saved map like the DJ engine at a guess.
I have a vanagon harness for sale or return if it doesn't fix (+ P&P both ways not inc). PM me if interested.

[California Dreamin]

Are you sure this was a main VW agent who told you it was fine to cut out the lambda probe?
Although MV's will run fairly well when the lambda probe is disconnected they revert to a limp mode......when removing the CAT from an MV it is always best to fit a CAT by-pass pipe (the silencer on an MV is shorter than standard). These by-pass pipes have a lambda boss so the probe can be fitted even in the absence of a CAT (this is recommended)

Make sure you revert to a looped system (with probe)
Check the rotor arm is correct for an MV (it is different)
When the fault occurs stop and remove each plug in turn...I suspect you will find one that is sooted up or wet, indicating a fault on that lead/cap/plug.
Buy quality leads from Brickwerks (there are mainly poor quality after market leads that break down with remarkable frequency)

Martin

[Vdub89]

Hi everyone! Firstly I need to say thank you for all the advice from this post...It has massively helped us out! As my original post stated the van used to hicup in the rain, then at Christmas it got worse and was doing it all day long.

Thanks to the advice I ordered a de-cat pipe from Brickwerks, brand new lambda sensor, new leads and mv rotar arm. I had all these fitted and despite a little exhaust blow (wrong exhaust clamps I think) the van went from Windsor to Swanage and then back up to Newcastle without missing a beat! It took a while to get around to fitting the parts; but I am glad we did as the MPG much improved last week on the way up to Newcastle.

However yesterday disaster has struck once more; we have had heavy rain up here in Newcastle, so whilst driving in it the van started holding back again... idling at 500 revs and only clearing with full throttle after a delay?

This is the original problem I was having in the rain, I just don't know what it is. To dampen the mood further, went to start it this morning and there is nothing on the key, just clicking. This must be related to the electrics surely, both batteries are fairly new and so they can't be flat?

Please can anyone help with suggestions of what to try next or what may be causing this. Also I have two 20 pence piece rust holes under the front windscreen, could it be water getting in here that is causing the problem? Any advice would be much appreciated!

Cheers

Vdub89

[Hacksawbob]

Yes water into the fuse box and earth area below the windscreen on the nearside is a good recipe for general electrical unpleasantness.

[wrongwaysurf]

Hi mate I had a losing power problem on my Ss 2.1 went round and round in circles for months and eventually traced it to idle stabilisation valve. They not cheap but fitted a second hand one and cured problem, good luck ps you can try cleaning them in carb cleaner too but limited success