Vanagon hesitation and cut out

[iweedman]

Hello all. Im back again. Just hoping to get this problem out to as many as possible in hopes of someone having the right solution.

Here is the problem. 1982 aircooled vanagon with low miles on rebuild has lost a lot of its power to climb even slight grades. Not that it had much to begin with but it is less now.

Also, at higher RPM's it begins to choke a bit then starts cutting out quite violently, like it is starving for something: air, gas...?

So far I have replaced the AFM (used), fuel pump, fuel filter, fuel pump relay, cap, rotor, wires, ignition switch, distributor vacuum (used), head temp sensor, air filter, misc vacuum hoses and elbows.

Still not fixed. With each part replacement the van seems to run a touch better for a moment, then whamo! hesitation and cut out.

It always starts immediately and always idles perfectly. The van never dies at standstill. Stopping and starting it does not help either. This problem is not temp dependent.

I did just notice that one of the large intake boots on the manifold is worn out looking on its exterior. I felt around looking for a crack or break and it seems to still have integrity.

Have new spark plugs that I hope to install today.

On a side (or maybe somehow related?) the headlights seem a touch dimmer than normal. They are H4's with the added relays.

Any thoughts would be helpful.....

Ian

[Ahwahnee]

I know zip-all about air cooled vans -- but assuming it has a catalytic converter I would check to see if it is partially blocked.

Sometimes you can shake them or pound on them and hear the insides rattling around but the definitive test is to measure back-pressure.

I have done this myself using the O2 bung but also (while far from home) had it done at a muffler shop (Midas). They simply drilled a hole upstream from the cat and measured the back pressure. When done the hole gets welded up.

Another indicator of a blocked cat is a change in the exhaust note from what it was before.

[Randy in Maine]

Is this a CA or "49 state" van?

[hdenter]

What about the fuel pressure regulator?
_________________
'79 triple white convertible bug
'84 sunroof vanagon
'85 weekender

[Randy in Maine]

And keep in mind we replace no part until it test out to be bad or you will be chasing your tail.

[iweedman]

Randy~ The sticker on the door for this van says Federal. However the fuel pump relay is a 13 pin. Am I understanding correctly that the 13 pin is usually on CA? This can however has lived and may have been initially purchased in CA.
How else can I tell if this is CA or federal?

Hdenter~ The fuel pressure regulated has not been changed but a fairly recent fuel pressure test revealed appropriate results during a drive test.

Just put new plugs in and the problem still exists. Man is this frustrating....

[iweedman]

Good point Randy. I'm certainly chasing my tail here. I wonder if it could be the AFM still? Or perhaps it's wiring harness? Do you at anyone know how I can test these? I did get a new (used) one but I suppose it could be bad...

[hdenter]

First of all, do you have the Bentley Manual? It has a test proceedure for all the FI components. Second, your engine has a lot more in common with the last years of bay window vans than it does with the majority of vans here that are water cooled. You might get more help on that forum.

Hans
_________________
'79 triple white convertible bug
'84 sunroof vanagon
'85 weekender