sudden lack of power?

[captain hairy]

Hello, I live in Pa near philadelphia and this is my first samba. I am the proud but very often confused owner of a 1990 Vanagon gl automatic. I bought the van months ago and have been plaged with problems ever since. Don't get me wrong I love this thing and will not stop until I can call it RELIABLE.
Here is a quick list of weekend projects reciently carried out on this van.
Completely new Brakes front and back. front rotors, rear drums and cylenders. a bear of a coolant pipe, and two cubs. Oh yea, a new transmission. I think I was trying to forget that whole experience. I'll stop boring you guys and get to the point. I thought I was just about there. You know RELIABLE when I experienced a sudden lack of power driving home from work one night. I have one of those air flow meter corection things and it is't a sporatic problem. I cant seem to get the rpms over 2000 in forward or reverse. In neutral however there doesent seem to be any problem at all. Why would that be.
Thanks for reading. Hope to hear from you. They just reopened an old drive in movie theater near us and I'm hoping to pile the family in my VW and try to catch a show befor the summers over.
p.s No spell check hugh. sorry I forgot how to spell years ago

[weinerwagen]

I'm guessing albeit with a spell check,,,,,,fuel pressure, vacuum leak somewhere and or a possible cat obstruction.

Fuel pressure is critical. Make sure your filter is new, and the pump is up to 60-70 lbs or more pressure. (They are cheap and easy to replace)

Make sure the fuel regulator is not spewing gas everywhere. Make sure all vacuum connections are tight. Idle the engine, use carb cleaner and spray ALL connections...(don't set the baby on fire though, that is a pisser when that happens)

Make sure the vacuum advance is not blown out. With the engine off, take a draw off the port side of the vaccum advance and see if the diaphram (ladies I used it correctly) is now blown out!

When it loses power, check to make sure the gas cap is not so tight it causes a vacuum in the tank...(rare).

When it loses power, make sure you are getting proper air flow thru the exhaust system. If the cat has taken a dump, they will shut down air flow, but....it should be obvious that the engine is straining against the obstruction...

Make sure the O2 sensor is new. Another cheap repair.

When it somes to the MAF, now I'm out of my rhelm. I have several I keep around for spares. I snag used ones at the self serve junk yard.

Recap: (Damn weiner you repeating all this stuff??)
fuel presure has to be up to snuff
no vacuum leaks
no obstuctive exhaust
no busted vacuum advance
no mother in laws stuck in the flywheel
and, no Toyota or Nissan parts at all or the Kraut will toss a tan : roll: trum you haven't seen since a suger wired 5 year old at Target!
_________________
Retired attorney--Tort King.

[captain hairy]

Thanks for the check list. I'm going to start with the cat first. The whole exhaust system looks like the tin man pre emerald city. If you think of any thing else to check let me know.
I hoped this would be a good info web site. And i'm realy impresed so far.

Thanks again

[TeamSpatula]

You're not alone... my 87 Westy is going through something very similar...so far I have checked fuel pressure, vacuum leaks, timing...it's probably something small, it's just a real pain to find it...good luck...I'm still looking.
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[obus]

hey captain Hairy, if all else fails go to see Ken Wilfy down in the vineland,nj area. he is a Vanagon master! he helped me back when i had my vanagon. go to vanagon.com
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[vwtom_ia]

Did you get this fixed yet?

If not - what happened to me once was the air intake collapsed. Leave the van running and go back to the engine bay. Rev it up and take a look at the intake boot. Does it collapse when you rev it up?

This is what mine did. What I found was the old intake hose (which is located in the body panel in the right rear corner of the van) had collapsed.

I ended up going down and buying a 3" dryer vent from local home improvement store. I have to oval it a bit with my boot - but I ended up getting it in there.

Let me know if this sounds like it and I can try to give you some more information.

Tom

[Alan Brase]

Well, Weinerwagen, the 86-91 with Digifant do not have vacuum advance. all that stuff is mapped in the Digifant.
I've recently had similar problems with my 91 and am suspecting the fuel pump inlet may be getting plugged with rust from the tank. I think it's time to pull the tank and do some rust proofing and seal/ hose replacement.
Mine just falters at high rpms- sounds like inadequate fuel delivery.
Al
69 doublecab, Vanagons

[weinerwagen]

Man I am getting OLD! Too many cars, too many kids, too many housecats, and too many SUV's on our nations highways getting in the way of my big rig....

You are right Doublecab! I went out back in my workshop, looked at a 2.1 engine sitting on a pallet, YUP YUP no vaccum hose on the distrib!

Sudden loss still leaves me with the feeling of fuel delivery. Electrical outages tend to be sudden and quick acting with a motor. Such as, backfiring, instant shut down. Loss of power in the sense that this thread has indicated appears to be fuel related.... IN my humble, oh so humble, oh so (how did I do on the humble meter?)
_________________
Retired attorney--Tort King.

[TeamSpatula]

[Alan Brase]

I'm talking about the pressure at 70 mph, not too easy without remote pressure guage or chassis dyno. (guy down the street had a chassis dyno, but sold it and moved away!)
Al
69 double cab, 91 Vanagon

[60kombi]

If your van still has the original cat check it! I had a sudden loss of power in my 87 syncro. The cat had melted internally due to a over rich condition. Replaced the cat, fixed the rich condition and all was well.

Mike

[weinerwagen]

One of my daily drivers 1.9's which I use to run back and forth to Phx, AZ acted up this morning on the freeways. Cut out several times like an ignition failure...but the dash idiot lites never lit up...

Turns out to be the micro switches at the T/B were out of adjustment. When I would back the gas off to almost 0, the switches would cut the engine on and off several times like I was losing power...

But, this was a 1.9 not the 2.1...
_________________
Retired attorney--Tort King.

[captain hairy]

thanks for info. I hope to have some time this weekend to do some tests. I may just remove the cat and muffler all together and see if the rpms improve. It shouldn't be any more anoying than the neighbors weed wacker and lawn mower obcession. I like the air intake hose and pre fuel pump clog hypotheses. If these three thing arent the culpret I will probable go seek a good mechanic. That vanagain place in NJ in't too far. The one thing that realy has me puzeled is the fact that the rpms seem to be fine when I rev the engine in neutral but in drive and reverse it cant get above 2000. why would that be? Hope that is a crucial clue.

[DanJReed]

Oh, man,

I just came across this!

Where are you in Philly? I live across the river.
_________________
-Dan
(87 Westy Vanagon, 98 Jetta GLS 2.0, 95 Golf Sport)

[Alan Brase]

Keep in mind that the oxygen sensor is in the catalytic converter. It'll run pretty good without it. Not quite as perfect as with it functioning right, but it really works better to disconnect the O2 sensor if you have a leak in the pipes ahead of it. When my cat plugged up, there was a slight leak and it sounded like there was a giant air compressor under the car blowing off air. ALL the exhaust was forced out this leak.Perhaps it was this leak that had caused the converter to overload and melt to a plugged condition in the first place.
Al
69 doublecab

[mjamgb]

When a FI engine will rev fine but poops out under load, the pressure is usually to blame. Suspect underpowered pump, clogged filter or mal-functioning pressure regulator.

Mike!