Idle stabilizer issue resolved--LONG

[Piledriver]

Just had a couple of days of nice weather over a weekend and decided to do a little deferred maintenance on the `88 Vanagon. Found a few things that might be of interest to other Vanagon owners...

My 88 Wolfsburg/automatic has ~240K miles on her, burns no detectable oil between changes (OK, IIRC I had to add a quart ONCE) and generally runs fairly well, with a few annoying issues.

(Complete lack of strain relief for the cables on the alternator is next--I just had to get TOWED for that idiocy)

One issue that has been with her since I got her at 207K is that the idle stabilizer has never worked right, and I electrically disconnected it, as it made the idle speed about 3K regardless of any adjustments. This is what I decided to concentrate on...

I ran thru the checkout in the Bentley manual, and the idle stabilizer did the correct hum thing, but still did not work right. It actually worked BETTER if I disconnected the QD in the L front of the engine compartment, but I digress...

The first this I did was google the issue, a fellow had a nice write up as to the engine grounds being funky being notorious for causing this issue, so I went thru all of them, starting with the one on the transmission, then the 6 or 7 little ones under the coil (take the coil out)

I strongly suggest you do this: VW apparently isn't aware that paint is non conductive... and rusty bolts don't work well.

It did reduce my voltage from the case to the body from 240mV to ~40mV, but the idle stabilizer still did not work. I hit all the grounds waxy Pennzoil Marine corrosion prevention spray.

OK, try something else...

I have recently noticed my throttle was not completely closing consistently, and it felt like something was just not right in the throttle body itself, so I ripped it apart. What I found was really ugly:

VW must have had an engineer straight out of school design the throttle body... It has an aluminum body, and an aluminum butterfly, and NO THRUST SUPPORT to keep the (vertical shaft) butterfly centered--- The butterfly had worn 1-2 mm trenches in the body, and had worn itself, as aluminum-on-aluminum wears quite quickly. It was popping up and down into these trenches as it rotated (as it has nothing to hold up the vertical shaft)

Being on an automatic may make things worse, as a 10mm steel shaft several feet long is supported on one end by the throttle shaft, er, butterfly...

Preventing this issue is simple: simply remove the top seal on the shaft, and install a 8mm/5/16? collar with setscrews on the shaft, (adjusted to keep the butterfly centered) over a thin hardened steel washer, and a dab of CV grease to prevent wear and help seal up the psuedo labrynth seal.

I didn't have one of those handy, so I used a razor and cut a small section of 8mm fuel line to exact length, added grease, and placed it under the bellcrank for the same purpose until I can hit a hardware store. In the usual Pile fashion, it will probably be permanent.

In order to get some control back of my idle speed, I filled the grooves in the throttle body with JB Weld afer a good cleaning and degreasing, and even added a sliver to the throttle butterfly... With a little touch up to the butterfly and bore, it all looked good, and is perfectly smooth and centered.

A little shipping tape around a toilet paper roll, sliced down the side, and an appropriate shampoo bottle jammed in the center to expand the "mold" and I had a nice smooth bore after it sat overnight.

Now my idle stabilizer amazingly works correctly, and my idle speed is per spec.

I also did a quick remove/grease/reinstall on my throttle cable, as it froze up on me the other day and I blew my (Fram) oil filter off on startup, while bouncing off the rev limiter at 20F... It'll get a new cable next weekend.

(The only place that can likely freeze is the little ~18 inch section at the back, right before it connects to the automatic//throttle kickdown linkage. Everywhere else it is in ~10mm plastic tubing)

[pocketrocket]

Piledriver, Thanks for the info. on the Idle stabilizer. We need more of this kind of help on the forum. I have seen the throttle body worn so bad that I could not adjust the idle down below 2,000 rpm. Because of the grooves in the throttle body. Im not a JB weld fan but sounds like it would work as long as it doesnt break off & go into the manifold. Rocky