RPM hangs up a bit between shifts

[Harry]

Sometimes, not always, my RPMs stay up a noticeable bit between shifts. Springs on the throttle shaft on the IP look ok. Timing is at 1.01mm. Runs good, just hangs up between shifts and I can't figger it out.

I'm still blowing quite a bit of smoke in 1st and 2nd from a complete stop. Not much smoke when going down the highway. Maybe old injectors or something?

Thanks, Harry

[Ira B]

If the external linkage is all good then maybe the governor or full load linkage (both internals of the IP ) have some gunk or goo on them.
Maybe some Diesel Purge will clean it up.

[82vdub]

pour some engine oil on the large spring assembly on the IP. This can stick. Also make sure your linkage is securily fastened to the IP bracket, and that the cable within the throttle cable is moving and not the whole cable (including the cable and outer jacket). I've also had the floor mat hold down the throttle a bit on some occasions too.

[VWCaddy]

I had a rebuilt pump installed in my old '81 and it would stick open from time to time. I periodically sprayed down the big round spring/lever assembly with penetrating oil any time it acted up. After a few applications of oil over a year or two, it seemed to free up and work fine.

[hagar]

Harru : here at hagars ,that happens to All my Rabbits , cure ? simple , turn Idle RPM down a smidgen..

hagar.

[UB3RATL4Sf00]

Harru : here at hagars ,that happens to All my Rabbits , cure ? simple , turn Idle RPM down a smidgen..

hagar.

Same thing as hagars, mine hangs, but the governor and acceleration handle is fine, I've just kind of accepted it as a 'Rabbit' thing

[hagar]

Harry : the reason VW diesels hang up between shifts ???? , the governor design.

ALL VW Car governors are a "Minimum -Maximum" type. It will regulate at Idle then again at Maximum RPM. .So the band from Idle to Maximum it responds to Pedal input. . SO ? it is not hard to understand that line between Idle and Pedal band is a fine line.-----that is an incredible sensitive Governor , get it ?.

Only a smidgen makes a big difference.. BOSCH also make a "Variable-speed Governor" for this engine..


WHY so sensitive ? The control collar only travels 1/8 Us inch on plunger from Idle cut-off to full Power. EH ?

It has to be. IMHO a very impressive design. Yes we can set Governor speed at Maximum (say 5000 RPM).

hagar.

[Harry]

Well, I really loaded up on the Diesel Purge juice last fill up, about 400 miles ago. Dumped in about 12 oz. Still having the RPMs hanging up a bit between shifts. Springs on throttle shaft are good, but added a return spring extra connected to the throttle arm. I guess it may be the governor collar thing that hagar mentions, I don't know what I can do about it.

Still lots of smoke from dead stop but not bad going down road. Still getting about 48 to 50+/- mpg. So I guess just drive it and look sheepish when someone glares at me for the smoke

Maybe the collar thingey will self-correct with use?

[Fatmobile]

Diesel purge isn't something you add to the tank.

It's something you bottle-feed the pump with.
Full strength.

[Harry]

Uh-oh, what I added, to the tank, was an extra heavy dose of "Power Service". So I need "Diesel Purge", a brand name stuff I guess? OK, I'll go get some. And so you would feed it into the inlet on the IP and have the IP return line go back in a jar or something? And the engine will run on the Diesel Purge? How long do you do it? I've never done this before. Is it ok for the pump seals and such?

Thanks, Harry

[82vdub]

Diesel purge is a brand name and you run it 100% through the IP and return line back to the diesel purge jug. Yes, the engine runs on it and no, it won't damage any of the seals. It's meant to be used this way.

[Harry]

OK, over the week end I will try to get this done, the Diesel Purge thing I mean.

[Harry]

So I ran the 'recommended' 2 cans of Diesel Purge from the purge can back to the purge can, as recommended. I've still got the occasional RPMs hanging up and a gob of smoke making in 1st and 2nd gear shifts mostly.

The RPM issue is so far tolerable, seems to me it makes way too much smoke in lower gears accelerating. Timing is at 1.01mm on my re-check. I'm getting good mileage(49mpg+/-) and good power. If I turn down "smoke screw" even a tiny bit, power goes noticeably down.

Just wishing for less smoke. Maybe weak injectors? They are old. Or is the collar thingey that Hagar mentions on the governor possibly hanging up?

Harry

[hagar]

Harry : Even a brand new Rabbit will "hang-up" like you say .. Here is what I would do in your Moccasins..

Smoke and hang are interrelated. . "Hillbilly-TUNING" is called for. .Turn Full load stop full turn out and adjust pump for optimum . All 3 adjustments are in order. NO TIMING ! . Most likely the pump should be turned 5 smidgens top towards block. . It is normal behavior for that type of governor.

Plunger (piston) and control collar is a PAIR. and numbered. so.

What exactly type car are we talking about ?.

hagar.

[Harry]

The car is an '85 Golf n/a 1.6l, non-turbo, solid lifter engine.

Is The full load stop you mention the same as what I call the 'smoke screw'? OK, so I turn this stop a full turn out and adjust for optimum. What am I looking for as optimum? Less smoke and decent power? And then, turned 5 smidgeons toward the block, is that like timing the IP, nudging it toward the block for more IP advance?

I'm not real expert at all on this stuff, as you can tell.

Thanks, Harry

Ah moccasins. My early years were at Rose Bud and Pine Ridge in the 40s and 50s, father's side of my family.