Diesel runs but won't rev up.

[vdubspeed]

Fix on page 3!

I bought this little hooligan today for parts but as usual...I tried to get it running AND..of course it still runs...it's a damn diesel! BUT, it doesn't want to rev up. My thinking is that the fuel filter is clogged or the like. The pump is not leaking but apparently the previous owner thought the pump was the problem because there were two more in the car! I have NO history on this car. The battery was from 2006 and was the last bill of sale I found in it.

I wish I had more time tonight to play with it and tomorrow I have to much goin on to mess with it but I plan to pull the feed lines, filter(will replace), and lines to see if they are clogged.

Whatcha think?
http://www.youtube.com/watch?v=E4ExE0HOczo&feature=youtu.be

[theman53]

Lift pump could be stuck. Napa or autohaus has Lubri moly diesel purge, run that or atf the old stuff and see if it frees it up. If not it could be the pump. This is of course running it from a can, bypassing the fuel lines and filter. Let it run until the entire can is in the pump...let the feed and return go into the diesel purge can and run it until it is in there. Shut it down and let it sit a day or 7 and try again.
Also, if it is that old I wouldn't run it without checking the timing belt. It could snap any second.

[vdubspeed]

timing belt looks decent(no cracking)

Not like the diesel I got from the woods that sat 18 years and then STILL ran! The timing belt on that one had been eaten by rats!

I'm actually running this pig on the old fuel. I'll switch to a fresh source with some ATF and see if that clears it up.

Thanks for advice,

Jason

[8v-of-fury]

Jason,

You may find that the pump actually is the problem. Here is a scenario that fits why there is two more pumps i nthe car and the owner suspected pumps. Over tightening of the timing belt can cause premature failure of the pumps shaft bushing.. and that will allow air to be sucked in to the suction side of the pump closest to the pulley. He over tightened everyone of them and had to same reoccurring problem. Fits eh. lol

However being that you havent had any time to do some real diagnosing.. its a hard thing to say. But to narrow it down and make the least bit of work out of everything. Id start with;

• First removing the feed and return fuel lines and putting them in to a fresh jerry can of diesel atf mixture. (Dump the full qt in for a gallon or so of fuel)
• Second after running it for a bit (as this will likely cure your problem) let it sit with that new diesel atf mixture inside the pump for a bit. It will help clean it up in there from all the old gummy fuel.
• If that makes the problem go away then next is to replace the fuel filter and hook the pump back up to the cars fuel lines
• If the problem still persists, then you may have a clogged line/pickup in the tank or an air leak in the feed line from the tank somewhere

[burn_your_money]

Wow that car looks pretty clean. Are you sure it's for parts?

I'm in the clogged filter group. Run it off a jug of diesel and see what happens.

Have you checked the air filter?

The exhaust might be all clogged up too. You could try popping the c-clips off. More of a last resort though...

[J Z]

Just a thought ..

Maybe the previous owners have been fiddling with the orientation of the throttle lever ?
It sounds like something that could occur after doing the governor Mod, if you can not find the right spline.

[81 vw pu]

Have you checked the air filter?

The exhaust might be all clogged up too. You could try popping the c-clips off. More of a last resort though...

^^^^x2 on this as I had the same issue on a 81 I purchased that had been sitting for a few years.
The muffler/exhaust pipe was packed full of walnuts hulls. Would fire up and idle fine but really bog out when you cracked the throttle.
There were a few that came out while trying to rev it,so I knocked a hole in the back of the muffler, fired it up and must have spit 2 gallons of walnuts on the ground.

[regcheeseman]

Before you delve in deep - just check that the correct OUT banjo is fitted to the return line (it is marked with 'OUT')

They can be swapped and it will cause exactly this problem.

The in banjo is free flowing with no restriction, the out banjo has a tiny 1mm hole in it to act as a restriction - fit a normal banjo and it'll idle but not run.

[vdubspeed]

GREAT input guys. I want to add that it has a new air filter on it. I slapped one on yesterday so it has plenty of incoming air.

Hopefully today after I get home I will have a second to look at it. I must say I'm pretty proud of the little guy. Almost cranked this morning and it was 38 outside. Probably would have done it with a warm battery. I will shelf this engine once I get it fired up because it's getting hard to find good running 1.6s anywhere down south.

As for the car itself...it does have potential to be a driver again. I almost hate to kill it BUT I want the parts more than I want to sell it. I could probably only get $500 at BEST for it and I know it's worth WAY more in parts. Also...it's a good 10 footer but the paint job was done at Matco and it's bubbling/rotting all over the place.

More to follow.

[Alleslowbuged]

Hi,

i have had that scenario a few time and the problem was allways the LDA pin, which was ticked on his o-ring.
It that is the reason, don't worry it can be fixed in 15 min.

Remove the LDA cover and than remove the LDA pin and look into the guide rail (of the lda pin) and move the accelarting
lever. When you give "full throttel" you must see a small pin down in the guide rail, which moves out of the casing into the
guide rail. If the pin does that, you have another problem, if the small pin is not moving loose the accelarting lever stop pin
(the long M6 threaded bar), so that you can move the accelarting lever as far as possible. Usually the small pin in the guide
rail will move if the lever is moved at is farest position, than reply that procedure and put some grease on the small pin.

Best Regards and luck
Alleslowbuged   

[theman53]

N/A pump

[vdubspeed]

does it matter what kinda of ATF I buy? There are so damn many.

[R.O.R-2.0]

does it matter what kinda of ATF I buy? There are so damn many.

the cheapest kind. prolly just some universal dexron..

[vdubspeed]

Well first off...it did not have the correct banjo bolt. I switched in a good one (OUT) and at the same time made a 50/50 concoction of ATF/fresh diesel. I got the motor running and it still didn't want to rev up. When the pump had sucked in a liter of the mix, I shut it down to let it sit in there. Hopefully something will break free and she will run again.

More to follow...

[theman53]

Did it have the correct in bolt? Trying to feed the pump with an out would cause problems too.