Rebuilt Pump, RUNS AWAY!

[kingler5]

I just finished resealing the pump on my Golf 1.6 TD, engine code MF, got everything put back together correctly (I think), retimed etc. Let the pump suck ATF thru the fuel filter to speed the process of bleeding. Finally got all the air bubbles out, and the instant the engine clattered under its own power, it accelerated itself nonstop to some really hi-revs. Never had any issues like this before, and it has a new head gasket and less than 150,000 miles on this engine, so I am leaning towards an error when I reassembled the pump.

Another thing that may or may not be related is that while cranking for about the 60 seconds while I was priming the pump, I mistakenly left the injector lines connections loose on three out of the four lines on the back of the pump coming off the pump's head.

Is it actually possible on these things to crank too hard, too fast and have too much residual fuel in one or more cylinders that could cause runaway? In which case it would be like a "flooded" gasser engine and you would leave it for a while to evaporate. I would think not with these diesels, but can that happen?

My best guess is that I did not put back the max fuel screw to it's original setting. I will check this later.

What other sorts of newbie errors can be made when reassembling a TD pump? I am hoping this is a simple error I made when reassembling the governor/accelerator assembly.

I also remember having a great degree of difficulty(about 2 hours worth) installing the springs back on accelerator, but I thought it looked correct according to my reference photos, and the spring tension and pedal effort felt normal.

Thoughts? THANKS! This place rocks!

[burn_your_money]

You can't flood a diesel.

I would look at the max fuel screw and the throttle assembly. Did you mark the throttle lever in relation to the shaft before you took it all apart?

[92EcoDiesel Jetta]

Did the key shut the engine off? If it did, you messed up with the throttle position. Take it apart leaving the springs off and put the throttle midway then start engine and turn throttle down to correct idle, mark the position then put the springs back.

[veedubcanuck]

You can't flood a diesel.

 Actually not quite true... If you keep cranking it with it not starting... say your GPs are not working and you crank it long enough it can cause pooling of fuel causing the engine to race up for a second when it does catch. After all it is injecting fuel the whole time it cranks. The rev is short, maybe just enough to alarm you. Not likely to over-rev though..

[burn_your_money]

Well the fuel is still atomized so it should all (mostly) just be shoved out on the exhaust stroke no?

[kingler5]

Did the key shut the engine off? If it did, you messed up with the throttle position. Take it apart leaving the springs off and put the throttle midway then start engine and turn throttle down to correct idle, mark the position then put the springs back.

Yes, the key shut off the engine, but it was not immediately. I thought I got it right, if it were off though, wouldn't it be off just a tooth or two? In that case if it were forward wouldn't it just idle high as if someone had their foot on the accelerator? And if it were "retarded" I don't know what would happen, would it not try idle too low and just not start? Is it a case where the load compensator goes way overboard?

[kingler5]

I just got thru taking off that splined plate on the top that actually does the "grabbing" on the accelerator shaft, and to make things easy I merely turned it upside so could turn it freely by hand. It seemed to have the correct range of motion, about maybe 45°, but I couldn't get it to turn and fit onto the lever in its original position before teardown which can be seen here http://s272.photobucket.com/albums/jj171/foxphoto91/VE%20Rebuild/?action=view&current=100_1153.jpg In the picture you can see that the shaft seems to be lining up on the left side as you look at it at about "10 o'clock" or the second mark down from the uppermost lefthand marking. I've noticed that pictures I've seen of others' pumps are set the same way.

It seems more like when I turn it to "idle" or at least minimum aka fully clockwise that the slit is more like pointing straight up and down, parallel to the front and back of the car.

I tried starting the car with the lever in various positions from fully CCW to CW, and got virtually no change, it still wants to run way up. It puffs out white smoke everytime. I tried playing with the max fuel screw on the back, it still has its factory collar on it, I turned out at least 1.5 turns to see if it would make a difference but nothing much really. Where is this residual fuel screw I keep reading about?

 It starts quickly and with little cranking despite a bit of residual air in the pump/lines so I'm very confident everything else is in order. Could the timing be off enough to cause this runaway? The key still shuts off the motor easily and effectively each time.

 I'm willing to pull the pump off again and open it up if need be to get this corrected, cause I'm uber anxious to see this thing on the road again.

HELP PLEESE

[rabbitman]

The max fuel screw is the residual fuel screw .

Turn the screw out until you have to push the go pedal to start, after that you can play with the idle screw and max fuel screw and get it to idle right and have good power.

[kingler5]

I took the pump back off and removed the top to put back the accelerator correctly, I found it was about 30° clockwise from where it was before disassembly. I found it was much easier to line the accelerator shaft with the lever with the max fuel screw out. Put the pump back, max fuel where it was before, timed it all correctly, primed it up, charged the battery, cranked it and got exactly the same problem as before. Lots of white smoke and completely running away, but the key stops it.

I tried taking the max fuel screw out a few turns. Cranked again, same result, except this time, the engine was more frighteningly resistant to turning off with the key. I took it out even more and still the same. I then tried backing out the idle screw to about where I ran out of thread, still the same, and the engine was yet more resistant to the key shutting if off. This is where I stopped.

I am out of ideas aside from completely tearing the pump down again and carefully looking to see if anything was amiss, or just sending the pump to Giles, but that's an expensive proposition for me right now. Any ideas? I'm out of em right now! \\

THANKS!

[arnold]

Remove the accelerator lever from the pump,then start it and look if its idles normal,you may have the max feul screw out to far so it wont start but then you know where the problem is,turn the screw in until it starts

Did you removed the plunger from the head ? i know the large collar that covers the hole on the plunger (i hope you understand what i'm trying to say ) can be placed the wrong way allowing a lot more feul to go in the head ?

[kingler5]

Did you removed the pump head and plunger for the reseal ?

I removed the head in one piece if that makes sense. I didn't remove the plunger.

[arnold]

I would first try to start without the throttle arm on the pump,move the shaft from left to right and try starting at multiple positions.
If this dous nothing remove the head of the pump and look if someting looks wrong,maybe take some more pictures and post them,there a lot of pump pro's here so maybe someone will notice something wrong

[dankcorey22]

You can't flood a diesel.

Ive flooded my TDI when its running before I throw so much fuel at it its fell right on its face and white smoke pores out, But then all you have to do is cut the key off and start it back up. Just completely blew the fire out.

[burn_your_money]

The sleeve on the rotor, is that correctly engaged in the fulcrum lever?

Your residual fuel screw is what most people would consider the idle screw. It is the one that the throttle arm rests on. Idle is on the side/back of the pump.


Well that's the first I've heard of flooding a diesel... how did you manage to get so much fuel into your TDI?

[kingler5]

The sleeve on the rotor, is that correctly engaged in the fulcrum lever?

Can you explain this in more detail? Which sleeve? The sleeve from the centrifugal governor? Or the control collar "sleeve"? Fulcrum lever? I thought the max fuel screw acted as the fulcrum for the lever.

I am leaning towards the theory that I may have something incorrectly installed something related to the control collar which is why fuel delivery is taking place just fine but its just "wide open".

Your residual fuel screw is what most people would consider the idle screw. It is the one that the throttle arm rests on. Idle is on the side/back of the pump.

The idle adjustment I was talking about was the idle stop screw on the outside of the pump that the accelerator lever normally rests against.