injection pump
 

The injection pump on my 300d seems to not be putting anything out on the #1 cylinder. Yes, I pulled the injector, nothing comes out the tube from the pump. It began running rough and blowing blue smoke at the same time. Just had a new timing chain and the valves done, worked good for 150 miles or so and then just started doing this while running at about 65mph. Is there something that could have slipped or am I probably looking at a new pump ($$$$$)?

Been there, done that.

Maybe you can get very lucky like I did. After overhauling my daughters 300D, number one would not hit at all. At first it scared me, thought I had no compression. A compression test showed 370PSI on all five, whew!

I then pulled the line for number one, and removed the fitting at the top. Then pulled out the spring and plunger below that, and then the sleeve and copper washer below that. I cleaned everything very well and reassembled. Number one then came alive. I considered myself lucky.

Do not loosen the two nuts on the plate that surrounds the fitting, you will lose the calibration for that cylinder if you do.

Best of luck,

Unfortunately I already did that, I had a guy that works at a diesel injection shop come by and check it out, he had no idea what could be wrong, everything looked ok to him. He thought that maybe it was getting pressure back to the pump from one of the cylinders but we couldn't tell. The funny thing was that when the tube going to #5 was cracked open it ran smooth and #1 would come somewhat alive, I wish someone could explain this. I'm going to take it by Tyler Fuel Injector next week to run a test on the injectors and try to figure out what's going on.

When I started inquiring about this when I had the problem, it was suggested by one of the pros that I remove the injector and let it spray into a cup while watching the spray pattern at the injector.

Be careful with this, because this high pressure stream of fuel can cut you.

Good luck,

It smoothed out when you cracked the #5 line because numbers 2 - 3 - 4 when firing are a bit more balanced in thier firing order than when #5 is included in this order. Do as Larry has said, and pull the pre-delivery valve assembly from #1 on the injection pump without moving the outer hold downs so the calibration won't be altered. carefully inspect clean and re-assemble the valve to pump in the correct order. Start and run engine without installing #1 injector line. You should have fuel comming from the pre-delivery valve at the fitting for the line. If no fuel, pump is at fault and will have to be repaired or exchanged. If fuel is present, pull #1 injector and switch it with #3 injector, start engine and run for a few minutes to get any air out of lines, if miss changes to #3, injector is bad. Make sense.

Rob

For the sake of safety, I must expand on Larry's previous comment:

If the high-pressure jet from an injector hits you, it will cut you. If diesel fuel gets into your bloodstream, even in a tiny amount, you will die.

"Be careful" is an understatement. Unless you have the proper tools and training for checking injector spray pattern, don't try it. Leave it to the professionals.

- Nathan
'83 240D "Steiner"
'00 New Beetle TDI

There is no, repeat no, high pressure at the injection pump with the line to the injector disconnected. pressure is only built up against the pintle valve of the injector when it is installed in the line.

Thanks for the warning but I'm going to take it to a diesel injection shop, nothing comes out of the #1 tube. If I pull the stuff out of the pump, actually I had a guy from the shop I'm taking it to do it, and put it back together it "spits" a little bit but not as much as the others. Long story short, I need to get it fixed and I want to have it done right, hopefully I'll accomplish this by taking it to a professional. I just hope it's not going to be expensive.

The thing that really still makes me wonder is that when #1 is disconnected from the injector and #5 is cracked open #1 starts putting out some fuel. I can see why it might run smoother but why I start getting fuel on #1........something doesn't make sense.

#1 sleeve set and #5 sleeve set aren't connected except by the camshaft, so I have no idea why you get more fuel when #5 is open.

Sounds like your #1 plunger spring is broken, so the plunger stays up instead of re-filling with fuel for the next injection. Not an expensive fix, but the pump does have to come apart!

Peter

Sounds like your #1 plunger spring is broken, so the plunger stays up instead of re-f
 

Are you referring to the spring which keeps the pintle valve (or pressure valve) closed? The small spring under the 15mm threaded housing?
Or are you referring to the small diameter "piston" underneath the pressure valve which is connected to the camshaft? Is there a spring under this? or is it hooked onto the camshaft?

I guess I need to see a blow up of the pump, huh...

The reason I ask is because I cannot get any pressure on my #1 injector.:rolleyes:

Ed:

Do you get any fuel delivered with the pressure valve spring out? If you do, the seal is shot -- its underneath the steel "sleeve" that the pressure valve and spring fit onto.

If not, you have an internal problem with the pump and will have to have it serviced -- it simply is not possible to do this at home. The two most likely causes are a broken return spring or a scored plunger, niether of which can be replaced without complete pump disassembly and recalibration.

I repeat, it is NOT possible to do a pump repair at home -- if you take it apart, you will have a non-funtioning pump. Yes, I know all sorts of folks claim to do injection pump repairs on the workbench, but I've yet to see one properly working when they were done!

Peter

Peter,
Depends upon what is wrong with the pump. I had injector pump on 1970 220D fail to feed to #4 injector. Rear camshaft ball bearing had come apart allowing the camshaft to drop so that #4 plunger would not operate. A $7.50 ball bearing fixed the problem. This problem occurred at about 200,000 miles---this pump now has a little over 720,000 miles, having survived two short block replacements. When working on injector pump and removing parts a clean work surface is essential. And as has been pointed out, some parts you don't mess with---like the two nuts that hold each holding flange at element assembly (not present on the 220D pumps).

Peter,

Thanks for the input!
I found my problem, there was no seal under #1 injector,(my fault), so I wasn't building pressure...

Now it fires, but only above 200 rpm, hmmmmm.:confused:

Peter,

...that's 2000 rpm!:rolleyes: