Help!!! TDI injector pump rebuilt and now I'm misfiring on cylinder two

So I rebuilt the injector pump in the car, I changed all three gaskets plus the the o-ring on the meter thing that's threaded into the top of the head... Now I'm blowing smoke and have a misfire on cyl 2. Fuel quantity is not even either, it bounces between 2 and 5.5 so at least I know it's close but I think it's doing that because of the cyl two misfire... Anyone run into this?
I have a 1998 beetle 1.9

I'm wondering if maybe a piece of dirt got into the injector Wow the line was off. Does anybody know how to clean an injector?

Installed, not much for it, shoot some stuff in the feed line and the return. But reading your post seems more likely it's the pump. What's a rebuild, did you renew lots of bits?

BobnOH said:

Installed, not much for it, shoot some stuff in the feed line and the return. But reading your post seems more likely it's the pump. What's a rebuild, did you renew lots of bits?

Click to expand...

There's a gasket on the fuel quantifier and a gasket on the cover for the fuel quantifier. There's also a gasket in the head of the unit and a gasket on whatever that thing in the middle of the head thats threaded into it...some kind of metering thing I heard... These are rubber o-ring type gaskets... And the pump worked fine before I out the new gaskets in... It just leaked... Now it doesn't leak... But cyl 2 has misfire...

I suspect the OP did a re-seal (not a rebuild).

I'm a firm believer in keeping the work area and object as clean as possible. So, my first move is a good pressure wash followed by blowing off with compressed air. I also use brake cleaner or carb cleaner to finish-up with the cleaning (outside only). I've done several IP reseals with 100% success.

Assuming the IP works okay otherwise (will rev the engine), likely some debris got into the #2 hard line! Likely the injector has all five of the holes plugged. If the IP will not rev the engine, something didn't go back in that spot ....

Below, this thingy in....


Below,, this hole!


Below, commence an IP re-seal with a clean pump and work area..

AndyBees said:

I suspect the OP did a re-seal (not a rebuild).

I'm a firm believer in keeping the work area and object as clean as possible. So, my first move is a good pressure wash followed by blowing off with compressed air. I also use brake cleaner or carb cleaner to finish-up with the cleaning (outside only). I've done several IP reseals with 100% success.

Assuming the IP works okay otherwise (will rev the engine), likely some debris got into the #2 hard line! Likely the injector has all five of the holes plugged. If the IP will not rev the engine, something didn't go back in that spot ....

Below, this thingy in....

Below,, this hole!

Below, commence an IP re-seal with a clean pump and work area..

Click to expand...

Yes- reseal. It's all back together correctly. I even drove it to see if it would clear out. Throttle responds like ti should, even has a little bit of get up and go considering it feels like it's only on 3 of the 4 cylinders...
I was thinking something may have gotten into the injector while the line was off ( I didn't use caps). Is there any way to clean out the injector?
Thanks!

If it's plugged it has to be disassembled. I doubt it's the line. It'd take something pretty big to plug it. The injector holes are on the order of thousandths of an inch. I don't see any "cleaner" getting dirt out.

What does the idle balance look like? A number between -3.00 and 3.00 for each cylinder. Ideally they are all close to zero.

KLXD said:

If it's plugged it has to be disassembled. I doubt it's the line. It'd take something pretty big to plug it. The injector holes are on the order of thousandths of an inch. I don't see any "cleaner" getting dirt out.

What does the idle balance look like? A number between -3.00 and 3.00 for each cylinder. Ideally they are all close to zero.

Click to expand...

I had a snap on scanner and I couldn't find the idle balance... I have my vcds lap top at home so I'll have to look at it tomorrow... I feel like it's getting too much fuel though... Not plugged cuz it's smoking at idle through high rpm.... Wondering if I got the pump contaminated... What in in the pump would make only one cylinder recurve too much fuel? What's the screw in the center on the head for? I replaced the o-ring there too which may have changed something...

The small plug with the copper gasket is where one would use a dial indicator for timing the old way. Maybe the factory still uses it when installing the flange on the input shaft. It sees full injection pressure.

The o-ring on the big three sided plug seals case pressure of 50-100ish psi.

Neither of these would cause only one cylinder to missfire.

If you removed the big plug there's a metal-metal tip seal on the end that also sees injection pressure. It's supposed to be a one time use part but I and others have reused it. If it leaked it would also affect all four cylinders.

How many miles on that injection pump?
Could be something silly like a clogged injector return. Might help to remove that injector, but I doubt you'll be able to see anything. Also not sure how to test an individual injector. Some folks will swap 2 to isolate a problem. Interweb guess either junk in the pump or worn internals.

Good idea about swapping injectors.

The copper seal between the injector and head should be replaced when installing injectors.

Ok, maybe I'll do the swap to verify before I but parts... Sounds like a good idea. .

No offense but a misfire on cylinder 2 and you "feel like it's getting too much fuel" don't really jive. If it's getting too much fuel it would't misfire it would put out more power. It's a Diesel. More fuel means more power.

This is why you need to look at the idle balance. Also, I wonder if the Snap-On scanner is giving you the true reading of what's going on or a generic interpretation.

The fact that you messed with the #2 delivery valve as mentioned in your other thread doesn't mean it's the cause though it could be you reassembled it wrong. I doubt you damaged it. I still think it's more likely that dirt got to the injector.

Again, the delivery valve doesn't meter fuel, it works with the injector to make the fuel pressure in the line drop abruptly rather than taper off.

We see that a lot with diagnosis. It's hard for the typical joe/jane to see the overall workings. We get many more clues on these forum things, sometimes.
Interweb guessing #2 ain't firing and if you do run a balance group it would clearly show that.
How many miles on that injection pump?

BobnOH said:

We see that a lot with diagnosis. It's hard for the typical joe/jane to see the overall workings. We get many more clues on these forum things, sometimes.
Interweb guessing #2 ain't firing and if you do run a balance group it would clearly show that.
How many miles on that injection pump?

Click to expand...

The car has 200k and I don't remember anything about a pump being replaced... I was thinking too much fuel because it smokes pretty bad... But I guess a bad spray pattern would course that too...

They do like to smoke. Loose big pipes often cause smoke, I never understood why. If the injector is not working, could be just drawing in unwanted gasses.
I read you replaced the gaskets with pump in car, increased chance of dirt, but we gotta assume everything was clean.

Ok you guys were right on the injector theory. I pulled out #2 and it was a bit carboned up. I called the dealer thinking I'd just replace it with a new one... But after hearing the $543 price tag for ONE injector, I took out the gunk carb clean and let two injectors soak. I cleaned them and replaced them in swapped cylinder incase the problem was still there I could verify it was the injector. She runs like a champ now. Quantity was at 5.5 before but I set it at 4. We'll see how she runs today.
Thanks for your replies!!!

I'm surprised hosing it with cleaner worked. I figgered it would have to be disassembled.

I wonders if the problem was actually a leaking line?

Anyway, glad it's fixed.

Maybe a very-off-chance combo of carbon fouling with a piece of sediment small enough to go through a clear nozzle but not a fouled one... very unlikely, we are talking very small orifices. Just a theory anyway.
Ir you may have had fouled tips obstructing a few orifices and a piece of sediment lodged in a remaining good hole resulting in a pissy spray pattern and cleaning the other holes had it good enough to run decent. Also unlikely, but possible.
Much speculation haha
Run a strong dose of silver-bottle Power Service for a tank and keep a good eye on her.

Contamination control is critical in fuel systems.

Do a strong dose of PS, etc., via diesel purge method... far more effective!

Seems there are 5 holes in the injectors (0.020" diameter each).

A few years ago, primarily observation, I set-up all four injectors above the engine by flipping the hard lines and let a helper crank the engine over. I was amazed.... nothing but a "fog" when injecting! No dripping, no spitting, no after dripping......

Ahhh good atomization...
One must be careful in such circumstances, you can have diesel injected into you if too close- the results range from terrible to death if it happens.
When you have a sufficient protective barrier, you can observe the multiple streams exit the injector and rapidly atomize out into a fine mist. It's pretty cool.