Golf 3 1.9 Tdi cutting out

[hastagrevesz]

Hi folks
I have an issue with my 1995 Golf MK3 1.9 Tdi 1z engine (manual). It's cutting out at random RPMs, more often at lower range, but not only. It does it mostly at operating temperature, but sometimes already at 70°c. It feels like engine breaking, like it is not able to make power. Sometimes it just jerks on the car and still excelerates in short bursts of power, sometimes it needs an RPM change an then its back to normal.
VCDS tells me no fault codes. Start of injection timing is spot on.
I have recently reseated the valves, had the turbo remanufactured (Tho they did not change the wastegate), and cleaned the injectors. Thats when the problem arous.
I have since doublechecked the timing, changed the turbo pressure regulator, the crank position sensor, and reset the fuelpump pressure relief valve. All to no avail.
Have anyone had the seame issue? Thanx in advance!

 

[The Cream Dolphin]

Not a Mk3 guy, but it sounds like fueling to me maybe? What did you do to clean the noƶƶles? When was the fuel filter changed last? Though it seems odd it came up only after significant work, probably not the filter...

 

[hastagrevesz]

I have dissasembled the injectors, cleaned with breakclean and a rag, then put it back together. Fuel filter was also recently changed.
I'm also growing suspicious on the high pressure fuel pump, as it is the only thing I tempered with duringthe last wrenching, and it got a bit worse. Now it is cutting out cold too. It seems to act up when I slamm on the gas while it's lacking RPM.

 

[Steve Addy]

Verify fuel flow to the injection pump is without any air bubbles.

Steve

 

[jhax]

Check the hose inside the ECU that goes to the MAP sensor, probably could use replacing.

 

[turbodieseldyke]

Check the hose inside the ECU that goes to the MAP sensor, probably could use replacing.

That doesn't usually kill the car, only make it limp.

 

[KLXD]

Yeah I like an intermittent loss of fuel too. Either an air bubble or a momentary electrical bubble causing it. So to speak.

Intermittent electrical faults are hard to find. Good luck.

 

[hastagrevesz]

Hey everyone, still here, still struggling. It's time for an update on my situation. I'we had the high pressure pump and the injectors professionally rebuilt. The ecu is a complete other one with the little hose inside changed to new. I replaced the fuel filter, cleaned the pickup in the tank and bled the entire fuel system multiple times now. Despite all that, that rusty pile of doodoo still does not cooperate. However it developed a new symptom. For the first kilometers it acts like its fine, and even than it only cuts out annoyingly. However, if I let it cool down and drive it the same day, it is unusably bad. I let it sit a day or two and it starts over. And it never cuts out in neutral, only under load. If anyone had a suggestion, besides setting it ablaze at this point.... it would be greatly appreciated!
Thanx

 

[HardToHandle]

Is there any exhaust smoke when it cuts out?


Also, if you are going to set it on fire I suggest filling the tank up with gas first so it will ignite easier

 

[braddies]

How about throwing a crank sensor at it and see if anything changes..

 

[hastagrevesz]

There is no visible smoke when cutting out. Also I have replaced the crank position sensor and the turbo pressure regulator as a first, lazy attempt to solve the issue.... That worked out well....

 

[Minimim]

I had a similar issue on one of my AHUs. But it wasnt cutting out it was more like stuttering at 1500-2000ish RPM. What i noticed is that at idle the IQ was jumping around all over the place (from 2 all the way to 13) (viewing in VCDS) so i opened up the pump and found a lot of metal and debris in the IP quantity adjuster. I removed the pump to make my life easier and cleaned it and replaced all the seals i could without taking the entire pump apart. After i adjusted the timing and IQ (i didnt take off the little quantity adjuster needle so i wouldnt have to mess with adjusting that. What i did was take the entire QA case off and cleaned it with diesel and compressed air.) it ran like new again.

 

[garciapiano]

Are you using a vented fuel cap? Or is the tank not even venting?

I’m wondering if the pump is pulling a vacuum and then just starving the system.

 

[Houpty GT]

Have you checked your electrical connections? Disconnect every plug on the engine, inspect it visually, then reconnect. In particular, check the shut-off solenoid and the large, round connector above the vacuum pump.

 

[hastagrevesz]

My fellow car guys, good sirs, gentlemen. I'm happy to announce that my problems have been solved and the TDI is cured. After dropping a bag of cash, rebuilding about the whole entire engine, my friend found a tiny leak from the fuel line fitting, that sprayed fuel over the injector, which revealed bubbles between the fuel injector and the head. Yes, the injector holder screws weren't tightened enough. Since I'm a cheap bastard, I did not own a torqewrench, and therefore were too afraid to tighten the screws too much in the aluminum head. Now the only question remaining is, will I be able to drown my shame in alcohol, or will I have to move to Tibet to live as a monk to escape the crippling embarrassment that this has been. However, I would like to thank every single one of you fine Samaritans, trying to help me. It was a journey I will embark on later days because the only thing I'm more than stupid is stubborn!
Thank you and goodbye!

 

[HardToHandle]

It happens

I replaced the injection pump on mine when changing an adaptation would've probably fixed it

In these cases, I adopt the mantra of "at least that's new and it won't be a problem later" to retroactively justify my actions

 

[Tagazou]

I had similar issue and was harness wiring near fuel pump.

 

[KLXD]

I hope that was indeed the problem but seems odd since the injectors have been in and out in the course of your adventure and your symptoms didn't seem to me to indicate a slight compression leak. I would consider a fuel leak a bigger problem but again, was it there from the beginning?

Now that you are finished, are you sure there is only one seal under each injector?