New injectors ----> hard start. timing change????

[ericthefish]

Hello All-

I have a 2000 golf TDI 5sp with 128k miles, running b100.

6 months ago the car was hard to start (i.e cranking for ~8 seconds before starting up). The dealer did "something" (which I assume was change the timing) and that + a new battery solved my starting problems- it started right up. I had checked the timing last year (i.e. 6 months before taking it to the dealership) and it was fine (right on the midline on the chart). I did NOT check the timing after the dealership did whatever they did, but it sure solved the hard start problem.

I decided to go for some new injectors, so I bought some powerplus 520's from Kerma, then had them installed in bodies at Lubrication specialist.
I put them in 2 weeks ago, and ever since have had a hard start again (~6 seconds of cranking before it kicks in). I asked Greg if he had any ideas, and he suggested checking for air leaks in the fuel lines. All of the fuel lines are pretty tight (I don't have a torque wrench, but they are about as tight as they were to get off). Plus I don't see any fuel leaking around the connections.

I read up on the forums and found that timing is a pretty good suspect for hard (cold) starts. My car never has a problem with warm starts. I checked the timing yesterday and it is off. It was below the shaded range on the chart.

The timing belt was changed around 80k (by the previous owner) so I haven't touched it.

Before I mess with timing (which I have never adjusted before), I wanted to see if the boards have any suggestions on anything else to check/change. I did do the injection quantity adjustment and the EGR recalibration.

My question is: Is it possible for the timing to change? Is there anything in replacing the injectors (following the procedure from TDI club) that could affect it? i.e. all of the cranking to get it started after all of the fuel lines went dry. One question I have is about injector 3, with the sensor in it. I now have a new one of those. Is it possible that my old one was bad and it wasn't sending the signal properly? Or the new one is bad?

Thanks in advance.
--Eric

 

[doc_m]

nothing in changing the injectors should affect timing, if anything perhaps when the TB was done the 3 bolts on the IP were not tight enough, snug but not tight.

The only thing really is adjusting the IQ which myself like to wait a bit for the new nozzles to set in for a few hundred KM's sometimes there is the slow dow shudder or kinda smokey, so adjusting the IQ up will help remedy that.

And the needle lift sensor should be ok or is it throwing a code?

 

[ericthefish]

more info

As far as I know, the needle lift sensor is ok. How would I check that?

The other piece of info, which I omitted from the previous message, is that one of my glow plugs is going out. I just ordered a new set, which should be here next week. But I live in san diego. It is NOT cold out. I wouldn't think the glow plugs would affect the starting. And the hard starting started with the new injectors. I.e. cold starting was fine with the old ones (although the car definitely wasn't as fast....) and ever since I put the new ones in, it has taken 8 seconds or so.

I suppose it could be a coincidence that the timing slipped at the same time, although I didn't even open the timing belt cover...

The whole thing just seemed a bit odd to me, so that's why I was wondering if I was missing something...

-E

edit to add: The only code the computer is giving me is for the glow plugs, but that just started yesterday. The only time I see any smoke is on these cold startups. I do not experience the slow down shuttler (at least it seems better than the old injectors). I have a can of diesel purge I could try too, but I'm not sure what good that would do to brand new injectors...

 

[ericthefish]

new injector bodies?

Sorry to respond to my own post here, but just one more question- Since I did put new injector bodies on there, with new springs, etc... Is it possible that the different spring tensions are causing the nozzles to open at different pressures (i.e. changing the timing?)

I'm just trying to figure out how this timing change happened.

Thanks,
-E

 

[Canadian_Grizzly]

Eric check your "return" fuel lines...the ones linking all the injectors together. If there is a leak on any of them then fuel is allowed to siphon away from the injector.

 

[ericthefish]

return lines

I actually changed those out with a new set of lines when I put on the new injectors. But I'll double check them the next time I have the hood open.

-E

 

[dieselt]

When you "built" the injectors did you test spray pattern and cracking pressure? Your 520s (.205) injectors should have been tested and shimmed to appropriate cracking pressure. I had mine done at a diesel shop for $30.00 (cleaning , cracking pressure check, spray pattern check). Mine were all within tolerance on the low side. Shims for adjusting cracking pressure are expensive ($5.00/each) and there are over 50 different sizes.

Mechanical timing needs adjustment if you are on the low side of the graph. You have VAG-COM .... the adjustment is not difficult to do.

Why are your glow plugs coming on in southern Cal? Temp semsor problem?

 

[Mad_Dasher]

I doubt this is the problem, but did you use new injector seals that are OEM?

 

[ericthefish]

more info...

I sent the nozzles to Greg at Lubrication specialist to get them installed in injector bodies- So I didn't adjust them at all. I just pulled the old ones out and put the new ones in. I still have the old ones (I haven't sent them to Greg yet). But he should have done all of the pop testing, etc.

I used the injector seals that came with the nozzles (which I assume are OEM).

Is it possible for the metal part of the injector return lines to have a leak in it? I don't see any fuel anywhere, but maybe they are allowing air into the system somehow? I.e. I have a bad injector body. Is there an easy to way to check for this?

I'm going to redo the timing, I'm just trying to understand why it is off...

My glow plugs come on for just a few seconds. I actually have a spare temp sensor I could install, but last I looked (again, a year ago), both temps coming out of it looked fine. I'll check it when I get home tonight.

-E

 

[mojogoes]

It sounds like your timing is retarded some how....if the new nozzles/injectors brake/opening pressure's were changed i.e upped to a higher pressure then yes this will cause your injection timing to be off/retarded.

But depending on how far out/retarded the static timing is will effect how much the ecu has to compensate to make timing run something like.......you will be able to see how retarded it is if you go from measuring blocks into basic setting for timing , if you see the engine note change (flutter or in extreme cases stall out) your static timing is way off , if like in my case you switch back quickly enough everything goes back to normal.

I would say in your case though that if you have enough adjustment on the 3 bolts on the ip to advance timing to above the middle of the graph around a number of 65/68 .....if like in my case there is no adjustment you will have to jump the pump a tooth in the direction of the front of the car.