1.6td injection pump fuel screw settings

[Orb95]

Anyone know what the stock setting for the fuel screw is on the injection pump? Just finished rebuilding the motor, but it is having a hard time starting and once idling smokes like crazy. I don't know why it's smoking so bad. I had it turned up slightly before i took the motor out. Just want to get back to basics to start troubleshooting the smoking/starting issues. 

[vanbcguy]

There isn't really a "stock" setting. A pump shop would set it by throwing the pump on their calibration machine and adjusting it till the pump was outputting the amount of fuel the spec sheet says it should. Since you can't possibly do anything like that yourself it's more of a "figure out where you have the right mix of performance, smoke and fuel economy for your needs".

Smoking at idle and hard starting implies incorrect timing, not anything to do with the fuel screw. Is the smoke white? Does it burn your eyes? If so you probably need to bump the timing up. Where is it set to now?

[Dakotakid]

WHAT in the world do you mean by "just rebuilt?"
You mean this engine has just been put together and never ran (as in no break-in).
Or do you mean you have a few hundred intelligent miles on it post break-in?

If it is a brand new engine, you are doing a wonderful job to ENSURE the rings never will seat if you are standing there letting it idle. You just don't DO that.

And, seriously, exactly what do you mean by rebuilt? Some of these guys empty the ash tray and call it a rebuild.

Any engine I rebuild will smoke due to the use of slight amount of lube for the bores and non-seated rings and some assembly lube here and there and all kinds of stuff to burn off in the first 10 or 15 miles.

[Orb95]

Well thank you for the replies. Anyway to answer your questions, it is white thick smoke that burns the crap out of my eyes. I set the IP to 1.00mm as the bentley manual calls for on turbo engines. To answer Dakotakid's questions, yes it is brand new just rebuilt no break in, no miles on the engine yet. As far as what has been done to it, bored and honed for .020 over pistons, new valves, valve seals, valve seats ground and lapped, valve clearance adjusted, gaskets all around, and new injectors. This is one of my first rebuilds and would like any suggestions on how to seat the rings best.

[Dakotakid]

When you let the new rings slide up and down that new bore, without load, you are essentially polishing the cylinder walls smooth. You are defeating the hone.

After rebuild, it is honestly best to only idle it enough to rule out any immense oil leaks, etc. Once that is quickly determined, drive off with the car or whatever vehicle the new engine is in. If you have the option of having a girlfriend or wife or other friend follow you in their car, that is great. It is a nice safety net.

Simply take that new engine and start getting load on it. Throttle up (like on a scale of 10) (like the pain scale in hospitals) to a 7 or even an 8 and let it pull for a few seconds. Then get off the throttle for a bit....and then right back on the throttle, etc. What you are doing here is getting those rings to expand outward from the pistons and allowing them to mate and stabilize themselves in the bore.

Occasionally, briefly stop the car in a safe place and look under it to check for leaks or whatever. Then, get right back in and drive some more.

Not only do you polish the cylinder walls with prolonged idle, but, the rings can actually "migrate" on those pistons and work to align the gaps....which is exactly what you do NOT want to do.

For me, I work on my engines in a community which is at the geographical base of some pretty rugged old mountains (the Black Hills). There are a lot of steep climbs with "s" curves and then down-hills. I take that new engine up there into those "challenging" roads and run it through it's paces to seat those rings.

Goetze rings are so cool, because you can literally feel that engine get stronger within like 10 miles (rings seating) out. I don't have anyone to follow me and there is always a little risk on my end that I may be walking or hitching a lift home if all does not go well. However....it always has because I pay attention to small details in the rebuild.

Don't forget to monitor your temperature and everything else on that initial voyage. It is a truly exciting time!

[libbydiesel]

While taking too long to seat the rings and ending up with glazed cylinders is certainly a real possibility, so is overheating the rings and causing them to lose their temper and never seal.  When the cross-hatching is fresh, placing too much load on the engine for too long can do exactly that.  Short bursts of power with time off the pedal is necessary.  The short burst presses the ring against the cylinder, the time off the pedal lets the ring cool down.  This process should also be done after you have driven gently until the engine has come up to normal operating temperature. 

[rallydiesel]

White, acrid smoke is usually unburnt diesel. Did the injectors come from a reputable source? Did you use new heat shields? Maybe due a compression check to make sure something did it get screwed up on reassembly.

[Orb95]

I found that the IP timing was retarded because iI forgot to preload the dial indicator, so i corrected that, but it is still smoking terribly. Yes, Rallydiesel, I did do a compression test before taking it for it's first test drive, all the cylinders seemed too low, and were as follows when I tested the motor cold:
Cylinder #1 350psi
Cylinder #2 365psi
Cylinder #3 340psi
Cylinder #4 360psi

I did use new heat shields every time I have re-torqued the injectors and have them installed the right way. The injectors are Bosch OEM remanufactured I had my local parts store order in for me.

I took the car out for a test drive today and put about ten miles on it, doing what was suggested, bursts of power, but it is still smoking like crazy. It starts better now that all the air is out of the system, but seems to shutter and bog down as I let off the accelerator and push the clutch in to change gears. It has stalled when doing this, but i assume its a simple idle adjustment.

Is this normal to have this low of compression on new rings? Does this also take more than 10 miles to burn off any assembly lube or oil in from assembling the engine?

[rallydiesel]

Did you measure piston protrusion with the new pistons? Just wondering if the head gasket is the right thickness.

[Orb95]

I did not, I used the gasket that came in the rebuild kit with the oversized pistons from parts place inc. The previous owner did some work to this motor because it has a 12mm Topline mechanical head on a stock VW block, engine code CY . It seems to be an aftermarket head put on at some point, not sure why. I will have to check  the old gasket for the notches

[libbydiesel]

It is normal for there to be low compression before the rings seat especially when the engine is first running.  It is also normal for there to be lots of smoke on a first start and lots of smoke if the air is not purged or there is air continuing to get in the fuel.  Did you adjust the valves?  If not, then that can lower the compression further.

[Dakotakid]

Topline heads are good items. I have yet to hear anyone complain about them.
It is getting hard to find a good VW head anymore. It is probably a rather fresh head.

[Orb95]

yes, libbydiesel, new valves, valve seats were ground, lapped, and adjusted. Just saw that the old head gasket was a 2 notch.... if the motor really needs a 2 notch but I installed the 3 notch that came in the kit would this be the cause of all my problems? Would the motor even run if I installed too thick of a gasket? I guess I won't know unless I pull the head off again.......

[libbydiesel]

It will run ok with a gasket that is too thick but it will add to your low compression.  Regardless, I think your results are probably normal for an engine that has not had the rings seated.  I'd move on with seating the rings and circle back to compression if necessary.  Is there air entering the pump on the supply side?

[Orb95]

Not sure if air is entering the system..... previous owner has rubber lines on everything instead of the clear tubing. Does anyone know where I can get the clear tubing to run to the IP inlet, and between injectors?