Author Topic: Is it possible for lda starwheel/pin adjustment to cause these major problems?  (Read 7511 times)

Reply #30January 05, 2012, 02:57:00 pm

burn_your_money

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Yeah try going back to what you initially started at. If that doesn't work, wind the max fuel screw in until power is acceptable and then set your idle. Sounds like you are making progress at least
Tyler

Reply #31January 05, 2012, 03:37:31 pm

R.O.R-2.0

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Sorry I edited posts and might have taken other info out along the way.

I just  Ran a 5 gallon jug of diesel into the passenger seat and ran the return and input line, new seperate lines than were on the car.

Same deal when I go out there cold and initially try and prime the lines.  It pulls fuel rather quick, and within 10 seconds of hitting the starter the car is starting without glowplugs!  So its burping to life to purge the initial air and rather quickly a a solid stream of fuel comes from the bucket, just has other sources initially.  Then its taking about 5 minutes for the constant foam from the return line to subside. 

So it was idling ok and I took it for a drive and it wasn't very long to see the same issues.  Car was hard to get out of its own way, boost is barely trying to build.  Smoky, lack of power and just drove around the corner before it shut off when letting off the throttle.  Did not see the previous pressure out of either the inlet or outlet, no air in the lines. 

Took like 20 seconds of cranking and I got it started with  pedal down, screamed it around the corner again, died and I coasted back to the driveway.  The car sounds like its firing on all 4 during this.

Now one thing I noticed again is as the car gets up to temp on the driveway and I push the advance lever back in that the car might hang on a good idle but it seems to want to idle at 800 on the tach.  If I rev with my foot to just under 1000 the engine smooths out and it doesn't sound like its about to die.

After all these bubbles are purged my return line puts out a steady solid flow which increases with revs.  The lines seem perfectly primed so I let it idle for a while in the car and held the return line up and watched it.  If my diesel can was restrictive I assume within 5 minutes it would have started sucking bubbles and/or start to run rough and see more bubbles in the return but that isn't happening so I assume its pumping.

How would a normal 1.6 td react with idle set to 800?  I know its lower than spec but from what I recall it should atleast stay running and vibrate.  I checked again my locknuts and governor arm screws and they were all as they have been.  Throttle cable is good, everything turns  and returns smooth.

But it does appear when messing with throttle lever at idle that there is a little dead zone. 

I couldn't take that anymore and decided to just warm it up and bump the idle a few turns in to get a hot just under 1000 rpm idle.  Now it seemed to be returning exactly to that spot when I would stab the pedal and let off.  But its night time now and I am too scared to mess with it.

By turbo and boost hoses are all hooked up as well and its obviously not liking these settings.   And my max rpm is still <5000


So I am going to put the lda settings back again to my previous pictures taken for reference before I even cracked it open.

Then I am going to go out tomorrow am like nothing has happened and try and drive the car and hope it magically fixes itself.


Now lets say I keep having these same problems, is it possible that its all flowing and staying primed, but just not well enough for the pump to put out correctly?  Should I then try and inline diesel pump pusher back near the tank?  Hate to waste the money but they have a low psi diesel pump off the shelf at kragen for $60+tax and I need to get back on the road.

Thanks again.

that right there, with the bold text, thats a big sign to me, pointing to issues with the shaft seal..

it shouldnt take 5 minutes to get the return line to quit foaming if you are feeding it off a separate fuel source from the front seat..

i think you have a feed line restriction/filter issue, and a bad pump shaft seal. would almost bet my life on the pump shaft seal.

have you popped the tank open to check the in tank filter?

i believe there is also a check valve on the fuel feed line..
92 Jetta GLI - Black, 1.6D w/ GT2056V turbo..
86 GTI - 4 Door, Med Twilight Gray, Tow Machine..
86 Audi Coupe GT - Tornado Red, All Stock.. WRECKED.
89 Toyota 4Runner - Dark Grey Metallic, LIFTED!

Turbo: exhaust gasses go into the turbocharger and spin it, witchcraft happens and you go faster.

Reply #32January 05, 2012, 08:03:28 pm

damac

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Ok I set the thing backs back to where they used to be but left the fuel screw in the 1/4 turn from my last adjustment.

For whatever reason on shutdown one time I saw smaller bubbles escaping from the inlet and the outlet with pressure.  When I turn the car off fuel immediately runs back to the tank from behind the filter.  I noticed one of the high pressure nuts was letting loose a drop of fuel every 5 seconds so I tightened that up and haven't seen the pressure or bubbles since but there always seems to be a single patch of air after the filter inlet when I come back to the vehicle as well.  Start it up and it draws fuel rather quickly and seems to stay steady on both sides even when reving.

I got a brand new fuel filter I am going to try for the hell of it in a bit.  I replaced the runs going back to the tanks.  I really need to get a vacuum gage on there with everything in the car but I have hesitated just because I had all these problems from the bucket as well.

I went out and drove the car like I stole it, and turning the boost pin just 1/4 somewhat brought the car back to life.  Not quite as much power as I am used to.  The idle and max rpm stoppers are set according to bently at this point.

Now I can start to hear the turbo whine at around 5 boost and it appears my peak reving it out in 2nd gear was around 10, in 4th gear on the freeway with it floored it seemed to hit a wall and the revs stayed low and the boost at around 9.  5th gear was a little more useable with some boost showing when floored.

My smoke patterns are like nothing for the first 1/4 of throttle putting around town.  But if I floor it I noticed as the boost comes on I get the little cloud of gray that is the size of the car which then floats away.  But as it reaches that close to 10 boost the smoke patterns get to be less instead of the constant it used to be.

I never got thick clouds of smoke or black, even before.

As far as the fuel screw I noticed when driving in 3rd gear around town at 3000 rpm on flat ground that if I let off the throttle the rpms would not drop for like 5 seconds then slowly inbetween each tick.  I am not sure if this is an indication that my fuel screw is set right or not.

And the car didn't die once.  Idle for whatever reason sometimes choose to hover between 100 rpm difference, sometimes I watch it slowly rise on its own in about a minute just idling.  Sometimes its lower when coming to a stop letting off, sometimes its perfect.


Any opinion on settings changes at this point that might get my cars original power delivery back, which frankly was pretty darn good and it gets 43mpg with mixed driving, without the smoke?
1985 turbo diesel jetta

Reply #33January 05, 2012, 09:34:02 pm

burn_your_money

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turn your idle down and if need be your max fuel up.
Tyler

Reply #34January 21, 2012, 05:44:34 pm

damac

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I had to leave shortly before my last post, and it looks like the jetta was driven daily since then without a breakdown.

Before I left I had also turned the lda pin to most aggressive and the starwheel a couple turns from the bottom.

With it set like this I noticed some puffs off takeoff from the tailpipe but not the cloud surrounding the car like before, seemed to clear up more on boost.

Boost seems to hit 10 quicker with the pedal floored now and stays there with the stock system in place.  Before it was a typical windup, then the car catches up and you hear the turbo whine and the boost builds accordingly as it reved out.

The car did get allot of its power back, but still a bit short.  For example getting on the freeway in 4th gear slammed it won't seem to rev out to get beyond 60mph like a wall.  5th gear is useable on flat ground but has lost just a tad of its power with it floored.



So if the car is down on power like this, does that mean I should turn the fuel screw in 1/8 a turn, readjust idle and see what happens?  I was kind of amazed already at the difference those lda changes made last time as it was a dog.

I haven't had issues with bubbles when running now but I noticed that I always have a single big bubble when the car has sat all night at the ip inlet.  And fuel has no prime behind the filter to the tank.  Doesn't seem to be an issue from what I can tell idling or reving it out.  Since I ran new lines and all of that stuff I would have to assume its an issue with the ip but there isn't a hint of a leak right now.  When I had the pump off to retime my mainshaft bushings are still tight and the seal was new just months ago, doesn't appear to be tweaked.
1985 turbo diesel jetta