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Engine Specific Info and Questions => IDI Engine => Topic started by: MontanaGTD on August 02, 2007, 02:10:49 pm

Title: Why cant I adjust my fuel screw?
Post by: MontanaGTD on August 02, 2007, 02:10:49 pm
I've had a go at it twice with come penetrating oil to loosen it off, but no matter how I try - or which kind of screwdriver I try I cant get it to budge!

Here are a couple of pics of my fuel pump/screw:-

(http://i17.photobucket.com/albums/b58/mrdubstyle/Image053-1.jpg)
(http://i17.photobucket.com/albums/b58/mrdubstyle/Image054.jpg)

Any help would be great!
Title: Why cant I adjust my fuel screw?
Post by: coke on August 02, 2007, 02:14:42 pm
There is a 13mm nut behind it that has to be loosened first, did you do that?
Title: Why cant I adjust my fuel screw?
Post by: MontanaGTD on August 02, 2007, 03:16:01 pm
Mine has a loose plastic collar, but no 13mm nut! Unless I have to break off that loose plastic collar?
Title: Why cant I adjust my fuel screw?
Post by: BruceM31 on August 02, 2007, 03:26:32 pm
you have to remove the lock collar that is stpot welded to the screw itself.  with that collar on you can back it off but not turn it in.  easiest way to do it is remove the screw completely and cut the collar off.  then you should be good to go!
Title: Why cant I adjust my fuel screw?
Post by: MontanaGTD on August 02, 2007, 03:47:25 pm
I cant move the screw let alone remove it!
Title: Why cant I adjust my fuel screw?
Post by: jtanguay on August 02, 2007, 07:36:09 pm
you need to break that piece off.  its a safety thing so that you can't adjust your fueling....
Title: Why cant I adjust my fuel screw?
Post by: RabbitJockey on August 02, 2007, 08:28:51 pm
yeah its a little piece of metal, just figure out where the ends of it are, and then pry it apart and pull it off, its madd easy,
Title: Why cant I adjust my fuel screw?
Post by: saurkraut on August 03, 2007, 06:12:46 am
That black plastic collar needs to be removed.  The 13mm jam nut resides under it.  You may have all the adjustability you want with out removeing the steel collar.  My steel collar is on, and I'm getting enough fuel off the LDA cone to push over 20 PSI boost easily.
Title: Why cant I adjust my fuel screw?
Post by: compu_85 on August 03, 2007, 07:29:24 am
Hmm, so if you remove the steel collar, you can adjust it in more?

-Jason
Title: Why cant I adjust my fuel screw?
Post by: saurkraut on August 03, 2007, 08:27:25 am
Yup.

But if you have a TD pump, try rotating your boost pin to the steepest slope and try that first.  The results are pritty darn dramatic, and it doesn't fork up your idle, our your return to idle.
Title: Why cant I adjust my fuel screw?
Post by: con on August 03, 2007, 08:51:14 am
I'm about to increase my fuel too. Has anyone got their boost set at 1.2 bar? If so how many turns of the fuel screw would be ideal to suit this boost level? My car is a 1.6 GTD and has an intercooler.
Title: Why cant I adjust my fuel screw?
Post by: saurkraut on August 03, 2007, 11:29:16 am
I'm a little above 1.6 bar.  The collar is still on my fuel screw, and its not turned more that 1/8th turn.

Turning the fuel screw will not significantly change your boost.  if your waste gate still opens at 1 bar, thats pritty much all you'll get, unless you really go nutz on the fuel screw and get boost creep.  Then you'll get alot of smoke, hi EGT, and more power.

If you have a KKK turbo, you can turn in the screw on the waste gate and raise your boost a little.  If you turn the screw in alot, the waste gate won't open all the way, and you'll have sort of a earlier boost creep, with less bypass, which gives lower EGTs than full boost creep.  This is essentially what I have now.

The right way is a 'boost controller' (valve) to change the waste gate opening point.   This way you can hit your boost target with out touching the fuel screw, and then adjusting your LDA pin to achieve the desired smoke/power level.

Anybody figure out where to get screw in hoze barbs for the KKK turbos?
Title: Why cant I adjust my fuel screw?
Post by: MontanaGTD on August 03, 2007, 12:42:49 pm
Already done the fuel pin rotation and i'm running at 0.5bar at the moment - got a custom filter in the std air box with the restrictor removed and a mufflerectomy on the backbox - but other than that its std - I did 110mph out of it this evening on the way home without trying!
Title: Why cant I adjust my fuel screw?
Post by: compu_85 on August 03, 2007, 12:47:29 pm
Sadly I just have an NA pump on the car right now. But I'll try that lill trick :)

No bits will fall out of the pump when the screw is removed, right?

-Jason
Title: Why cant I adjust my fuel screw?
Post by: saurkraut on August 03, 2007, 12:52:15 pm
"i'm running at 0.5bar at the moment"

If you have your boost pin maxed out and you only get .5 bar, you have to do somehing about your waste gate.

More fuel with no more boost is an EGT problem waiting to happen.

Its kind of a chicken/egg thing: the more booste you get, the more pin move ment you get, the more fuel you get, the more boost you get....
Title: Why cant I adjust my fuel screw?
Post by: MontanaGTD on August 03, 2007, 01:35:13 pm
I dont have one of them adjustable arms with the 2 lock nuts on it for the wastegate - I know how to diable the BOV - how do i adjust the wastegate then?
Title: boost
Post by: bigblockchev on August 03, 2007, 08:28:50 pm
Do you have a setscrew with a locknut on the back of the wastegate If so you can loosen the 10mm locknut and screw the setscrew clockwise (in) to give more preload on the wastegate spring this will allow the wastegate to build up more pressure before opening. Voila more boost don't go nuts though try a bit at a time. Cheers Dan
Title: Why cant I adjust my fuel screw?
Post by: jtanguay on August 03, 2007, 09:12:43 pm
Quote from: "compu_85"
Sadly I just have an NA pump on the car right now. But I'll try that lill trick :)

No bits will fall out of the pump when the screw is removed, right?

-Jason


remove the fuel screw? I would leave it in.  always measure each 1/4 or 1/8 of a turn you do so that you can bring it back to normal again.  breaking the collar off is pretty easy.  something pointy and a mallet or hammer should do it.
Title: Why cant I adjust my fuel screw?
Post by: hillfolk'r on August 03, 2007, 10:12:25 pm
the more you run the fuelscrew in,the more you have to bring the idle back down
do this:
 start the engine+blip the throttle from under the hood,like to 3500 rpms or so
note how fast the revs drop
shut it off
then turn in the fuel screw a little(like 1/4 turn)
start it up,does the idle sound higher?it is usually only a little,barely noticible,like 50-100 rpms
if so turn down the idle a little
if  it still sounds like its idling high  be careful because if you blip the throttle as the revs drop,they may not drop,or it may run away!!! so yank the fuel solenoid wire very quickly if it does
if the idle isnt low enough,you will notice the revs will "hang" in between gear changes on a road test
its a give/take thing....
run in the fuel screw,you have to back the idle off
you will notice if the idle is too high,because if you road test it and rev out (lets say) 3rd gear to max rpm,and let off the throttle in gear,and it stays in"cruise control mode",,then turn down the idle
Title: Why cant I adjust my fuel screw?
Post by: nokivasara on August 04, 2007, 07:31:26 am
Quote from: "hillfolk'r"
the more you run the fuelscrew in,the more you have to bring the idle back down
do this:
 start the engine+blip the throttle from under the hood,like to 3500 rpms or so
note how fast the revs drop
shut it off


I usually adjust the fueling with the engine running...
Title: Why cant I adjust my fuel screw?
Post by: MontanaGTD on August 05, 2007, 12:39:23 am
Can someone show me where the setscrew on the wastegate is so i can adjust it a little?

I have loads of work to do on the car today - thermostat is jammed - rad fan is seized. This just happened yesterday! Annoyed!
Title: Why cant I adjust my fuel screw?
Post by: saurkraut on August 05, 2007, 06:42:30 am
Do you have a KKK or Garrett turbo?  If its a Garrett, I think your only option is to do the boost controller thing (pressure regulator) in the waste gaite line.

If its a KKK, you may be able to get at it from the under the car, behind the engine.  The waste gate can is a stainless steel cylinder, paralell to the turbo.  The end of it should have an allen screw and a 10mm jam nut.  Back off and hold the jam nut, turn in the allan screw in at leaste a couple of full turns.  your first adjustment my yield little change.  Boost is raised by turning the screw in enough to limite the amount that the waste gate can open.  It will take a few adjustments to get significant results.

This works, and although I'm using it right now on my car, its a band aid approach.  The right way is the pressure regulator route.  But the fittings are metric, and its probably going to be tiough finding small metric hoze barbs around here.
Title: Why cant I adjust my fuel screw?
Post by: MontanaGTD on August 05, 2007, 10:50:39 am
Ok more problems!

Can i have a bit of advice Please?

My thermostat has been a bit sticky and my rad fan switch has been on the blink.

So ordered a new thermostat and seal, and a new rad switch. but in the mean time i rigged a switch on the dash to turn the rad fan on when it starts to get hot.

Now the rad fan has seized solid!

So started this afternoon in the poring rain by removing the thermostat and draining the system. Refit the thermostat cover and ran some rad flush through it. Drained it again refit the new thermostat and seal. Then refilled it with some water and anti-freeze - let it run for a while with the heater on full and the cap off the expansion bottle and filled it up - took just over 5 litres. But on taking it out for a test drive the temp guage went very high and the interior felt like a sauna!

Now I only have a fan which works when it wants to on the switch on the dash - but surely the car should run cool enough to get me to a mates place (about 30 miles away) to get him to check it?

I'm going upto his to collect a new fan and see if that makes a difference!
Anyone had similar problems? It never use to above the mark which is half way - now its at the 2nd highest white line!!!
Title: hose barb fittings
Post by: bigblockchev on August 05, 2007, 02:11:16 pm
Sauerkraut  I have found that 1/8' pipe thread fittings will seal up nicely in the threads of the turbo housing. A bit of teflon tape helps too. Doesn't seem to screw up the threads either as you can screw the original fitting back in easily. I think the threads might be BSP or british straight pipe which has the same pitch as normal pipe thread but is not tapered. Cheers Dan
Title: Why cant I adjust my fuel screw?
Post by: saurkraut on August 05, 2007, 05:32:39 pm
Thanks!
Title: Why cant I adjust my fuel screw?
Post by: HP on August 07, 2007, 03:39:32 pm
Quote from: "hillfolk'r"
the more you run the fuelscrew in,the more you have to bring the idle back down
do this:
 start the engine+blip the throttle from under the hood,like to 3500 rpms or so
note how fast the revs drop
shut it off
then turn in the fuel screw a little(like 1/4 turn)
start it up,does the idle sound higher?it is usually only a little,barely noticible,like 50-100 rpms
if so turn down the idle a little
if  it still sounds like its idling high  be careful because if you blip the throttle as the revs drop,they may not drop,or it may run away!!! so yank the fuel solenoid wire very quickly if it does
if the idle isnt low enough,you will notice the revs will "hang" in between gear changes on a road test
its a give/take thing....
run in the fuel screw,you have to back the idle off
you will notice if the idle is too high,because if you road test it and rev out (lets say) 3rd gear to max rpm,and let off the throttle in gear,and it stays in"cruise control mode",,then turn down the idle

Just how do you turn down the idle :?:
Title: Why cant I adjust my fuel screw?
Post by: hillfolk'r on August 07, 2007, 08:42:48 pm
notice where the throttle lever sits at idle,,,??
back out the screw that the throttle lever sits against at rest to get a lower idle

Sauerkraut I have found that 1/8' pipe thread fittings will seal up nicely in the threads of the turbo housing. A bit of teflon tape helps too. Doesn't seem to screw up the threads either as you can screw the original fitting back in easily. I think the threads might be BSP or british straight pipe which has the same pitch as normal pipe thread but is not tapered. Cheers Dan


us 1/8 pipe thread is 1/8 -27 threads per inch
bsp 1/8 is 1/8 by 28 tpi
just a little different,and bsp is still tapered
itll work if you are careful,but if you have to disassemble/reassemble a few times it can start to mess up the threads
Title: Why cant I adjust my fuel screw?
Post by: bigblockchev on August 08, 2007, 08:20:11 pm
Hillfolk'r you are correct regarding the pitch of the thread for the turbocharger fitting. There is a difference of 1 tpi. My terminology was not correct, the thread I was referring to is a BSPP or British standard parallel pipe thread, not British straight pipe as stated. This is characterized by the sealing washer under the face of the head (which the turbo has) or o-ring. The BSPT or British standard pipe tapered uses a 1deg 47 sec taper on the threads to seal in a similar fashion to the NPTF threads mostly used in North America. See http://www.malonespecialtyinc.com/tech.htm#anchor133719
My apologies to anyone who was confused by the incorrect reference. Cheers Dan
Title: Why cant I adjust my fuel screw?
Post by: MontanaGTD on August 10, 2007, 03:21:38 pm
How can I find out what turbo I have??
Title: Why cant I adjust my fuel screw?
Post by: rubadubdub on August 10, 2007, 03:46:58 pm
Theres an ID tag on the side of the turbo where the air enters from the air filter box. Pull a few pipes off around this area and have a look what it says on the tag.

I'd be interested to find out what yours is. I checked mine the other day as im looking at rebuild kits and found it was a water cooled T2. Didnt even know GTDs had garrett T2s! Anyone know if they did or has mine been replaced in the past? (Apologies for hijacking the thread montanaGTD)
Title: Why cant I adjust my fuel screw?
Post by: MontanaGTD on August 10, 2007, 04:45:51 pm
I'm 90% sure its a Garrett