cLAYH

Ok I have a '92 W250 CTD with OD tranny. I have followed the VE pump turning up directions on this site, full load screw in about 1 3/4 turns, tapered shaft 90* and star wheel 1/4 turn.

I intially started with the smoke screw down two turns but found that I had a lot of smoke on hard acceleration takeoffs prior to turbo spool up. I backed it off a 1/4 turn, the acceleration seemed to drop but the smoked just stayed the same. Is this smoke just something I will have to live with? I have no smoke anywhere else. The smoke I have at takeoff is enough to leave a pedestrian on the corner wheezing.

Also I'm having problems shifting into OD at WOT. In 3rd at WOT I will hit about 65-70MPh and 2700PRM and thats it. To continue acceleration I will have to back WAY off the throttle, speed will drop to 55MPH and then it will upshift. At which point if I put my foot back into it it will downshift again. I checked the TPS it was reading .35V at idle(engine off key on. I adjusted it to 1.2V at idle. It did not seem to make any difference. Any suggestions?

I also had to back the idle screw WAY off to get back to 750RPM is there a trick to this, that screw is a major @#$@#$!

Thanks for any tips you can offer this newbie!

Monty

Welcome to the DTR!

First off, you really need a set of gauges (pyro and boost psi) before you get real wild. Try backing your smoke screw all the way flush with the bottom of the pump housing. After this adjustment is made, you may want to turn your starwheel in a little more.

I never use the smoke screw, as it puts a preload on the diapraghm, which in turn pushes the eccentric down and starts the fuel pin at a deeper setting.

The idle screw is a pain. I have had good luck with a 10mm gear wrench or just a plain ole chisle and hammer. Just tap the nut with the chisle until it becomes loose. Then after you set it. tap it back tight with the chisle and hammer.

cLAYH

I already have a pyro gauge its after teh turbo. On a long hard hill pulling 6000# it would hit 950* max. Have not put a load on it since tampering with the pump. Still have to get a boost gauge.

I did the chisele and hammer thing on the idle screw, it was actually turning the thing that was a pain. Tried 4 different lengths of screw drivers, ended up using a set of needle nose pliers.

Any other opinions on the smoke screw? It does seem to increase the off line perfromance but there is a lot of smoke till the turbo catches up.

Alec

I am with Monty -- I have my smoke screw backed all of the way out. It just smokes mildly at full throttle with no boost -- then when the turbo spools up, more power and no smoke.

If you want faster take-offs without the smoke, you will have to change your turbine housing.

Good luck,

Alec

Redleg

I did the chisele and hammer thing on the idle screw, it was actually turning the thing that was a pain. Tried 4 different lengths of screw drivers, ended up using a set of needle nose pliers.
You might try a needle or wire and stick it in the hole at the end of the screw.

thumbs

Tell ya what I did with the idle screw. I used the chiesle trick to get it loose. Then I ran the nut all the way off the screw. I adjusted the idle and put the nut on the front of the screw where it stops the accelerator. I think it's an 11mm nut. I use an open end "tune up wrench" The little guys that come in a pack. To tighten and loosen the nut. I haven't found an easy way to adjust the screw but a long narrow screw driver.

I am about where you are on your adjustments and can't get rid of the smoke either. I have backed out three turns from stock and still get a lot of smoke. Power screw is in 1 1/2 turns from stock.

docwes

go to my post about WOT and there is a picture of how to get WOT, it takes all of 10 minutes and a two cent cotter pin

powerwagon440

ive got the same deal ill go to 70 mph and it wont shift back off and then it will shift. tps is bad or not set right? ill be searching for the WOT in 1st gens thanks!

hdm48

The TPS is stoping it from shifting into O/D. Back it off a little at a time until you get it where you want it. And if you turned up your high idle, you will need to do it again, along with your K/D cable.
Smoke screw,, I went so far as to machine out .060" in the top cap to reduce idle smoke when I ran the POD injectors. After going to the DD3+'s, I left it alone and I have very little lag if I stab it from an idle.
Idle adjust,, I use a set of pics. You know, the ones you use to pic out "O" rings and such.

Dave

powerwagon440

ok docwes ive looked and i cant find it i guess im not very good with the computer. if ya could point me in the right direction that would be great thanks!!!

Bushy

TPS ADJUSTMENT....

The TPS has a 3 wire connector on the top, engine side.
The center wire is orange (with blue stripe?) I believe.
Under the TPS body, is a shaft that protrudes downward. The shaft has a hex head end that fits into a 'female' hex socket.
This shaft is lightly spring loaded. When the hex headed bolt end is pulled upwards on removal the head/shaft may 'snap rotate' an 1/8 turn or so, so watch it as it comes out since it needs to go back in the same position.( Removal of the TPS happens when you want to access the inside of the AFC housing to adjust the diaphram or starwheel.) Just be sure to take a preliminary reading off the TPS before you remove it if that is part of the job your doing. (Like when taking the top off the injection pump)
Right near the top of the shaft were it first comes out of the TPS body, are two "flats" were you put your open end wrench to adjust.

You'll need a DC Voltmeter, as safety pin, or paperclip with the end slightly sharpened, and a combo wrench. I think its a 10mm.
Slip the safety pin or paperclip into the 'socket' part were the center wire comes out of until it makes connection with the metal jacket inside.
Connect the "+" probe of your DCVM to this.
Connect the "-" probe of your voltmeter to the "-" terminal on the battery (it's just convenient)
Turn on the Ign. key (do not start truck) and check the "at rest voltage".
It should range between .6 VDC and 1.20 VDC. (make a note of the reading for reference.)
Next, slowly cycle the throttle smoothly to WOT then back to "at rest" and watch the meter.
It (the needle) should increase smoothly up and down with no jumps or spasms/twitching.
If it does, the TPS is still working ok, if not you've got a dirty one or its failing.
I believe the total increase (above "at rest voltage&quot should be about 2.75 VDC.

Now, you need to go back to that shaft coming out from under the TPS.
Use the wrench to adjust the voltage SLIGHTLY!
Start with + .2 VDC to begin with (to delay 3-4 shift a bit) OR -.20vdc (to have 3-4 happen earlier.)
Increasing voltage will cause the 3-4 shift to happen LATER.
Decreasing voltage causes the shift to happen sooner.

I found that there was a point were the shift happened later, but also tended to cause the downshift (4-3) to be a bit touchy too, so you need to adjust a BIT and drive each time.
When you do your test drive try to use the same throttle pressure/RPM for each, that way you'll know what effect you had with the adjustment. I did a "medium" throttle (1600 RPM) and a WOT test each time.
Before I had the tranny work done mine ran just fine at about .7 VDC ~ .8 VDC "at rest".
Last thing to ckeck... make sure that your TV cable returns properly. The lever on the trans. case should move all the way forward with the truck off/idle. I had to add a "universal" throttle spring to be sure that happened, otherwise the line pressure(s) at idle are already increased above what they are supposed to be at idle and you may have harsh engagement when shifting from "P" or "N" into "D" or "R".
In the event you need to remove the top TPS body itself remove the two screws holding it down. Carefully lift it up and note that underneath there is a plastic slot and key type indexing. Once the TPS body is off you can turn it over and spray electrical contact cleaner into it, working it back and forth. The use some gentle compressed air to dry out the spray cleaner (it evaporates pretty quickly). Once done, re-install it and try the re-set procedure again and watch your dcv meter for smooth movement.
You can find some good pics of this thing in my 'Readers Rigs" gallery under VE Gallery label.
Hope this helps you if you need to work on the dreaded TPS.

Bob. aka: BushWakr

docwes

ok guys I think I got it to post, here is a pic of how to hold the TPS at 1.2 volts, don't try and mount the TPS back in its original location. I just tape it up and let it lay on top of the engine. It will elimnate eratic shifts and allow for full throttle 3/4 shifts. If you are pulling a trlr you may want to use the overdrive button to hold 3rd gear a little longer. You will think you are driving a whole different truck. good luck

cLAYH

Well yesterday I set my TPS according to the factory manual at 1.0V and could not get a 3-4 upsift unless I backed WAY out of the throttle nad sometimes still could not get one when pulling a hill. After reading Bushy's post(thanks Bushy) I backed it off to .7V and I still have to back off the throttle a fair bit but atleast it does it consistently now. Will try going down to .3V and see what happens. BTW is it bad to go too low? Also I noticed that it increases more than 2.75V at WOT, closer to 3.0V, is this indicative of a faulty TPS?

Bushy

Well according to the "Manual" it says the increase should range between 2.25 and 2.75 volts over the at rest reading.... but hey, that's the "manual".... I sit on mine to reach the pedals..... ;D

You can run that setting down further if you like. I have never had to go that low personally but others have and it seems to be ok.
You want that shift to happen well before you hit the defuel point, NOT THE GOVERNED POINT, the defuel point.
Stock trucks/pumps defuel at about 2450 and will govern out at about 2600 - 2650'ish.
Slip the ole girl into 2nd, and from a start go WOT.... watch/feel were you start to notice the trucks' pull fall away.
That is the defuel point. You're aiming to have your shifts (all of them) happen in advance of that point.
On mine for example (mine is a bit high still) I reach about 70-75 mph when it goes into OD at WOT.... man that sucker just honks boost and pulls like a demented missourri mule. (ok I can't spell it but you get the point )
It should be lower than that and I'm doing some dyno tweaking currently.

Does that help at all.... Oh here's a pic of the Breakover spring setting that changes when you mess with idle/governor/full fuel.

cLAYH

Thanks Bushy I'll tinker with it some more tonight.

Docews, had a look at your pic. May go to that as a last resort but for now I'm content to tinker with it. The TPS was put on for a reason and I'd like to understand it better before removing it.