Setting boost,fuel, TPS etc.

[robscarab]

Hi all,

Im looking for some setup recomendations please?

I have been testing my new engine by towing a 9000 lb trailer and these are the results after 500 miles.

18:1 pistons, DB2 IP, GM8 turbo,new heads, recon crank uncut,599 block 4L80E rebuilt.

Initial settings:

Boost = 16psi max while towing up hill 15 psi max unloaded
EGT after turbo = 700F max while towing up hill
Lots of diesel knock at idle and cruise
Sloppy shifting @ too high rpm

Turned boost down, retarded the IP about 1/8 inch and set TPS at 1.5V at idle and 4.6 volt WOT.

Max Boost= 13psi towing, 11psi not towing
EGT 800 max, 350 while cruising no trailer, 400 cruising with trailer
Much less diesel knock but more than stock,(at idle and cruise)
Shift points are good but too soft for long clutch life in my opinion, no codes or slipping after the shift has occured.

The pump was set up with 1/8 turn above stock setting and I have not changed it yet.

I would like some recommendations as to:

whether I should increase the fuel another 1/8 turn?

lower or increase the boost?

Change the timing?

Move the TPS to provide a different volt reading ?

I am looking for max safe power and efficiantcy, minimum diesel knock, firmer shifts etc. It runs pretty good right now but I would like to improve upon what I have so far. By the way it starts great both hot and cold and engine temp remains at 190-210. The ambiant temp while testing is only about 60-70 degrees F.

Thanks very much,

[robscarab]

Really hoping to head out soon, but I'm a little nervous about my current set-up. The good diesel guys around here are booked for at least a week and I could use some of the vast experiance of TDP members! I am mainly concerned with the TPS setting since I cannot find a clear answer as to the correct setting. If at all possible I would like to increase the firmness of my shifts to prevent undo slippage during the shift. I am not sure if this can be improved by just setting the TPS diferently. I know the TPS has an affect on line pressure and therefore I am hoping that moving it one way or another will enhance the firmness while shifting.

I have other questions above but if someone can give me an answer to this TPS question I will feel confident enough to head out on my 4000 km trip with the kids.... Even if somebody knows the OEM stock baseline setting that would help greatly!

[gmctd]

When you turn up the IP to increase fuel, you'll need to reset the TPS to compensate - you get more fuel at earlier throttle angle, which is more power sooner, where you'll not push the go-pedal so hard, which requires advancing the TPS to improve trans line pressures

I'd go back up to 16psi on the Boost, since the EGT was lower at full load with that setting - 700 vs 800

You might check the return fuel line - any blockage messes with advance - also, push the mech advance lever in at the bottom, see how the internal hydraulic advance responds - then do a search for member Britannic for in-depth DB2 timing\advance setup

[robscarab]

Thanks very much GMCTD,

I found some great stuff by Britannic but after lots of searching still cannot find the in depth pump setup info. I have found some references to it and even a link, but the link does not work for me?

Which way do I turn the TPS to advance it? I am presuming clockwise? What Is the stock voltage reading ?

I purchased an expensive scan tool that has OBD1 capability as well as OBD2 but I still need a cable to connect to my ALDL style plug! When I get the cable I will be able to check line pressures at different TPS settings, but until I get the cable I am flying blind! I really have to depart tomorrow but I am concerned about frying my new tranny in the middle of nowhere...

Is it possible to set the TPS so that you actually feel a firmer shift? Will a side affect of advancing it be higher shift points? (or hopefully lower shift points)...

Thanks very much

[More Power]

This thread contains info on the TPS:

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=625

Rotate the TSP opposite to throttle shaft rotation to advance it (downshift sooner, firmer shifts, etc). :)

Jim

[Turbo Al]

Is it intercooled?? I found on my 1993 the max benifit from increased boost seemed to end right around the 12 to 13 lb mark. I have since bought an intercooler -- not installed yet.
Al