98.5 in need of help

[Hammer]

Ok Gang,,I need a hand helping a friend and his 98. 5 and its slow to go power problem,,I have done a search and have my eyes crossed from looking at all the possible solutions,but,would like to rehash this once more for him(and me,got a wager on it),,His truck is a 98. 5 Quad 24 valver 2wd auto with a TST PM3-RV injectors-Bill K trans parts equipped ,so its got the proper parts for a beginning,,Here's where it gets murky to me,with all this the truck will not make any low end power(up to 1800 rpm)but from 1800 up it will fly and pull the house down,,He seems to think its a turbo related problem(system was pressure checked for leaks and none were found) but I think its fuel related(or lacking due to weak lift pump),,I will be checking the pressure on Monday early as he has never checked to pressure since the truck was new to him,,This is one of the trucks with the electric lift pump and not mechanical,,He does pull a 37' Gold Rush 5ver that hauls his Hemi SS/AA car and wants the low end to get her moving,,It has had all new IAT and Map sensors installed already and has the new TST harness on the PM3,,Could there be anything I am missing,any help is appreciated??,,Thanks... . Andy

 

[LSMITH]

Hammer, a big part of the "problem" is just that the DTT convertor is that tight. Put a stock TC in it and he will have a tire smoking beast that will not pull unless it is in lockup. There are compromises that have to be met to an extent. Have him call Bill at DTT and see if he has any suggestions for getting the power up a tad sooner. He if anyone would know. MHO, hope it helps.

 

[Roger rodbolt]

Bring it to Muncie!

Hammer,

Have your friend bring his truck (and you) to Muncie on June 8th and Chip from Blue Chip Diesel Performance will put a custom programmed timing box that will really perform at low rpms. There will be no obligation to buy the box but I'm betting that your friend will leave with a timing box and a smile .

 

[MCummings]

Hate to tell you this but my '98. 5 did the sae thing, but I never BOMBed it.



I had near Zero Power till 1800. Turned out after putting up with the Dog I put gauges,, My Lift pump was bad,, then about 1 month later with the truck still being a Dog it started missing, turned out to be a bad injection pump. I got it replaced under warrenty, only mods were Straight pipe and gauges.



Since he has no idea abut fuel pressure and has turned up the power the Injection may not be working to good on the low end. That's the way mine went out.



A new injection really Livened up the low-end and at Idle power.



You could also check EGT and Boost pressure. Does the surge of power come when boost starts rising? Then you are experiancing turbo lag, but once boost builds and the motor falls below 1,800 RPM the Power should still be strong.



Does the 1,800 RPM Lag thing only happen in 1st gear then go away?? Then it's most likely lag,, Cause by a tight Torque Converter, or a Turbo with a Big Housing.



an HX-35 turbo will spool hard at 1,500 RPM with Fuel (sounds like you have fuel) I personally can build 20-25 pounds of boost with my '35 at 1,600 RPM (Lots of smoke before it spools up though )



My thoughts are, a weak injection pump or Turbo Lag.

Which Torque Converter does he Have ?

Which Turbo?



He needs to know his Boost pressure, Exhaust Gas Temperature, and Fuel Pressure.



Gives us an update post.



Later,

Merrick Cummings Jr



P. S. I am by no means labeled a mechanic, but this is what I THINK Might be wrong.



I'm an expert at telling other people how to fix problems I don't have,, and about things I don't know. (In Good Humour)



I was tired when I wrote this, so if this post makes no sense,, is redundant,, or makes your head hurt. I'll try to explain anything yall might not understand when I am more "awake"

 

[Steve St.Laurent]

I can almost guarantee that he has a bad lift pump, but I agree with the above statement that it's probably the tight TC. TST can reprogram his PM3 with a program that puts in a lot of fuel down low that would help with that. Have him call TST and talk to Mark and find out what it would cost to reprogram it - I'm pretty sure it's cheap. Both Briar Hopper and myself are running custom TST boxes with the program that dumps fuel in down low - in our cases we're doing it to spool the turbo faster with manuals.

 

[JR2]

Fix his bad lift pump and then get a timing box installed. I personally thing the Edge EZ is a good choice.



JR2

 

[Hammer]

The convertor in the truck right now is the stock one as he thought the same as most here and figured it was too tight,,It makes little or no power down low and after driving it it will not even break the tires loose from a dead stop,,He is one who does not run any guages right now but has already decided that he is need of them(gotta love these old school guys),,The fuel pressures will be checked and I'll let you know what we find so far,,I myself not, even knowing much on these motors, kinda figure it will be a fuel or lack of fuel problem,,Oh well,its off I go to the shop and I'll need a big stick to drive my point home so to those who responded, thanks for the ideas,I'll post a updated later in the day... ... ... Andy