2nd Gen Non-Engine/Transmission Low boost (I think)

[hilda]

Just finished installing the finial 2 gauges Boost & FP. Good new is fuel pressure is 12lbs idle and 10 @ 65, bad news boost is low @ 65 is was 5lbs. If I down shifted, run it up to about 2400rpm it reached 20 just for a split second then dropped real fast. It does not seem to make any boost under 2000rpm. I have alway felt this truck had high EGT, I can get the EGT to 1000 under acceleration just getting on the FWY not towing.



Now I live at 7000 ft, but should the boost be this low.



Thanks in advance



Jim

 

[tazzen]

the only time you have boost is under load. i can do 70 on the flats with only 5 lbs of boost. going up hill i can hit 30 lbs of boost hammer the pedal down.



ed

 

[OL RATLR]

Just finished installing the finial 2 gauges Boost & FP. Good new is fuel pressure is 12lbs idle and 10 @ 65, bad news boost is low @ 65 is was 5lbs. If I down shifted, run it up to about 2400rpm it reached 20 just for a split second then dropped real fast. It does not seem to make any boost under 2000rpm. I have alway felt this truck had high EGT, I can get the EGT to 1000 under acceleration just getting on the FWY not towing.



Now I live at 7000 ft, but should the boost be this low.



Thanks in advance



Jim

Sounds about right.

 

[Missouri Mule]

12 psi, seems like your lift pump is starting its journey of going out. Pressure at idle should be 14 to 16 psi.

Rev your enigne in park and see where the pressure is. The pressure should go up quite a bit with no load on engine.



Your truck should make boost right from the start. But 5 psi is ok running on a flat highway without a load. I would still check out turbo system for leaks. IIRC your wastegate opens up in the 20 psi or higher (not higher that 25 psi).

 

[hilda]

12 psi, seems like your lift pump is starting its journey of going out. Pressure at idle should be 14 to 16 psi.

Rev your enigne in park and see where the pressure is. The pressure should go up quite a bit with no load on engine.



Your truck should make boost right from the start. But 5 psi is ok running on a flat highway without a load. I would still check out turbo system for leaks. IIRC your wastegate opens up in the 20 psi or higher (not higher that 25 psi).

I spent last night working on the turbo system, I don't believe it's ever been apart all of the clamp bolts were gummed up I had to use vise grips on the shafts to free up the nuts. Took everything apart looking for holes tears etc, Did not see anything wrong, but that does not mean anything can't see air leak.



I need more boost, the way this is now, by the time I get boost the EGT are 1100+. This truck has never pulled well. My old bone stock 98. 5 pulled better.



I'll keep an eye on the FP