Engine/Transmission (1994 - 1998) No boost pressure

[RALLER]

Way down on power, boost guage stays on O. I changed fuel filter,checked pre filter scren, was clean. The intercooler & hoses look ok. If the waste gate was stuck open, would that cause no boost? Problem was first encountered on the way back from california, sometimes boost and sometimes no boost. this is a 97 3500. Where do i look next? I will appreciate any help. Thanks in advance. BOB Aller Las Vegas NV

 

[RALLER]

Turbo is not locked up, spins up with engin RPM. BOB ALLER

 

[55gene]

If you haven't upgraded your fuel lines they may be pulling in some air. Can you see any fuel leaks along the path of the lines underneath? Try cracking the bleeder nut on the fuel filter and then manualy work the lift pump to see if the LP is pushing out fuel there. Every rig will have some issues at some point in time. These old 12 valves are the most bullet-proof. Good luck.

55gene

 

[fest3er]

If you haven't upgraded your fuel lines they may be pulling in some air. Can you see any fuel leaks along the path of the lines underneath? Try cracking the bleeder nut on the fuel filter and then manualy work the lift pump to see if the LP is pushing out fuel there. Every rig will have some issues at some point in time. These old 12 valves are the most bullet-proof. Good luck.

55gene

Sucking wind I mean air into the fuel, a failing lift pump, and even the intake heater relays sticking on and melting the manifold-to-AFC line can all cause loss of boost and power. Do you even *smell* any fuel under the hood after driving it?

 

[SFPADGETT]

If the boost comes and goes, I would look at the waste gate sticking and / or loose hose clamps. When you have boost, what PSI do you have and how does that compare to normal? Are you getting alot black smoke out the tail pipe? (fuel but no air)

 

[RALLER]

Made up a fuel pressure guage (liquid filled). Fould pressure bouncing all over the guage at idle and with rs. Pinched off return line, got 60#. Have pressure relief valve coming from Genos. Thanks for the tips. BOB

 

[snappy]

SFPADGETT said it and said it well. Boost coming and going is a wastegate problem.

 

[LVJUNIOR]

raller did the boost test turn up any leaks? what was the fuel presure with the new gage setup?

 

[RALLER]

Found the problem

Exaust brake was partially on. BD brand. Selonide valve is bad. Have a new one on order. Wired exaust brake open, got the zoom back (30#) boost. Stretched the spring in fuel pressure valve, got 20#. Had no smoke before, now i get smoke on full exceleration. Genos new fuel pressure regulater was shiped today. Thanks ever body for the tips. I am recouperating from a heart attack , april first. Some days i dont feel good enough to walk the dog around the block. Iam geting better.

 

[hsmith]

Hang in there and get your strength back. Gonna take a while too.

All the best.