Help

[Ajdooley]

1994 gmc 6.5 turbo diesel...... Anyone that can help me locate all the grounds...... It runs fine just don't have power when it comes to climbing hills...... Have to let off fuel pedal for it to shift and rpms won't go over 2.5.......any help would be appreciate

 

[svein]

Have You checked your lift pump?

 

[JayTheCPA]

I am leaning toward either fuel or air starvation. What color is the exhaust when this happens?

Toward grounding locations, there is a good pictorial in the Tech section.

 

[Ajdooley]

Lift pump changed....... Just white smoke

 

[svein]

Have you checked that you get fuel all the way to the IP? When was your fuel filter last changed?

 

[Will L.]

Clear return line from ip- any bubbles?
White smoke smell like diesel or coolant?
What is fuel pressure (measured at the ip) at time when power loss occurs?
What boost when power loss occurs?

 

[Ajdooley]

Clear return line from ip- any bubbles?
White smoke smell like diesel or coolant?
What is fuel pressure (measured at the ip) at time when power loss occurs?
What boost when power loss occurs?

It smells like diesel......... Don't know rest bc no gages for that

 

[Ajdooley]

Have you checked that you get fuel all the way to the IP? When was your fuel filter last changed?

About a month or two when this started I let the truck sit for about two week bc of issues but had to start driving again for about two days it does ok then it gets bad again

 

[MrMarty51]

Grounds are located on the right rear of the intake manifold.
I got a cheap Hurst fuel pressure gauge, mounted it with a bent piece of steel plumbers tape {the stuff with holes evenly spaced and about 3/4" wide or so } and used a convenient screw under the left side of dash for mounting it.

 

[JayTheCPA]

From the PM, it seems like the question is where to find the Tech Library:

6.2 and 6.5 Technical Reference Library

Guides, Part lists, How-To-DIY, and other Technical information for the 6.2 and 6.5 Series

www.thetruckstop.us

Lots of good information in there


From the additional description of white smoke smelling like fuel, perhaps the timing has gone retarded or there is a significant pressure leak which is preventing the fuel from flashing.

 

[JMJNet]

On a 94, the OPS runs the Lift Pump.
So if you replace LP but the OPS is still bad (can be intermittent on the way out), then you are only solving half of the problem.
Not saying that this is the only problem.

Use only ACDelco OPS D1808A, no aftermarket.
On the LP, use the LP from 93 model year EP158 or equivalent.