Having trouble with GM injection pump

• GM diesel

Thanks,

Allan

Those fly-by-wire pumps are a total nightmare!

If they are anything like they used to be, half of the problem lies in the tech's reprogramming the thing and half in his lucking out and getting a decent pump. I've seen 'em come 3 bad ones in a row (been that way since '94), so dunno what your guys are fightin'.

I don't miss that part of GM at all! Come to think of it, I don't miss any part of GM! :>)

What's the fight? Are they tryin' to tell you that you are providing the water/trash in the tank?

Allan

I have put 125,000 miles on the pickup since I've had it, without ANY pump trouble, so they're not all bad!

Have they checked the electric lift pump in the frame rail for proper operation, flow and pressure? Those pumps are known to fail, or have intermittant problems, or the oil pressure switch that turns them on can quit, or get intermittant, also. Problems here will cause all sorts of problems that get blamed on the injection pump.

A bad crankshaft postion sensor in the front engine cover, or even a worn timing chain, or bad crankshaft vibration dampner can cause the computer controlled pump to do all sorts of weird things.

In my area, generally the GM dealers apparently don't mess with the diesel fuel system, but rather, "farm it out" to the authorized Stanadyne shops. (They send the whole vehicle over there).

Maybe you could get this thing settled, even if you had to pay for the visit yourself, by going to an authorized Stanadyne dealer. Yes, these things have caused some problems, but I suspect someone is overlooking something on your truck.

What year is your pickup? From about 1988 until at least '96 or '97, the electric lift pump was in the LH frame rail, more or less under the driver. I'm not sure if they moved it to the tank AFTER that.

Have you been to: www.thedieselpage.com ?

There's a wealth of GM diesel info there, some free and some members only information. I've found it well worth the cost of a membership.