O.T. Calling jdemaris for 6.5 diesel questions

I just had the injection pump changed out by a local shop here in the FL panhandle. Engine runs good with no more codes. Wastegate solenoid & oil pressure sending unit also changed. Here's the situation: The engine has to spin over for about 3-5 seconds before it will start. I believe the timing is retarded somewhat, causing the slow "light-off". For the life of this vehicle ('95 C2500 Suburban) and with multiple injection pumps replaced under warranty, the engine has always fired up on the first compression cylinder while cranking. Now it almost seems to not want to start. Even when we brought the vehicle in for the work (on a roll-back truck) I cranked it up to drive it off the truck and it started on the first instant of cranking. Before the repair, the engine would shut down intermittently while driving and we had exhausted all the usual culprits (air in system, lift pump, PMD, filter etc.) as to why. I've already called the shop and the assistant manager said he could reset the timing. (He also agreed that the timing error would cause the problem with slow starting.) So my first question is do you agreed with the timing issue or could it be something else? 2nd question--will they have to remove the pump to reset the timing or can this be done through the PMD? I plan to bring the vehicle back on Monday to get it checked out and I expect the shop owner will resist doing the job over. Thanks in advance for your help.

Timing could be the culprit,takes loosening the 3 mounting bolts and turning pump wee bit to dr side to advance timing.Relearn of computer is needed too depending on what model pump you have.
I never done that yet.Need tech ll scanner for that.

Thanks bison,

I knew this could be done on my Perkins 6-354 & Ford 172 but wasn't sure about the 6.5. Won't the fuel lines have to be "bent" a little to allow the pump to rotate for the timing adjustment?

Hi Kevin,

If it's anything like my VW diesel, a 1/32" movement was huge in timing. That would also effect my fuel mileage, 48mpg being slightly off the mark vs 52mpg when at it's best.

On any puter controlled engine, total default reset is accomplished with disconnecting the battery(s) for a couple hours. Om my 7.3 PSD they use a KAM (keep alive memory) chip and it takes time to bleed of the caps to reset to the defaults. I like over night.

Using this method on every 5k oil change, keeps my fuel mileage higher and slightly better preformance than not resetting my puter.

T_Bone

no need to bend lines.pump ofset is 1 to 2 mm max. go to www.dieselplace.com to find anything related to the 6.5 GM diesel

You say the thing was randomly shutting off on you? On the 6.5 thats a sigh of the PMD going bad. Its the little control that plugs into the harness that runs the pump. Might want to look into that.

With the new pump also came a new remote mounted PMD with heat sink. As to the PMD on the old pump, the local Chevy dealer had the vehicle for three weeks trying to diagnose the problem and their final ruling was that the pump was bad. They never said anything about the PMD. I tend to agree with you though, since the engine would restart after a 3-4 hour cool-down. Problem is it would only run for about 3 miles and then shut down again.