injector pump replacement

[Reid]

i'm replacing my injector pump on my 95' 6.5 turbo. is it necessary to set the timing and if so, why? thanks

[charliepeterson]

If you mark the old pump to the timing case and mark the new pump in the same spot and line up all the marks you should be ok.

If the dealer has been the only one to do this work you should change the timing. The dealer is very conservative with thiming numbers (-.25to-.50) TDC. If you bump the numbers to -1.50to-1.94 TDC the starts get better and performance increases as well. If you don't have a pyrometer in the exhaust pipe now is a good time to put one in. Extreme exhaust temps. will kill the engine.

Being a '95 how many miles on the Injectors? After 80,000 they really don't owe you anything.

[Reid]

well, i bought the truck with 130,000 miles on it. it now has 252,000 miles. i haven't changed the injectors, and i am just now changing the injector pump. it has no pyrometer. so the timing will automatically be off now after replacing the injector pump? i lined the new pump with the old one and put it on the way the old one was on there.

[charliepeterson]

The electronics in the Injection Pump have a "window" built into the program to compensate for timing chain wear. If you got the pump lined up in this "window" then you will be all set. If the pump wasn't lined up right then the truck might not start and an engine code will set for the timing difference.

With the high mileage I wouldn't go too crazy with changing timing numbers. Stay in the stock window of -.50 TDC.

[Reid]

yeah, i was trying to avoid the hassle of dealing with the timing entirely. i've apparently now got something loose or not hooked back up right last night, i went to crank it and got some sparks from under the hood? thanks for the help Charlie.