Yet Another Timing Question

[Journeydog]

The manual says that after installing an IP, one should align the factory timing marks as a starting point. Then, move the pump - slightly - one way or the other to achieve the desired timing. All the while, using a TechTool to set the base timing and TDP offset. Got that...but my question is, how far off from the factory marks do you usually rotate the pump? i.e., how far away from the marks do you usually end up? My engine is new with a new IP and has been adjusted first by a bird brain with no TT and then by a GM shop. Both times, the result ended up with the pump mark setting about 1/4" to the driver's side of the block mark. I checked the timing with a TT2 and it floats around 3.5 deg. (9.5 actual-9.5 measured) and -0.26 TDC offset, so that's in the good ballpark. I'm just thrown off by what seems to be a big delta between the factory marks and actual setting and I can't see how the thing would run with the factory marks aligned. Is everything okey dokey here, or is something screwy?

[gmctd]

The TDC tool is attached to the timing cover, so mark on all timing covers should be very close.

Inj pump is the variable, so pump marks will seldom align from timing cover to timing cover.

Set timing with Tech II, then scribe new mark on inj pump for future reference.

[Journeydog]

Just seems like that is a very large variable, given that the difference in the widths of scribe marks make for major timing changes. Everything I see in the manuals shows a close relationship in terms of the physical location between the static timing marks. This one is like hundreds of scribe marks different. The procedure for installing a new pump states that one should start by aligning the static marks and then taking it from there with a TechTool. I very much doubt that the engine would even start with my setup and I'm just wondering why there is such a discrepancy in the location of the marks.

[gmctd]

I'm gonna try some numbers here, so have your salt on the ready -

1mm is about 2deg, where 1/4" = ~7mm = ~14deg

So, we can come to only one inescapable conclusion - your engine just simply does not run! ;)

Or - that inj pump was not statically timed and marked on your engine.

I have six handfulls of DS-4's, including the 5088 off my engine and one new out-of-the-box, for a grand total of six.
That's two 5088's and four 5122's.

None of which has any static timing mark(s) installed.

Meaning - if your engine timing TECHs out ok, simply scribe a line adjacent to the mark on the timing cover for future base-line reference with that inj pump.

Far as that "other" mark - tell the Diesel technician "Don't go there! That line is NOT your friend". ;)
:cool: