2006 6.0- No Sync, Cam Slipped?

Bruce Amacker · August 7, 2012

18 pulses left:

30 pulses left:

This is my known good, 14 pulses left:

New CMP, harness, no start, ICP between 900-2000 cranking.

It looks like the cam has slipped or is slipping. What would cause this?

:grin:

Jim Warman · August 7, 2012

I'm assuming that the top two pics are the same engine but different instances?

With the way the cam gear is pressed on to the shaft, I'd be a little skeptical about the cam slipping (but I haven't seen everything there is to see - back in the 70's I came across a Ford 240 CID with a broken cam that would run well sometimes and not start others). It would be easier for me to imagine a damaged or loose crank trigger wheel as a possibility.

The spacing of the pulses suggests the engine is cranking over evenly without significant variation in rpm but the amplitude shows what could be an interesting trend.

Brad Clayton · August 7, 2012

The cam signal falling that far behind the ckp signal sounds like the ckp trigger wheel is slipping badly on the crankshaft.

blackop555 · August 18, 2012

have to agree with mr clayton on this one.

KarlW · September 5, 2015

Hi Bruce & everyone

It looks to me (rookie)like there is a variance in the ckp trigger wheel =ing either speed or gap change (walking)

Hard to tell from a picture.

Did that ckp signal repeat like that in the image?

Was there a resolution to this one? Was the ckp trigger wheel hanging on by its last legs

Forgive me with so many questions

I know this post is old but was curious is all

Been reading a lot of you guys post and have been really enjoying them

Bruce Amacker · September 5, 2015

If there was a conclusion I would have posted it. To be honest, I don't remember, I think they put a short block in it.......

September 7, 2015

This engine was removed and rebuilt by the customer. After installation, it did not start.

RPM pid kept jumping from 0 to 150 and there was no sync.

Somewhere during the process, the crank sensor trigger wheel teeth were hit and flattened/damaged. It was visible with a boroscope through the crank sensor hole, but hard to see and could be missed. It is very easy to see on the scope, the amplitude drops off.