TDC Offset -2.46?

[Billman]

Finally got the chance to time the pump after Gear Drive & Girdle install.

Timing didn't move from -1.76 where it was set. Pump was put back approx ~1mm to driver's side after gear install. But thinking -1.94 was better, and the fact that it seemed quieter, I attempted to time it.

Immediately jumped to -2.46 and is steady. Timing will not variate from there. Turned SES light on too.

I will have to wait until I get home to move pump back to original position, if not further.

What is the downside to -2.46?

[rjschoolcraft]

You're way past what the computer can actually compensate for. You should bump the pump toward the passenger side and do TDC Offset Learn again. If the number still holds steady, back off more. When the TDC offset numbers begin to cycle to different values, you're into a region that the computer can handle. Then wait for the offset you want and stop. You may still have to bump the pump slightly if you cannot get the number you want.

[Kennedy]

Nudge it back just a hair and redo the learn. Sometimes a shade more RPM will drop the value back,but if you go too high it will kick you out. 1100rpm fast idle seems to work.Once you've backed down from the -2.46 peg, try multiple learn sessions without moving the pump and see if your number comes up...

[Billman]

PO216 comes up. That's what I thought - the computer can't compensate that much.

I will bump it back to pass side to drop value. I never saw it steady where it didn't move at all.

JK - I thought I remeber you saying a little RPM during the learn will Increase the value. But I will try it to lower it temporarily.

I need to make it 50 miles to home before I can spend any real time on it.

Thanks Guys...

[TCombs]

If I understand this right,the higher number base timing,(approx.5-8*) the more neg.(-1.94). And the lower number(approx.3.5-4.0*) the less neg. (-.25 -.75) TDC values. ???

[Billman]

Moved the pump last night towards Pass. side ~1mm. I was afraid I went too far. I decided to leave it anyway.

Hooked Tech II and began process.

TDC Offset showed 0.00 before I did any Re-Learn??

First attempt and immediately went to -1.94. That was my target, but not being happy with hitting it right-off-the-bat, I tried again. At idle, and here's the weird part, less than 170*, it jumped to -2.46. The same value I originally got after the Gears went in.

Taking your advice JK, which I thought was backwards, was the only way to bring it down. After completely warmed up, Idle RPM would consistently produce -2.46. Off-idle was not as consistant but definately brought it down. The best I could do was -2.02. That's where it sits. Until I move the pump further, it will stay there because it won't set the MIL.

This is now leading me to believe that the Tech II wouldn't show a greater negative number than -2.46. With the pump 1mm towards the Drivers side, it was Steady -2.46.

On Edit: I just re-read your post and you already identified it as a -2.46 Peg...

[rjschoolcraft]

You should probably move the pump back further. Also, make sure you're completely warmed up before doing the learn.

When I put my engine back together, I set the pump in exactly the same position relative to the front cover as it was before. I had to move the pump back more than two mm to get the offset where I wanted it. JK told me that the reluctor wheel on the gearset is advanced compared to the factory crank sprocket.

[Billman]

I didn't really think of that, you're right.

The advance built into the new reluctor wheel is clearly visible...