Timing questions

[Monopoly]

Worked some more on getting the correct timing set today. We thought it was right but then I noticed this week it didn't want to start, I thought it was either to fast or had advanced itself. Turns out the starter was bad.

Anyways, the timing mark on the dampner seems to have moved. We put a piston stop in and got close to finding the new TDC. Unplugged brown wire and set timing to 0. Plugged the wire back in and re-checked, timing now reads about 18 degrees advanced? Does anyone know if that sounds right?

Also, I need to find exact TDC. Going to pull shroud/fan and put a degree wheel on. Any other thoughts for this? Thanks guys.

Reggie

 

[Monopoly]

Re: Timing questions

More questions. Was just doing some reading about vacuum pressure. Sounds like it should be around 18 or so on a mostly stock truck? Mine is reading 12, that's at approx 900rpm while at idle. Truck has new vacuum lines.

Looks like another issue to work on.

 

[Monopoly]

Re: Timing questions

I think there is more going on than just the timing. Got home after family stuff today and pulled the plugs back out, they have less than 100 miles on them.

1&2: Half of the plugs are soaked, oil I think. Other half is dry

3&4: Are wet, same as above

5&6: Are bone dry

??

Right now I'm going to get the timing set 100% at 0 and see if I've got a vacuum leak that's causing the low pressure. If I don't have a leak I think it's finally time to get some data.

Thoughts?

 

[WyoSyclone]

Re: Timing questions

Worked some more on getting the correct timing set today. We thought it was right but then I noticed this week it didn't want to start, I thought it was either to fast or had advanced itself. Turns out the starter was bad.

Anyways, the timing mark on the dampner seems to have moved. We put a piston stop in and got close to finding the new TDC. Unplugged brown wire and set timing to 0. Plugged the wire back in and re-checked, timing now reads about 18 degrees advanced? Does anyone know if that sounds right?

Also, I need to find exact TDC. Going to pull shroud/fan and put a degree wheel on. Any other thoughts for this? Thanks guys.

Reggie

Well, the outer ring of the balancer on these things slip all the time... it's not unusual to not have the timing mark line up (I've started thinking the slipping may be due to to detonation, but that's just a theory right now). Which piston stop did you use? I've yet to find one that works with the angle of our plugs.. I made one, but that's a whole other story.
The degree wheel shouldn't be necessary if you're sure #1 is at TDC... if the outer ring has slipped, just make a new mark, then also make corresponding marks aligning the inner and outer rings (that way if it slips again you'll know it).

 

[WyoSyclone]

Re: Timing questions

More questions. Was just doing some reading about vacuum pressure. Sounds like it should be around 18 or so on a mostly stock truck? Mine is reading 12, that's at approx 900rpm while at idle. Truck has new vacuum lines.

Looks like another issue to work on.

You may have to look at your IAC counts on this one. If you've partially sucked an intake gasket your IAC will try to compensate by closing. 12 is low for a stock truck and I believe 18 is in the ballpark for a proper reading.

 

[WyoSyclone]

Re: Timing questions

I think there is more going on than just the timing. Got home after family stuff today and pulled the plugs back out, they have less than 100 miles on them.

1&2: Half of the plugs are soaked, oil I think. Other half is dry

3&4: Are wet, same as above

5&6: Are bone dry

??

Right now I'm going to get the timing set 100% at 0 and see if I've got a vacuum leak that's causing the low pressure. If I don't have a leak I think it's finally time to get some data.

Thoughts?

I would almost bet you've got a seal out in the turbo.. that oil can get sucked up into the intake and will readily deposit itself down into 1,3, 2,4. 5 and 6 are far enough away that they usually stay pretty dry. Take the tubing off between your turbo and IC and see if it's full of oil - if so, there's the problem.

Also take the oil filler cap off when the engine is warm and see if you have a bunch of fumes coming out of it... if so it could point to other issues.

 

[Monopoly]

Re: Timing questions

Thanks Rob! I'll take the tube off tonight and report back the findings.

 

[Monopoly]

Re: Timing questions

Well, the turbo is not leaking, the pipe is dry as a bone. Hoping this is not a bigger issue right now.

I do remember checking the oil fill for smoke/vapor coming out when I first looked at the truck and didn't notice anything major, then again I probably didn't get it hot enough.

 

[sy2207]

Re: Timing questions

More questions. Was just doing some reading about vacuum pressure. Sounds like it should be around 18 or so on a mostly stock truck? Mine is reading 12, that's at approx 900rpm while at idle. Truck has new vacuum lines.

Looks like another issue to work on.

If you are in denver then 12inhg isn't that far off from where you should be. Vacuum specs are usually determined from sea level.

 

[evberger22]

Re: Timing questions

Does fluidampaner make a balancer for these trucks? I went to check my timing and it seemed way off(line was approx 1/8 away clockwise from the 0 degree tooth slot). I disconnected tan wire and adjusted timing to what i thought was zero then truck would barely stay running. Even after I shut it off reconnected wire and started it back up. Could my balancer have shifted? Maybe skipped a tooth on chain? It runs fine when i turn it back where it was. I am going to verify TDC and check rotor and see where mark on balancer is at.

 

[socalblue]

Re: Timing questions

I had timing/idle issues with my truck too, and it turned out the harmonic balancer was bad causing rough skippy idle...