Engine/Transmission (1994 - 1998) Timing Trouble, Please Help!!!!

[sstockton]

Okay, so at the beginning of tonight, we set out to time my friends 96 12v. followed directions to a t. The first time around, we didn't get the timing quite as high as we had wanted, only 14. 5* and so we decided to go a little bit higher. Now when we crank it up to around 16. 5 degrees, 6. 5mm of travel on the dial indicator, when we pull the timing gear off the shaft, the shaft rotates and the dial indicator drops more than 3mm, leaving us at roughly 7 degrees timing. Has anyone had this happen or heard of this happening? Is our dial indicator broken or does the shaft have that much tension on it, that it is slipping back.



Also, when we first measured the amount of movement we had, before trying to time the truck, it was only 3. 66mm which is almost 0 timing. Might the timing have slipped that much. The only problem the truck is having is that it smokes a lot, and doesn't get great milage.



Mods, #0 fuel plate, AFC, 3k GSK, Starwheel, turned a little, and 370's.

What can we do from here?

Thanks guys.

Sean

 

[JoshPeters]

Next time you guys go to pop the gear off, leave the nut and the washer on the shaft. Spin the nut out till it is flush with the tip of the shaft. That will help keep some tension on the shaft that way it doesn't pop back like that.

It pops back due to the tension on the cam inside the injection pump is the reason it is rotating back.

JP

 

[JGK]

I've experienced that on a 215 pump.



Try cracking the retaining nuts on all the other injector lines at the pump to let the pressure bleed off any pressurized lines. That made a big difference for me. Between this and what Josh suggested, you should have better luck. Also, after initially popping the gear loose, and after cleaning the shaft and gear hub with brake cleaner, when snugging the nut to set the gear temporarily on the shaft so you can rotate forward up to your desired timing, you only need about 1 ft-lb of torque on the nut to get the pump to rotate. Then when the gear is popped loose again to rotate back, then up to TDC, the pop isn't so violent.



Be advised it will move just a tad anyway, either when the gear is popped or when you torque the nut. But generally only by a few 10ths mm at most.



-Jay

 

[paulb]

On a 96 with a 180 pump, isn't 16. 5*, about 5. 0mm?



Paul

 

[sstockton]

On a 96 with a 180 pump, isn't 16. 5*, about 5. 0mm?



Paul

I was going based off another chart I had read. I thought that 6. 5mm was 16. 5 degrees. Someone please let me know if this is the case or not. we were able to get it, to 6. 5mm and the truck seems to run really well and drive fine, with less smoke at idle and lower egt's.



anyways, we tried cracking the other lines and also not pulling the nut off as far, we had never fully removed it and it still kept springing back. So essentially what we ended up doing was calculating the lift difference between what we had and what we needed, then measuring the travel required to obtain this on the harmonic balancer. From there we just measured how far back we needed to rotate the harmonic balancer from TDC, popped the gear off at TDC, rotated back to our mark, set the gear and rechecked everything. After torquing we ended up having our desired lift, so it seems like it all worked out alright.



Sean

 

[Lonestar]

Is the truck a standard or an auto? The standard transmission would be a 215hp pump, (6. 5mm) if it is an auto, it will be a 180hp pump.



KEEP ON TRUCKIN'

Lonestar

 

[sstockton]

Yeah, its an auto, thats what we were basing it on.
Sean

 

[paulb]

Yeah, its an auto, thats what we were basing it on.

Sean

It should be a 180hp pump then, and the lift for 16. 5* would be about 5. 0mm. What is the CPL number on the pump?



Paul