injection pump timing

[84cucv1ton]

hi truck is a 87 m1008. new injection pump and injector's... 3 1/2 " exhaust, custom intake get outside air from 2 spots and he did some port matching for more power. he lined the pump up with the timing marks moved it about 5/16 of a inch... im thinking that may be to much. know what i mean? more air flow, raise the fuel going in..

thought i would ask before we turn the key.. any advice? thanks

 

[Cucvnut]

If you think its to much put it back to stock.hopefully some one who knows more will chime in.

 

[BIG_RED]

Agreed. Unless "He" used a timing device on it, put it back to stock timing before starting it - and go from there by how it sounds.

 

[84cucv1ton]

i was thinking 1/4" to start. if its to much im not sure if it will be damaged. thats what worries me

 

[84cucv1ton]

lined up the stock timing. started great. runs and sounds good.. seems to put out very little smoke.

 

[BIG_RED]

Good to hear.

 

[dstang97]

Move timing mark 1/16 to drivers side and turn the pump up by 1/8

 

[TGP (IL)]

Be very careful about advancing the IP beyond the marks.
The marks are most often correct.
However if you suspect there off you need to have a timing light set up for diesels, to set to spec then remark.
So many people think you can rotate the pump a little(advance) and your go to go!
WRONG!
Yes will it will appear to run better,more snappy, but your beating the lower end out of it.
It will break the crank and, or the block at the main web.
5/16 as you said would have killed it.
You were smart aligning the marks as intended.
Ask me how I know lol
Learned that lesson 25 years ago.,
Tom

 

[rickf]

Timing changes on these are measured in thousandths! I advanced mine the width of the line and that was more than enough.

Rick

 

[84cucv1ton]

Move timing mark 1/16 to drivers side and turn the pump up by 1/8

that seems to do it! puts out very little smoke still... just waiting on the turbo

 

[acesneights1]

I have worked on many many 6.2's and what Dstang said is pretty much the norm. If they were all meant to be set with the marks lined up, then why have it adjustable at all. I intend to do a full thread on timing hopefully next weekend with a Timing Light. The proper tool was made by Kent Moore specifically for 6.2 diesels and the Mech IP 6.5's. Good luck finding one. Snap on also made one. it was the MT480. Again good luck finding one. I was lucky and have a Snap On Mt480. Kent Moore also makes a tool called a Tach n Time but I could never verify if that would work also. Remember Timing chains stretch and the IP is driven off the cam so some advance can be necessary. To time it by ear is really just experience. it's hard to explain it. It should sound a little loud like marbles under light acceleration and get a little quieter under heavy. If it's loud under heavy accel you are too far advanced. 5/16 is definitely way too far. I have never had to bump one more than a match book covers width and that is with a 300k motor.

 

[84cucv1ton]

thanks like to read the timing post when the time comes.. runs good. feels a lot better then what it did must have been tired.. 6.2 has 18k on it. probably lots of idle time.. took me a long time. 3 1/2 hours just for the pump and injectors. it got done tho.

 

[jdeoliveira74]

Question.. My truck was running really loud so I changed my injectors it seemed a little better but not right. I just retarded my timing and the truck quieted right down. I had to move it about 1/8 of a inch to the passenger side of the truck. I this a early sign of injection pump failure??