I'm hoping somebody on here can straighten me out. I tried to check the timing on my '95 12 valve today. I bought the sp500 timing kit from snapon. According to the service procedure, if I understand correctly, I should have 12.5 degrees, or 5.7 mm of lift. When I set the gauge up, I get about 7.4 mm of lift at the fuel plunger. I was going to advance it to 15 degrees, or 6.2 mm. But I'm already reading 7.4 mm, so now I'm really confused. I checked the CPL no. on my engine and it matches the chart I'm useing. My truck is a 95 3500 with 170000 miles, and the timing hasn't been messed with before. Can somebody tell me what I'm doing wrong?

Thanks, Barry Franklin

 

I'm not try ing to hijack your post and I hope someone answers you but what did the timing kit cost ?

 

With shipping it came to 242.05............but it came witout a barring tool.

Barry

 

Anybody got any ideas on this? I'm probably doing something wrong, but I don't know what.................................

Barry

 

1. find tdc of number 1 cyl and mark
2. setup dial gauge so it reads about 8 mm
3. rotate motor BACKWARDS till dial gauge stops moving
4. now zero the dial gauge
5. turn motor forward and stop at TDC mark raed the gauge

is this how youre doin it?

anyparts you dont understand or are confused on just ask

to turn motor bacwards use ALT pully nut

to go forward I use dampener pully bolt

 

That's the way I'm doing it. Why am I getting such a high reading?

Barry

 

You're timing could have slipped and you were sitting at 15 degrees or whatever to begin with. It happens.

 

Can the timing slip in either direction? My timing seems to be advanced, according to the chart from Geno's website. But the engine runs like the timing is retarded. Could it slip in the advanced direction?

Barry

 

I've heard of timing slipping in the advanced direction. The more you advance timing, the less low-end power you have. Maybe that's why you think the timing is retarded, when it really isn't.

 

maybee someone was in there messn around before you got the truck..

 

I might try to retard it some and see what happens..................I am really confused right about now.

Barry

 

Did you check the timing by pushing in the timing pin? If so, that could cause false readings also. The timing pin is not accurate enough to set/check timing.

 

hi
mine was advanced when i checked it ,prob about 21*

i set it at 16.1 , cant say i see much diff ???

 

use the timing pin on the side of the pump to set the pump to 12.5 deg then pop off the gear and set motor to tdc ... now youre set to factory spec 12.5 deg, this way you can sheck timing with youre gauge and see if you are doing it correctly... just an idea

 

Well, I checked it again today, and it was set at 23 degrees. I backed it off to 17 degrees. It seems to run a littlle better, but not a big difference from the way it ran before. Still has a flutter under light acceleration at about 1200 rpms. Not really a miss, just kind of bucks a little. If I accelerate hard it smooths out, kind of a dark grey smoke. I have the star wheel set about halfway. Would it help to run it one way or the other? It really does have a lot of power, but something's still not right. And I do want to thank everybody that responded to this thread. It really helped me a bunch.

Barry Franklin