Truck jumped timing, need some help please

[Mychael101]

The truck is a 97 GMC 1500 5.7l and the distributor hold down plate became loose and was letting the distributor move a bit. Anyone near Keller and have a scan tool they would be kind enough to let me use for a half hour so I can get the distributor back to its proper alignment?

[JC316]

You don't need a scan tool to set it. Just set the engine the no.1 TDC and then align the rotor with the number 1 spot on the cap, the computer will do the rest. The timing is automatic in those years.

[BP]

You don't need a scan tool to set it. Just set the engine the no.1 TDC and then align the rotor with the number 1 spot on the cap, the computer will do the rest. The timing is automatic in those years.

True but you'll get a P0340 code if it's off by 2 degrees. The crank sensor doesn't read until it's at 1000 rpm so as soon as you go on a test drive the SES will come on if it's not very close to perfect.

What I did on my truck was move it ever so slightly in one direction, clear the code and drive it. If it came back then I moved it slightly more the other way. I miss having a Tech2!

[Mychael101]

True but you'll get a P0340 code if it's off by 2 degrees. The crank sensor doesn't read until it's at 1000 rpm so as soon as you go on a test drive the SES will come on if it's not very close to perfect.

What I did on my truck was move it ever so slightly in one direction, clear the code and drive it. If it came back then I moved it slightly more the other way. I miss having a Tech2!

Yup, I'm trying to avoid hunting down the sweet spot by trial and error. I'm thinking turning it counter-clockwise is to advance, can anyone verify this? I may just hit up the local parts store and see if they will let me use the scanner for a few minutes.

[BP]

I mistyped, the cam sensor only reads at 1000+rpm. Just make sure the rotor is pointed exactly at the #1 spark plug at TDC with the mark on the balancer at zero. Then move the distributor until the rotor is pointing at the mark on it. You'll be within 2-3 degrees either way.

I'm fairly positive you go clockwise to advance it, that's the direction the distributor turns so to advance you move it more clockwise.

[Mychael101]

I mistyped, the cam sensor only reads at 1000+rpm. Just make sure the rotor is pointed exactly at the #1 spark plug at TDC with the mark on the balancer at zero. Then move the distributor until the rotor is pointing at the mark on it. You'll be within 2-3 degrees either way.

I'm fairly positive you go clockwise to advance it, that's the direction the distributor turns so to advance you move it more clockwise.

There are no marks on the balancer, and I marked the position of the rotor when i took the cap off. I thought I had it but it's the same. Occasional hard starts and occasional missing but no codes. I may just bite the bullet and pick up a code reader or take it to a local shop.

[kdventura73]

I have never used a scanner. If you look at the dist base under the rotor you will notice two small triangles molded into the base. One it be marked 8 and the other 6. Set the motor to tdc and align it to the one that says 8. I will place the rotor on to it once I know which triangle to look at to see if it is aligned

[shumpertdavid]

There are no marks on the balancer, and I marked the position of the rotor when i took the cap off. I thought I had it but it's the same. Occasional hard starts and occasional missing but no codes. I may just bite the bullet and pick up a code reader or take it to a local shop.

The balance should have a small mark and the timing cover a raised spot, I believe rotated to the drivers side from the center of the water pump. Finding TDC on a 96 up can be a pain in the ass.

[dee]

The balance should have a small mark and the timing cover a raised spot, I believe rotated to the drivers side from the center of the water pump. Finding TDC on a 96 up can be a pain in the ass.

What's nice is when the distributor shaft is twisted and you get a nice CMP code that won't go away without a new distributor.

[shumpertdavid]

I've not run into that one yet, Hope that I don't ever see it either lol.

[BP]

What's nice is when the distributor shaft is twisted and you get a nice CMP code that won't go away without a new distributor.

Those distributors are very easy to rebuild but then again they aren't that expensive used either.