99 Vortec 454 Timing Issues

[72k20Farmtruck]

I've got a vortec 454 out of a 99 suburban we swapped into a 1982 6.2 diesel truck. We used Howell Engineering's harness and ecm. Changed injectors a few weeks ago because of hot injector leak, typical issue. Been driving the truck a lot and we've been happy with it so far until earlier today I was at a stop light towing about 8,000 pounds when I started to take off the truck sputtered and died. Tried cranking and cranking and it keeps backfiring through the exhaust. Acted like the timing went fully retarded. Anyways we got er back to our shop and I changed the coil because that's the only ignition piece unchanged and still backfiring through the exhaust. This time it backfired so loud I went deaf for a good few seconds. Ears still ringing. Here's a list of what we've done previously:
Spark plugs
Rotor
Cap
Ignition Control Module
Cam Sensor
Crank Sensor
Coil
Injectors

Motor had about 140,000 miles on it before the swap so I can't imagine the timing chain jumped. All help is appreciated I would like to make this truck work again it's been a really fun project and a great work truck. Thanks!

[b454rat]

I had a 97 with the 454 in it that I sold to a buddy. His did the same thing. The gear on the bottom of the distributor was wore down. The pain is timing, need a computer do to it. IIRC only allowed 2 degrees for it to even fire, which I guess isn't much.

[speedygonzales]

You may want to be sure the timing of the distributor is near where it should be by setting no1 to TDC and checking the position of the rotor.

I'm going with Rat, I see way too many people use the wrong distributor gear and wipe it out. Check the position of the rotor.

Grab the rotor and see how much play it has.

[72k20Farmtruck]

Thanks guys I will go ahead and pull the distributor tonight and I will let you know how it looks.

[72k20Farmtruck]

Ok well pulled the distributor because it was not spinning, drive gear was chewed. Bought a new remanufactured distributor and now I can't figure out how to time it exactly. No timing marks on the dampener. Any tips?

[speedygonzales]

Put No. 1 at TDC

Be sure you are on the compression stroke and not the exhaust stroke. I like to put my finger over the plug hole as I turn the engine by hand to be sure air is forced out past my finger. This indicates you are on the correct stroke. Once you are close, you can use a small wooden dowel in the plug hole to see when the piston is at TDC.

After you align that, you want to align the mark on the bottom of the distributor with the simple on the gear. See the picture. The dimple at the bottom is lined up with the paint mark above. When this is lined up, the rotor is pointing to the "8".

http://i1371.photobucket.com/albums/...g?t=1467545852

Be sure the pump drive is lined up for the slot in the distributor gear.

Now keep the marks lined up on the Dist as you drop it in place. Once it's lined up, the rotor should face the "8" printed in the top of the distributor body. Obviously you have to have the cap off the dist. to see the "8".

Once that is done, you have to have it scanned for cam retard offset. It's a correlation between the cam sensor in the distributor and the crank sensor.

[72k20Farmtruck]

Thanks i will let you know how it goes

[72k20Farmtruck]

Happy 4th, Well, got it to fire. But it's running absolutely horribly. Is there any way that it can fire one tooth off? I can't get the motor to rev or anything. My only other guess is that I have a major vacuum leak somewhere. Thanks.

[speedygonzales]

See post 6 again

[68C15]

it sounds like it may be a tooth off. Try putting it in again. I use the cap to find exact position of #1. Follow the mole trail from wire terminal to where #1 actually is then mark that on dizzy with marker. Place rotor pointing at that mark, hold dizzy in one hand, use finger of other hand in center of one tooth groove and turn gear by moving finger down gear groove. This simulates pulling dizzy out of engine. put second mark where rotor points now, this is your installed target. I usually put second (target ) mark on plate inside dizzy. Install dizzy with engine at #1 TDC and rotate dizzy until rotor points at second mark. This method gets me within 10 degrees, many times within the needed 2* +/- window. Then take it to a shop with scan tool and adjust "cam offset". This is done with engine above 1000 RPM. "Cam offset" is a calculated difference the PCM sees based on cam position sensor, crank position sensor and RPM

[68C15]

Originally Posted by speedygonzales

See post 6 again

his reman dizzy may not have a paint mark