help please

[st8pipe350]

89 1500 pickup 305


my mom was driving one day and it just died. she cranked it and it backfired she cranked it again and it started and was just putin down the road. well this was about 8 months ago. my dad has messed with it, i have looked at it. we cant figure anything out. we figured it jumped time. so we pulled the front of the motor apart and guess what., it jumped 2 teeth. woohoo we replaced the sprockets and chain, set it in time and....... Nothing. wouldnt start. will crank all day but not start. so my dad started turning the distributor around. 180deg-360deg. i told him to stop but he wouldnt listen. so obviously it is out of time. well my sisters b/f is in the process of having his turn with it. but it is looking unsuccessful aswell. but i want to fix it for my mom. i mean come on she has done everything under the sun for me. so i feel obligated. but. he bought a new distributor and put it in. pulled out cyl 1 plug and got the piston to TDC and put the dist back in. cranked it and it backfired like a M.F. lol loud as hell. so he pulled it out and put it back in about 50 times just trying to get it set right i guess, not real sure. but everytime he cranks it.... it backfires. the exhaust is now blown off the truck. muffler has been blown inside out. LITTERALLY i will post picks soon..lol but could someone give me some light on this project? i guess i need to know exactly how to time the motor from start to finish. or some ways of testing to see what is wrong or soemthing. please help me..... my email is [email protected] email if you want post on here i dont care.i just need advise. thanks logan

[jdmccright]

I'm hoping the timing jump didn't cause damage to the pistons or valves via interference. Run a compression or leakdown test. I'd also check the plugs for fouling, corrosion, and proper gap. Check the wire resistances too.

The procedure for installing the distributor is given below:

Engine Not Disturbed

1. Install the distributor in the engine making sure that the matchmarks (between the rotor-to-housing and housing-to-engine block positions) are properly aligned.
2. If the rotor-to-housing and housing-to-engine marks are not aligned, the distributor gear may be off a tooth or more. If this is the case repeat the installation process until the marks are perfectly aligned.
3. Install the hold-down clamp and bolt, then tighten the bolt to 20 ft. lbs. (27 Nm).
4. Install the distributor cap and attach the electrical connector at the base of the distributor.
5. Attach the spark plug wires and coil leads.
6. Connect the negative battery cable.

Engine Disturbed

1. Remove the No. 1 cylinder spark plug.
2. Turn the engine using a socket wrench on the large bolt on the front of the crankshaft pulley. Place a finger near the No. 1 spark plug hole and turn the crankshaft until the piston reaches Top Dead Center (TDC). As the engine approaches TDC, you will feel air being expelled by the No. 1 cylinder. If the position is not being met, turn the engine another full turn (360 degree). Once the engine's position is correct, install the spark plug.
3. Align the pre-drilled indent hole in the distributor driven gear with the white painted alignment line on the lower portion of the shaft housing.
4. Using a long screwdriver, align the oil pump drive shaft in the engine in the mating drive tab in the distributor.
5. Install the distributor in the engine.
6. When the distributor is fully seated, the rotor segment should be aligned with the pointer cast in the distributor base. The pointer will have a "6" or "8" cast into it indicating a 6 or 8-cylinder engine. If the rotor segment is not within a few degrees of the pointer, the distributor gear may be off a tooth or more. If this is the case repeat the process until the rotor aligns with the pointer.
7. Install the cap and fasten the mounting screws.
8. Install the hold-down clamp and bolt, then tighten the bolt to 20 ft. lbs. (27 Nm).
9. Engage the electrical connections and the spark plug wires.

If its still back firing, then you should check the air injector reactor (AIR) system for leaks or valve failures. Below is a check procedure from the online repair manual:

http://www.autozone.com/shopping/rep...00c1528008f061

Good luck!