I have a 1991 rs 3.1L v6. It ran rough for the longest time and i couldnt find out why. The other day it just died on me and i couldnt figure out why. i pullled a spark plug off cause i know its getting fuel and found out my spark plugs where bad so i replaced them. still didnt work. so i changed the spark plug wires and it fired right up. drove it to work and back and it ran like it was brand new, no codes came up or anything. The next morning i went to start it up and it wouldnt start. i am getting fuel and spark. when it tries to start it barely gets going and for maybe 5 seconds it runs but blows a bunch of smoke or exhaust out of my air intake. i have know idea why this is happening. my valves are moving, im lost if you have any ideas please help me out. thanks

 

timing chain

 

Thanks thats what alot of people are saying

 

Take out number one cyl passenger side. Plug the hole (I use paper towel in a ball) Tag it slowly when the towel blows out you should be at TDC. Then check you timing marks. It ashould be at TDC or close on your dampner.

If it off its your timing chain. Use this more than one. Say 10 times works everytime. Actaully went to a guys house on csascade crew and used this method. Worked and it was his timing chain.

 

Um... The damper is keyed to the crankshaft, so it will always be in the same position relative to the position of the #1 piston. The outer ring is what slips and makes the timing marks off when the rubber between the outer ring and the hub deteriorates.

To test the timing chain? Remove the dizzy cap and take hold of the rotor. Spin it to the left and to the right. Some slip is normal, but if you're finding it turns a lot, your timing chain is bad. Or, drain the coolant and take the water pump and timing cover off (probably going to have to do so anyways).

Sounds like another person needs to look at the "Look Here if you have a 90-92 3.1L V6" thread... Sounds ignition timing related. Try disconnecting the bypass connector and seeing how it runs.

 

What is the bypass connector and where is it?

 

The bypass connector is simply a one-wire connector, similar to the one for the O2S, that sticks out of the wiring harness near the evaporator housing (on the firewall), that is disconnected to allow base ignition timing to be set.

 

Also, check the ignition coil very carefully.

I had this exact problem with my old 90 bird with a 3.1 and automatic. I didn't figure it out until it was dark out and then we saw what was happening. Half the time, my spark was jumping through the side of the coil and arc-ing out on the coil bracket! I never would have seen that if it hadn't been dark. The place that these coils are mounted allows heat to build up on it and degrade it.

I changed the coil, and kept on going.

My 3.1 had 248k on it when I sold it and it never needed a timing chain, so I'm just saying.

 

On the crankshaft what are the timing marks