Still having some difficulty getting the 460 in my 74 F250 to run smoothly since re-installing the engine about month ago. Through the help of many of you on this site, I have fixed a few things that were causing some problems, such as the starter wiring and the distributor stator. But the engine still seems to idle rough, so much so that the truck vibrates a bit when accellerating. It also will stall out, but refire easily.

I put a new distributor in the truck last weekend, but not quite sure if I have it correct. Not sure if this could be the cause of the rough idle and vibration. I set the timing by taking out the #1 spark plug and rotating the engine until the mark was on TDC. Had to take several stabs at the distributor to get it lined up on the oil pump shaft, but I have it in and the timing set at 14 degrees. I had it at 12 at first, but did not notice a difference in performance between 12 and 14. Did I get the distributor in correct, or does the #1 cylinder have to come TDC more than once to consider it TDC. Does that make any sense?

Also, the connectors to the ignition box on the fenderwell crumbled in my hands the other day. so I think that may be the cause of the engine dying out intermittently. I'm going to put a new one on tomorrow to see if that halps.

If anyone can help with my rough idle and vibration issues, and if you feel it is related to now setting the distributor correctly, please let me know.

Thanks

 

did you try adjusting timing by ear? timing chains stretch and sometimes they wont run at what there suppose to be. When you cranking the engine over does it struggle to turn the engine? Sounds like timing is off but could be anything really.

 

Walk The cap sounds like you have a dead hole


Jason

 

Engine fires up right away, and it seems I have good power through low and higher speeds. I had checked the timing chain when I had the water pump and front cover off, and the deflection was less than 1/2 inch, which should be within specs. Are you saying it could have skipped a tooth, and now might need to be set more like 15-20 degrees or something to run without shaking?

Jason, not sure what walk the cap means. Are you saying the cap may have a dead spot?

 

Is there a TDC for a compression stroke and exhaust stroke? I've read some of the other posts, and I'm still wondering if my vibration problem is related to not setting the new distributor right. I have it timed at 14 degrees BTC right now.

I guess I don't know if when I turned the engine over to set it at TDC for the #1 cylinder, was that it's compression stroke, and I should have turned the engine around again until #1 came TDC again? I don't even know if this makes a difference.

If I have my timing correct, than I'm leaning towards the new flexplate not balanced well. I put a new one on from Advance Auto, so maybe it's just a little off on the balance. Is there any way to check if it's out of balance?

 

I've had someone at a local shop look at my truck and they seem to lean towards the flexplate not being balanced correctly. Had anyone had any problems with flexplates not balanced well from say an Autozone or Advance?

 

Just a thought, but if you have a flexplate that was internally balanced and your truck is externally balanced, it could throw off the balance of the motor. Like I said, it's just a thought.