just a thot that may not apply - a few years back I had a Chevy pickup in my shop that sometimes would fire up like a top other times back kick as if out of time - complete tuneup, checked timing chain, ecm, ect, ect, ect. right about the time I had my head all bloody from beating it on the wall in frustration while I had the dist out for the uncounted time i noticed a small crack in the magnet on the dist. shaft for the stater, when the crack opened a tiny bit it sent a double pulse and did it's out of time no start, when the crack pulled itself together fired like a champ - I know that the PO said he replaced the dist. BUT just a thot

 

Odat, I Know exactly what you're talking about with the pick up coil in the distributor. The broken wire can be a real PITA to diagnose. The OP's is a 1999 and it has EDI. Only thing in the distributor is the camshaft position sensor, and it has nothing to do with spark. You can unplug it and the engine will start & run just fine. Cylinder misfire detection and identification will be disabled, that's it. Keep the ideas coming, without looking at it, hearing it, and laying hands on it, the word "challenge" comes to mind.

 

Wouldnt this be doing the same thing as we have done before when checking dist. Timing?

 

In theory yes, I just want to make absolutely sure #1 piston is at TDC compression. Short of removing the rocker arm cover, this is the way to do it.

 

Ok did that and rotor is pointing at the 6 on dist

 

Found out two things found reason why wouldnt fire. Found yellow wire going to the ignition for the security was rubbed thru causing short out and throw code for security. Got it almost idling and still hear knock so pulled off valve cover on passenger side. Cranking engine over and knock is internal the way it sound like a bent connecting rod

 

The yellow wire at the lock cylinder sensor is the data line from the BCM to the PCM. If it shorts to ground, or has an open circuit, the BCM will not allow the PCM to fire the injectors. One of the tests was to crank and see if fuel pressure drops, and it did. Intermittent and odd.


A bent rod could definitely cause a knock. Just seems mighty odd that it only knocked with the ignition enabled. What are the chances of partially bending a rod???? Every rod I've seen bend, locks the engine up, or tosses it out the oil pan. Must be the added pressure on the piston from combustion was enough to make it knock and bind while cranking the starter. Good job finding that, and sticking with it.

 

rod bearing? usually if you pull the offending cylinder plug wire the knock will quiet down - inless it's like the 4.3 we had to put a bottom end in - before rebuild it held 50 lbs of oil pressure and it didn't quit rattling no matter what plug wire we pulled or what we did - had no idea how bad it was till we tore it down - 6 rod bearings 2 mains