Originally Posted by Ded0nfeet
Hello all, here's what I'm dealing with, 95 chevy 2500 with a tbi 350 and a 4L80E trans. Engine was replaced along with TB, distributor, cap, rotor, wires, plugs, battery, and starter. All of the work was done by someone else and was done before I got the truck a couple of days ago. When I first started it it cranked right up with an "ok" idle, when I put it in gear I could tell the timing was wrong because it would ping an knock even under a slight load, so I babied it 4 out of the 5 miles I needed to go then it died and now is extremely hard to start if at all and will not idle at all. I've set the timing at 0 with the brown/black wire disconnected with no luck, the only engine related fault code I get is 43, the scan tool said "ks problem" I'm guessing the knock sensor, would this keep the engine from running? What else should I look for? The spark seems intermittent or incorrect, if the dist is set at 0 it doesn't even try to start, if I rotate it clockwise as viewed from the top (about 1/3 full rotation) it starts and runs fairly smooth as long as I keep the pedal down a little, let off and it dies. This thing has me pulling my hair out, any help would be GREATLY appreciated!
Code 43 is for electronic spark control which does incorporate the Knock sensor.Some scanners kind of "abreviate" the code description and it can be confusing.
A code 43 sets with the tan/black wire disconeccted while setting timing.
Try clearing it and restarting the truck to see if it comes back.
Also if the timing was set at zero and you turn the distributor clockwise to get it to run, you are retarding the timing.turning the distributor 1/3 of the way means the timing is way off or the timing marks on the balancer are wrong, like incorrect balancer, or the outer ring has slipped.Also using the wrong plug wire when using the timing light will change the reading you get.Were you on the number 1 wire? Maybe you were on the number 2 wire?
They are next to each other on the cap back there and that would throw the timing marks way out if you were hooked to number 2 instead of number 1.
earlier models had a seperate spark control module, your truck has the electronic spark control built into the Ignition Control module.(inside the distributor)
The fact that when you get it to run OK but still not Idle makes me think you have a problem with the idle speed controller also.But the timing needs addressed first.
First thing to do is sort out the base timing issue, check the installation of the distributor make SURE you are on TDC #1 and compression stroke.do your best to get the piston at the top of the stroke so you can kinda gauge whether or not the balancer timing mark is right or if it has shifted.
Then get the distributor clock posisition correct, then be sure plug wires are on in the right tower and sequence, you know 18436572.
Attempt to set the static timing then at 0 degrees,then reinstall cap and wires and restart, be sure to clear the code 43 and have the tan/black timing wire connected . If it still runs crappy and sets the code,try unplugging the knock sensor to see if it changes anything. Then post back here.
The problem you have sounds compounded by a few things and you will have to start with the basic checks to sort it out.then go from there.