I posted in a couple weeks ago about my '89 K1500 that is in a crank no start. I'm back looking for more advice. I thought I had narrowed it down to a bad Ignition Control Module but after changing that out today it still wont start. I'll give a run down of what I've check so far.

1. I changed all the sparks plugs and confirmed I have spark
2. I took the fuel line off the back of the TBI, the pump is sending fuel and the pressure looked to be good. I did not measure the pressure but it's only supposed to be around 15 PSI from what I've read. The fuel looked good. It was not cloudy or dirty at all so the filter is good.
3. I bought noid lights and found I'm not getting any power to the pigtails for the fuel injectors.
4. I used a 9v battery to test the injectors and both of them reacted when I touched them with the battery so those aren't dead.
5. I replaced the Ignition Control Module

When I put gas directly into the bowls, the truck starts and will idle fine but the fuel injectors never fire. This truck ran well a month ago and has not been moved or used other than driving it up and down my driveway a few times since I got it in July. One thing I did notice while I was changing out the ICM was that the spark plug cables are not in the spots that the diagrams i've indicate they should be. Everything i've read said that #1 should be on the front left side of the distributor cap if you're looking at the cap from the front of the engine. #1 on mine is plugged in towards the back of the cap towards the firewall. I never took the plug wires off the distributor cap when I changed the ICM because there was enough play in the cables to not have to and when I changed the spark plugs I did them one at a time so I know I didn't mess the cables up when I changed the plugs. They're in the same order they were in when I got the truck and it will idle when you bottle feed it gas. I thought if the plug cables were in the wrong order it wouldn't start at all. I don't know if the fact that those aren't wired in the right order would somehow cause the injectors to not get power or if those are unrelated issues. My question about the spark plug cables is, is there any reason not to just move them into the right positions? I am so new at this that I'm afraid of messing it up ever more. I'm still at it and will welcome and new advice.

 

Logic would indicate that if it was running well when you bought it, the plug wires must be in the correct configuration, since it idles fine with fuel. Since you have OBD I, it is tough to find them these days, to run a diagnostic test. I'd check all of your fuses and relays first off. Make sure all the wires are okay, no corrosion, or wear. I use dielectric grease on all my wiring plugs to keep water out. It could also be the crankshaft sensor is bad, or wiring. At worse you may have a bad Electric Control Module (ECM), IMO.

 

It is also possible your "new" ICM is bad. Don't change your wires around. You say it runs with fuel added to the throttle body. Need to concentrate on why the injectors are not firing.