Hi I'am new to the forum so please bear with me. I have a 1994 b3000 with the 3.0 liter engine w/ 5speed manual trans 2 wheel drive.It has 140000 miles on it and runs OK.Every so often after a short hop 1 mile or less after the truck is warmed up it won't start ( no spark) It started out doing this every few months or so now it's almost every day .I have replaced the coil ,cap plugs and wires.
Anybody have any Ideas? Thanks Chuck ore

 

If it's intermittent, look for a weak ground. At the starter, battery or engine block

 

I left out the engine turns over fine I get no spark to ingnition

 

OK...so your starter is grounded fine. Double check your engine ground (there should be a strap going from the block to the frame somewhere.) as well as the ground for your coil. No spark means the circuit can't complete itself (Assuming that the new parts you bought are all good. I've had brand new parts be bad before.) If you see corrosion on any of these wires, unhook them, clean them off, clean off the spot they interface with the body (metal bristle brush works) and reinstall.

I was working on a fuel injection system for a marine Big Block for a school project trying to get it running (the school I was going to had a fortune invested in it and it never worked.) My friend and I ended up tracking the problem down to the ECM (Fuel controller). We ordered a new ECM (very expensive part) to replace the original new ECM, only to have it still not work. We went through the troubleshoot again and came up with the same conclusion, bad ECM. We rec'd the 3rd ECM, installed it and the motor cranked up like new.

 

Well I cleaned up the ground and checked all connections.The problem has been gotting worse .The last 2 times I've used the truck it won't start for several hours after I shut it down it nearly has to be stone cold to start.Then it fires right up and runs fine.Ideas???