1998 k3500 7.4l wont start

Not open for further replies.
Oct 11, 2017
I am having trouble starting my 1998 k3500 7.4l dually. One day it just shut down. Wound up being the coil. I replaced it and drover her for about 2 weeks. She shut off again. Thought maybe it was fuel pump. I replaced the fuel pump nothing. Replaced the coil again. Nothing. I replaced the camshaft postion sensor. I also replaced the crankshaft position sensor. I replaced the rotor and distribitor cap. I also replaced the ignition control module. Also the fuel filter. I am getting beautiful spark and plenty of fuel pressure. I am at my wits end with this truck and i cant think of anything else. Also i replaced all 8 spark plugs. I checked the timing by putting her at tdc. I also checked the maf sensor and map sensor. Please if anybody has any info please help...
Spark to all cylinders? Injectors pulsing? Squirt some fuel down the throttle body and see if it tries to start.
I know on TBI engines there’s a bulb you can plug in to see if the injectors are getting power, not sure on the Vortec engines. Someone on here will probably know, might be able to just use a test light while cranking.
I forgot to mention the only code showing in the systmem is p1351 which is high voltage to icm but its a brand new oem icm i put on and nothing but the code keeps popping up everytime i clear it
sounds like a possible wiring issue. What fuel pressure do you have? does it hold fuel pressure for at least a few mins? Sounds like maybe its time for it to go to someone with better tools and troubleshooting guide.
Originally Posted By: jubinjr
I took it to a mechanic shop and they are the ones who told me to replace the icm and spark plugs.
Well I hope you get your money back then because it didnt fix it.
Well i did the work myself. All they did was kind of diagnos it. Im just trying what else could be causing this issue. She sounds like she wants to fire but wont
My friend has the same engine. The problem he had turned out to be a hole in the main spark wire from the coil to the distributor leaking sparks out. A test plug would fire outside the engine, but it was not enough spark to start it. If you can't get it to fire at all on starting fluid you should take a close look at the ignition parts, which as you know are very hard to see where they are way at the back of the engine. Throwing codes related to the interface between the PCM and ICM could be a problem with the low voltage wiring, or even a bad PCM.
Last edited:
a bad coil wire can cause an insulation failure in the coil. gets a gap burned in it that has to be jumped which causes overshoot. you can get a spark with the plug out that is too weak under compression. spark too weak or worse jumped timing. have also seen rotor button arc through.
Not open for further replies.