3406E wont start

Your borrowed ecm has a differnt tach calibration in the ECM, it a changeable parameter set to match the tach in your particular model truck. you need the tach calibrtation number out of your old ECM put in your new one, that will fix the prob.

 

This problem sounds similar to one I been trying to deal with on a C15. Now this happens very rarely, only 3x in the last year. Shut the engine off to re-fuel or something like that, finish fueling and then no start. Then after 1/2 hr - 45 min it will restart and run fine. Would a cam sensor be intermittent?

 

I have heard it said that if a cam sensor is going bad, and the truck shuts down, as soon as it cools off, the truck will start back up. I also was told that a way to tell if their bad is when the lose their magnetism. All this is hear-say, but I do know that a Cam senser is around 100 dollars, so maybe just pick one up and carry it along for safety sake. I carry a extra cam and crank sensor. Very easy to change..take longer to raise the hood than to change the sensor.

 

Hi Randall: Had a cam sensor go bad once. Was pulling a fairly steep hill and truck started skipping etc. for a few seconds then it died. Finally restarted after a minute or so. Ran for about 5 more minutes and then completely died.

 

I picked up another cam sensor and installed it. I will wait and see what happens. I may install a fuel pressure guage as well.

Thanks for suggestions.

 

Hmm,, I do know for certain if the Cam sensor is going bad, you can unplug them and the truck will run just fine without it... You have to get it started, and dont shut it off or it willnot start without it pluged in, but once you get it going just reach in there and unplug it and your good to go.

 

You also have a crank senser below the cam senser, should be 2 wires that run straight down from cam senser wires that will track to the crank senser...Crank senser looks just like the cam, but alittle bigger. Check the wires also, they sometimes will break off inside...usually right at the plug end of the wire.

 

one thing I have noticed when an ECM is fried is.....
when you turn the key on and put your head right down near the ECM and listen you will hear a high pitched squealing sound (its hard to hear listen carefull)
every time ive had a truck where the injector driver is dead in the Ecm it has made this noise
also
when priming the fuel system if you take the return fuel line off the fuel filter housing and pump it untill fuel comes out nice and clean (with no air) and then install the fuel line back on and pump it untill the primer gets hard again (make sure its the line that goes from the cylinder head to the fuel filter housing)
ive had very good luck primimg and starting this way
usually when replacing fuel filters i spin them on dry then i remove the return line and pump untill fuel comes out
its always starts right away with no missing
......... although it takes a fair amount of pumping to fill both filters its nice and clean way of doing it and all the fuel is filtered going to the injectors