Ai 400 Extended Crank Time

[DieselDog5.9]

Sometimes turn the engine over and it starts right up, sometimes crank it over multiple times before it will take off.  Changed the fitting on the side of the block thinking it was not holding fuel pressure, acts like a check valve that is not holding its prime.

[Onyx610]

When does it have extended cranktime? Have you checked oil level? Maybe check the fuel pressure once you know it’s gonna  start acting up? Maybe it’s a crank position sensor…could be alot of things. 

[Joey Mack]

Just for kick's....  look at the cam sensor plug and socket (eng. position sensor) Do the same for the crank sensor (R.P.M./ T.D.C. sensor)  look for fraying of the wires where it goes into the plug. The R.P.M. sensor may have a 3 pin plug with only 2 wires.. you can also, un-plug one of them and try to start the engine, it will crank for a few seconds before starting, and will run rough when it starts.  then plug it back in and un-plug the other sensor, and crank it up.  if it does not start, the sensor that Is plugged in is bad.  These engines can run on either one but uses both to balance it out.. Just one of my "off the wall" test's.. Let us know how it goes... jojo

[DieselDog5.9]

Seems to be random, one morning it will fire up right off, another it will crank for a long time.  And warm or cold makes no difference.  I did pump the primer hard one morning when it was doing it and no difference which had me scratching my head.   I will look into the sensor issues, are the cam and crank sensors easy to locate, assume the crank sensor is above the harmonic balancer?

[Joey Mack]

easy to see...cam sensor is at the  right front near the breather.  held in with an 8mm bolt. short harness, secured on the edge of the timing cover.... the crank sensor is at 8 o'clock on the flywheel housing... the cam sensor may have a teardrop shim behind it.  just for kicks, take it out and put it in youre pocket..  put the sensor back in, then  crank the engine and see if it runs better..