Odd no start issue

DIESELMAFIAPER.LB7

<----new hotness
Jan 17, 2010
5,163
12
38
idaho
shop.dieselmafiaperformance.com
So been a day two since I've posted here but I'm fighting a lbz got a long block for a customer installed in a lbz.

The truck throws a crank sensor code p0336 but I'm seeing 165-195 rpm cranking. So sensor can't be backward. Sensors worked perfectly prior to replacement. Truck was running when it came in and now has a new motor, fuel system, turbo ect ect.

I'm building fuel pressure up to 11k then it drain down to 2k while extended cranking is going on....

I'm stumped I've checked all the grounds(I cleaned the surfaces of the new long block prior to install) even re flashed the ecm all that is fine and looks good. Going to swap a sensor but it's the only damn code I have and I can't see it being a sensor where I am reading rpm.

Curious if anyone had ran into this. The truck acts like it's not getting a signal to fire somehow.
 

akuz

New member
Feb 12, 2022
5
0
1
what ive seen before in my experience - similar situation.

Replaced the cps - still no start - checked all wiring checked everything.
Found the alloy plate that mounts to the engine block where the sensor bolts into was corroded on the back.

Replaced the plate and the truck fires right up.

Maybe it can help someone as this took me quite a bit to figure out.