No tach movement when cranking

[6speedsd]

Truck is an 03. Have had an issue with long cranks when cold before its running. Noticed today that the tach doesnt come up at all when cranking. Not even a flicker. I know it's supposed to come up some while its turning over. What could be the cause of it not?

 

[Andrew]

Crank sensor would be a guess but getting a scan tool on it would help a ton.

 

[webb06]

Crank or cam sensor most likely or the wiring harness to either sensor

 

[6speedsd]

Crank sensor has been replaced. Maybe 6 mths ago. No codes come up with AE. Was thinking cam sensor personally but wasn't for sure.

 

[webb06]

Can you monitor the "sync" pid on AE? If it toggles to yes when cranking then the crank and cam sensors are ok

 

[6speedsd]

I've checked it before. I "think" it stayed on no, but don't hold me to it. I do know that when its running, it constantly goes from no to yes, no to yes. Like it'll be on no for a few seconds, then change to yes for a few.

 

[Gary]

Can you monitor the "sync" pid on AE? If it toggles to yes when cranking then the crank and cam sensors are ok

:whs:

 

[Jarrod B]

thought that was a 7.3 thing. cause my 03 6.0 never moved when cranking.

 

[webb06]

thought that was a 7.3 thing. cause my 03 6.0 never moved when cranking.

6.0's do it too

 

[6speedsd]

I'll have to put AE back on it and see what happens. Honestly can't remember what it did last time.

Another thing is the oil gauge on the cluster doesn't come up either. I've always heard if it doesn't you have a lpop issue. I pulled the filter the other day and checked there while cranking and it started filling as soon as you start turning it over. And quick too. It was pumping oil in there quick.

 

[SEABEE08FX4]

Along with the cam position sensor, bad batteries will do that too.

 

[Andrew]

Low voltage number 1 killer of all electrical. If you monitor battery voltage does it stay above 10v while cranking? If the sync pid toggles while it's running one of the sensors or wiring to it is bad. It could be as simple as the sensor having some rust build up between it and the block causing it to be too far away to get the proper reading.

 

[6speedsd]

Batteries are good. However, he did have a bad one a few months ago. Luckily it Didnt kill the ficm. If I EVER get time, I'll pull the cam sensor and make sure it's clean. Daylight to dark every day doesn't leave much time to troubleshoot, especially when that truck is on the road every day.

 

[Lassie]

I'll have to put AE back on it and see what happens. Honestly can't remember what it did last time.

Another thing is the oil gauge on the cluster doesn't come up either. I've always heard if it doesn't you have a lpop issue. I pulled the filter the other day and checked there while cranking and it started filling as soon as you start turning it over. And quick too. It was pumping oil in there quick.

These oil pressure switches do fail on occasion. Inspect the valley for oil. The LPO switch will leak through its guts like an ICP on occasion.

 

[6speedsd]

These oil pressure switches do fail on occasion. Inspect the valley for oil. The LPO switch will leak through its guts like an ICP on occasion.

Funny you should mention that. The valley of his is full of oil. He has a leak I haven't been able to track down yet. Has ran down the front of the motor and back side of the passenger head down on the starter.