My 5.4 suddenly started missing on 4 cylinders at once. Codes are P0351, P0352, P0353, & P0357

Coils were tested OK by dealer.
Crankshaft Position Sensor was replaced
PCM was reprogrammed by dealer
Nothing has fixed it yet.
These are the first 4 cylinders in the firing order

Anyone ever seen this or have any ideas for a fix

any help appreciated...

 

It kinda sounds like your timing chain may have skipped a link. When you say the first four do you mean #1-4 or the first four that fire?

 

The cylinders are 1, 2, 3, & 7

firing orders is 1, 7, 3, 2

this is 3 on one bank and 1 on the other bank probably can't be timing chain....

 

Do you have individual coil packs or just the two that run 4 cylinders each? If you just have the two then see if one of them controls those cylinders.

 

I will tell you exactly what the problem is.You have a vacumm leak,between the PCV and the Idle Control Valve.The rubber hose that connects to the Idle Control Valve has dried out, and has now melted. The valve is at the center back of the engine and is hard to get to.Check it out.

 

my engine has a coils for each cylinder

how can a leak at the PVC valve cause 4 different cylinders not to fire ??

cylinder 1, 2, 3, & 7 are not firing but they all have the battery on the red/green wire.

 

Shotime,

The misfire codes indicate just that; a misfire. It could be fuel related. Has the dealer looked at the injectors? BTW have them reimburse, if you paid, the crank sensor. They obviously misdiagnosed the problem.

Regards

Jean Marc Chartier

 

I replaced the Crankshaft position sensor before I took it to the dealer. It was an inexpensive part and guess work.

I think the dealer checked the injectors. Not sure. The OBD codes says mal****ioning primary or secondary coil. Dealer says the coils are not firing or getting trigger signal, they just do not know why. I'm trying to locate a Ford wiring diagram for it to see if the leads are close together where they go through the firewall to the PCM.

1997 Ford F250 XLT Supercab with 5.4