p0303 Misfire- absolutely shocked

860

Asked by Timothy Oct 21, 2014 at 10:07 AM about the Dodge RAM 1500

Question type: General

I own a 116,000 mile Dodge Ram Laramie 1500 5.9  thats driving me nuts.
Bought the truck in Connecticut and drove it home thinking it just needed a tune up. The truck sat for almost 6 years in a heated climate control garage. It is in excellent shape but it sat for a while, so I went right through it with the following.

ALL OEM replacement parts
New cap rotor and distributor ( tapped out too much and effected the cam sensor movement)
new plugs, wires, all new fuel injectors (8) in total.
New evap canister valve.
New ignition control sensor and CKP sensor
New Collant temp sensor
New throttle body with all new sensors, MAF, IAC and Throttle sensor
New radiator, water pump and all new lines
Put it on my buddies Modis computer and timed new distributor to top dead center 0.
Was running rich, ( leaky injector) fixed and replaced.
Now that all this work was done, it now randomly throws a p0303 code on bank 1.
Tested the fuel pressure ( 49 PSi) right on the money and even at higher RPM's dead on.
Did a compression check, all was perfect no issues.
Are their any wiring issues on these trucks? Could it be an electrical thing? Is there a place where they come together in the back behind the distributor? or do I have to chase the the fuse box or PCM?

I need some help on this one, I am stumped. The only thing I can think of is it has to be electrical.
Any help would be greatly appreciated.

2 Answers

143,755

Compression check will not show a scorched valve,this will give you the misfire,and is hard to diagnose,the only reason i say this,my 99 silverado did it,and beat my head in ,spent lot,s of money,and still had the skip,story sound famiular?Remove the head,on the side of the number 3 cyclinder,you will more than likely find this issue.

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