Mechanics

ENGINE CODE P0303 MISFIRE #3 CYLINDER

2000 Dodge Dakota

Engine Mechanical problem
2000 Dodge Dakota 6 cyl Four Wheel Drive Automatic 155, 00 miles

I have been getting the engine code P0303 with the check engine light. When this first started I changed the spark plugs, plug wires, rotor and cap. The check engine light turned off. The truck ran fine. After a month or so the check engine light came on again, same code P0303. I changed all six injectors, check fuel rail pressure (all to spec.) And cleaned the throttle body along with the Idle air intake motor, and new throttle body gasket. After this the truck ran great, getting better milege with the injectors. After a month or so the engine light came on again, same code P0303. The only thing I can think of is to replace the coil, check the plugs again, and maybe replace the Air Mass Intake sensor. Would these help? Do you have any sugestions? Their isn't any sign of burning oil or coolant coming from the exhaust, its clean. I am all out of ideas Please help.
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Captainwisch
October 25, 2010.



Hi Captainwisch, Welcome to 2carpros and TY for the donation

P0303

This misfire is only affecting (1) cylinder which is no.3-Have you done a compression check on no.3 both wet and dry tests-let me know the results-could be a connection problem at the cap and plug end on it, injector seal not seated properly, -if its the coil it'll be affecting the other cylinders same goes to the EGR and MAF.

Lets start by checking the camshaft and crankshaft sensors-inspect and test these sensors it tells the computer which plug and injector to fire upon and report back with the end of results-we start here

Rasmataz
Oct 25, 2010.
Rasmataz,

Sorry it took a while to get back to you with the answers. I just did a wet/dry compression test on cylinder #3. The results dry were 80psi and wet was 100-120psi. All the other cylinders dry tested at 130-150psi. Does that mean the valves in #3 are bad? What should I do now.

Tiny
Captainwisch
Nov 23, 2010.
The problem is coming from the valves on no.3- reconfirm it with a cylinder leakage test-

Rasmataz
Nov 23, 2010.