My accelerator got stuck under my floormat and revved pretty hard while i was trying to get it unstuck. Afterwards my jeep start driving rough and idling hard coming to a stop and while stopped. Just wondering if anyone has any ideas on fixes for a p0305 code. I cleared it then put new plugs, wires, rotor and cap on it. Still has a misfire in the 5th cylinder and throws the check engine light.

 

I might do a compression test on cyl 5.

 

Swap injector #5 with another one and see if it follows

 

Both of those pieces of advice are good ones.

Injector swap (verify connector/wiring) and a compression test.

 

Thanks, the compression test was next on the list. I'll check with the injectors after.

 

If the injector swap shows nothing and the compression check shows the compression is within spec, I would suggest you pull your valve cover and inspect the valve springs for #5. Bring #5 to TDC Compression. See if a spring is broken or seems to be very loose. You may also want to pull your pushrods for #5 and see if they are bent.

I take it that when you changed your plugs #5 didn't show any mechanical damage, or other fouling.

 

As you thought the plug for #5 was fine. Only had time to run compression tests on all cylinders. #5 was well below the rest at 90psi while all others were 150-160.

 

I think Ken has a good suggestion to check the valvetrain/pushrods.

 

If you can access the equipment, i.e., compressed air source (I think you can rent a small compressor from Home Depot or a Rent-All store) and a gauge/valve setup (which I think you can rent from an auto parts store), you may want to do a compression leak check on #5.

Position #5 at TDC compression so both valves are closed. Apply around 80 psi to the cylinder then listen for air escaping the TB (intake valve cracked, burned, or held open), air escaping out the exhaust pipe (exhaust valve problem, like the intake valve), or air escaping out the oil filler cap opening (bad rings or damaged piston).

With 80 psi applied, you should have no more than 25% leakage. For example:

 

How far did you overev the engine? If past redline you may have damaged the top end moving parts.