Hey, just trying to figure something out:

Recently bought a 99 Stratus ES with the Mitsu 2.5 V6

Just replaced the crank position sensor but the engine is still [sometimes] hard to start, started yesterday but died almost immediately, and then other times will start without an issue and drive perfectly.

Tried to get some codes out of it last night, got nothing. Plugged it in before work this morning, got P0300, P0301, P0303, P0305

So clearly the back 3 cylinders are having problems. The plugs and wires have less than 10k on them so I don't think it's that. I'm hoping it's just a distributor cap & rotor but what else am I looking at here?

 

It could be injectors, bad valve cover seal, poor compression in that cylinder. I would first pull the plug out and see if there is any oil in the plug tube. If thats the problem it's rather easy, and inexpensive to fix. If it's nice and dry (oil wise) than that's another issue.

Eliminate the easy things and see what goes. Keep us posted and I'm sure we'll come up with more things to look at as you eliminate possibilities.

 

Would it really throw the code for all three cylinders, though? I could see the injector rail going bad back there...that would make more sense but then wouldn't I get some more driveability issues? It doesn't run poorly...seems fine once it's started up.

So far the only thing that was weird was when the engine was cold it would idle way up to 1,100 and then fall out to almost 400 then back up to 1,100 and repeat. It was only every so often and I figured it was tied into that crank sensor.