04 monterey misfire

P0303: Check the no.3 cylinder's -sparkplug, compression and injector-let me know

I swapped spark plug and wire from cylinder 2 and put them on 3 and problem still came back to cylinder 3. I checked compression on cylinder 3 and it was over 100psi in first stroke and 150 in next and so on up to 200psi with engine off and just cranking with throttle open.

Coil packs on all plugs?

Swap it to another, see if misfire changes cylinders.

Recently had same similar issue with Wifey's '03 Escape---I do not know your rig, but I hope you do not have to disassemble the engine, as I did, just to get to the back 3 plugs!

This has been a commercial break, from CJ MEDEVAC

Continue to follow RAZ'S instructions....these new things kill me!

The Medic

Medic, if its COP it doesn't have S/P wire -DIS or TFI Ignition system?? You got a lot of car problems hang in there -I'm also responding to your New Yorker

200 psi-lil too muchy-could be a carboned-up cylindercausing it to raise. Have you check the injector-try checking its solenoid resistances and spray pattern/PWM

Ok, I will check "injector coil" resistance and compare with other injector,

do you think the misfire on cly3 is spark or fuel injector related?
Note: problem seems to be more repetitive and less intermittent now than a few weeks ago.

Dunno yet-till you check it

I checked injector resistance and they all seemed to be around 12.4 Ohms including #3.
I also checked injector spray on #3 and it came out as an even cone pattern. I tested injector spray by supplying voltage to the injector. where do I go from here?

Inspect and test the camshaft and crankshaft position sensor

I am ready to do that, I'v tested sensors like that before. I think They all have three wires. can you give diagram, and while I rotate engine what wires should I be checking for.

question: will a bad crank sensor repeatedly trigger the #3 cylinder misfire? I reset dtc's three times back to back before working on engine.

See below

each of the sensors have two wires. I checked the resistance on the crank sensor, and while rotating I got ohms from 1250 ohms to 130 ohms. At all positions not moving I got 642 ohms.

for cam sensor it was at 591ohms not moving, and 830ohms high side and 450ohms on low side

Not too sure -I don't have the specs for it-Have you check the sparkplug wire resistances on no.3 if not do so-

when I started diagnosing the problem I swapped the plug and wire from cyl#2 and put on cyl#3, and #3 to #2. Code always came back to cyl#3 repetitive.

whats causing the cly#3 to set?

Test the coil resistances primary and secondary windings for no.3

I think it could be the waste system. do you have diagram? thanks

I checked the three places for primary resistance all being consistant at 1 ohm. secondary seemed infinite on all. I look closely at #3 coil tower for cracks, din't see any.

Here are some readings I got from plug wires in ohms.

cylinder# 1 2 3 4 5 6
plug wire length inches 22 14 14 40 38 42
resistance in ohms 7.1k 4.5k 4.2k 11.7k 11.8k 13.5k

Try swapping injector for no.3 and see if i moves-

yes I swapped it around. Have not tried it yet because upper manifold is so hard to remove just tring to get every thing done before it goes back on.
I also checked wires pcm to injectors and pcm to ign coil. All wires are fine with no opens and ohms at .5, I will see how injector swap goes and post results.

put it all back together and It still says misfire on cylinder #3
Do you know if a bad crank sensor would set off a code for just cyl #3 ?

Hard to say what's causing the no.3 to misfire I know you're doing your best. Shoot it in the dark replace the CPS don't work have the computer reflashed

that's just what I did I bought a cps and I'm going to install it now. was a cheap one with 2 year warrenty at $20

I put in a CPS and cyl #3 still misfires.
If PCM randomly fails to send a ground pulse to the coil then cyl #6 should show up as a misfire as well, right?
It's pointing to the PCM, but not shure.
I'm going to try some other stuff.
Let me know if you have any ideas. thanks

I found the problem, It was the intake manifold runner linkage. It came off so I bought a clip and put it back on. I feel more power and no shakes, check engine light is off and not blinking.
I found it by accident when I was checking for plugged EGR passages.
Not shure why it was specifically setting cylinder #3
Runs good now.

Glad you got it running you came a long way-Good Job