Mechanics

04 MISFIRE

2004 Mercury Monterey • 190,000 miles

Having misfire problems with 3rd cylinder, I got code p0303 and another code that said problem before 1st 1000 revs.
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J.stieg
June 24, 2011.



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


Rasmataz
Jun 24, 2011.
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.


Tiny
J.stieg
Jun 24, 2011.
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


Tiny
CJ MEDEVAC
Jun 25, 2011.
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


Rasmataz
Jun 25, 2011.
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.


Tiny
J.stieg
Jun 25, 2011.
Dunno yet-till you check it


Rasmataz
Jun 25, 2011.
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?


Tiny
J.stieg
Jun 27, 2011.
Inspect and test the camshaft and crankshaft position sensor


Rasmataz
Jun 27, 2011.
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.


Tiny
J.stieg
Jun 27, 2011.
See below


Rasmataz
Jun 28, 2011.
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