[xceleratemaro]

2002 3.0 DOHC VIN S......

CAR HISTORY.... car has new e3 spark plugs and new motorcraft wire's

p0303 cyl missfire
and missfire at startup code.

cyl 3 missfire, cyl 3 located at the rear at the transmission side

pulled intake and checked wire and plugs agin swap wires at coil reinstalled intake and ran cleared codes ran diag still cyl 3 miss removed intake and swaped plug and wire with #1 and #3 cyl reinstalled cleared codes and rand diag still #3 missfire removed intake and installed new coil from store reinstalled and ran diag still missfire #3 removed intake and removed injectors #3 and #6 swaped resealed reinstalled, ran diag still #3 missfire pulled intake and #3 plug ran car sound like good compression, and put plug in wire and ground good spark on #3cyl.,,, removed valve cover and inspected valve's and spring cam's all looked good. reinstalled all compoents and still #3 missfire

i will paypal 5 dollar's to anyone that get me a solution without just replacing parts

im thinking it could be the inj driver on #3 is bad i dont know how to test for that thought,

thank you for your help

 

[Dubeckyj]

im thinking it could be the inj driver on #3 is bad i dont know how to test for that thought,

Same as plugs & wires. Swap injectors between two cylinders and see what happens. Also, look at the tip of the spark plug you took out of there before you put the E3's in... it could give you some hints as to the underlying problem.

 

[the_intimidator_02]

#3 plug ran car sound like good compression

Did you use a compression gauge and see what the compression was compared to the rest of the cylinders. By how you worded it in your post it sounds like you didn't. The only thing I can think of trying other then a compression test with the gauge is a cylinder leak down test to determine if the valves are sealing properly. But for that you will need a source of constant air and the adapters to hook it to the cylinder.

 

[BigPip]

Did you use a compression gauge and see what the compression was compared to the rest of the cylinders. By how you worded it in your post it sounds like you didn't. The only thing I can think of trying other then a compression test with the gauge is a cylinder leak down test to determine if the valves are sealing properly. But for that you will need a source of constant air and the adapters to hook it to the cylinder.

I agree with actually doing the compression test on the engine to see if there is a variance between the cyl.

Good Luck! I chased a P0303 on a Dodge Ram I had for 3 years. I have done everything you have done and I still couldn't shake it. the only thing I didn't do was a compression test which I should have done since the oil pump drive shaft was shot and didn't run all the time. Good think i fixed that before the motor went...

 

[xceleratemaro]

removed intake and installed noid light on inj harness #3 cyl is pulseing the inj so the emc is good...

when to the store and bought a compression tester tried to use and the adapter would not start in plug hole removed front plug to see what was up and the brass adapter got stuck in hole i have to get it removed b4 i go any further,, im thinking broke piston ring at this time i was able to use one of the adapters befor messing up the front bank.. but it is the style adapter where i has a rubber cone and when it was compressing i found that it would push the guage up no matter how hard you held it down so not a good reading it was 50 lbs

 

[maxin76]

try swapping injectors that the same code i got for a bad injector and it was killing me to get it running right

 

[sable23]

sounds like you need to do a leakdown test. because you have ruled out any other problem other than internal damage. a leakdown test will help pinpoint exactly what is damaged.

 

[xceleratemaro]

try swapping injectors that the same code i got for a bad injector and it was killing me to get it running right

i have all ready done that thank you chris no change

 

[xceleratemaro]

Compression test done #3 cyl 120 #4cyl 120 #5 cyl 120 compression is good

im getting desperate please help

 

[KhanTyranitar]

K, if you compression is good and the ignition is good, you my friend have a bad fuel injector.

Replace all 6 with new or rebuilt flow matched injectors. I made the mistake of replacing just one injector on my Aerostar, now it idles rough and lost 3 mpg. Now I have to do it again.

 

[loudsho92]

Was the misfire before or after the new plugs and wires?

 

[xceleratemaro]

sorry i havent been on here in a wile the missfire was after the new plugs and wires 2 weeks .... ran good for 2 weeks...

found the problem tonight 1 bad "new" E3 spark plug it would fire when out of the hole but when in the hole it would ark on the head..lol sob......5.99 fix it after a long week of diagnostic thanks for your help Chris

 

[KhanTyranitar]

You are running E3 plugs, must have missed that. Take them out and replace them with a set of Autolite double platinum. E3s are low bidder oriental junk that does not live up to the claims.

 

[loudsho92]

sorry i havent been on here in a wile the missfire was after the new plugs and wires 2 weeks .... ran good for 2 weeks...

found the problem tonight 1 bad "new" E3 spark plug it would fire when out of the hole but when in the hole it would ark on the head..lol sob......5.99 fix it after a long week of diagnostic thanks for your help Chris

That is where I was about to go. Glad you found it.