idle/miss cylinder drop

[fishnstash]

Hello all,i could really use some help.2006 ranger sport3.0 v6. CEL came on miss fire #5,changed coil pack,better for a week then same again,replaced plugs,wires,coil pack again,pick up sensor,cleaned MAS,IAC,throtle body,added lucas fuel treatment,again better for a while,now back to very rough idle,if left to idle with or with out AC on it will eventually drop a few cylinders but no CEL,throw it in N & rev. sometimes it will clear out. top end runs fine, this happens hot or cold. I'm losing my mind and $$$$$$ please advise

 

[Rearanger]

I guess you checked for vacuum leaks?

 

[fishnstash]

yup,no vacuum leaks. 1st CEL code was miss fire #5 i changed coil pack,2nd CEL code was same changed the coil pack again.3rd CEL code was crank sensor replaced it every time i change something it gets better for a week or so and then back to a rough idle and droped cylinders at idle. when cold she idles at 1100rpm and when warm 750-800 but then will drop to 600 or fluctuate between 600 and 750 before dropping cylinders i was reading the archives about a DPFE sensor???? could removing the downstream catalytic converter have anything to do with it????

 

[Rearanger]

could removing the downstream catalytic converter have anything to do with it????

If it has/had a sensor that feeds info back to ECU, maybe. Why'd you remove it? I'd get the engine hot then do a compression check.

 

[fishnstash]

No nothing quite that stupid. i just separated the cat and knocked the guts out and put it back together but that was a long time ago.

 

[fishnstash]

I have been reading a lot on here today about the MASS AIRFLOW SENSOR so i unplugged mine after the truck was warm and the idle dropped for just a second then went to normal rough. but there was no significant change even when the throttle was raised and it threw no CEL could the MAS be bad?????????

 

[fordboi415]

goodluck, ive been chasing the same issue around for almost 2 months, 2 different mechanics, now currently at ford with almost 2k into it... when i find out what it is ill be sure to let you know

 

[fishnstash]

well after reading it on here DUHHHH ( K&N filter oil can get sucked up in the MAF sensor) i bought another can of MAF cleaner douched it out real good shes running a little better now, but something is still not quite right when shes good and warm & at an idle.

 

[fishnstash]

Help please

now a new development,back to the305 & 316 codes missfire#5 1st 1000 rev. and now stalls @ idle while on brake . please HELP

 

[Rearanger]

Do a hot compression test and let us know what you get. Other than that I'm thinking you are missing a vac leak.

 

[fishnstash]

ford technical bulletin 05-26-3 bad design on cylinder head valve seats.