I know I'm beating a dead horse, and you've all heard this question a thousand times but....here's the thing. I've got a 2002 f150 supercrew 5.4 w/ 80k miles, it started missing on acceleration about a month ago. So I replaced the plugs w/
iridium bosch from napa, and still had the problem. So I took it to my local Ford dealer, paid $70 dollars to have them tell me "no codes were found". But they recommended a tranny flush. Well, I'm a motorcycle technician by trade and I know the difference between a tranny problem and a misfire, atleast I think..lol.
So I bought one COP and replaced it on every cylinder to see if it repaired the misfire, but no. While I had them off I cleaned, regreased and checked the boots, they were fine.I checked the MAF and it looks clean. I'm startin to get worried here..Any ideas? And yes I washed the motor before this all happened but I havent found any moisture anywhere.

 

Have you had this truck on a scanner yet ? looking for misfires /cylinder .
Cheap scanners won't do it you need a good one.
If it is indeed a misfire.
What about injectors,fuel filter,fuel pressure.Knock sensor.
My personal opinion get rid of the bosch plugs,there have been problems in the past with them.

 

Yeah, I took it to my local ford dealer and they scanned it. They said there were no codes. So they took it for a spin and one of there younger techs said it felt like the tranny. Trust me, It's not the tranny. It hesitates on accel. at any speed and wether overdrive is on or off. Wether or not its an injector I dont know. It just seemed to act like plug wires, but since there are no wires I figured the cop was the best bet. Im gonna try cleaning the MAF sensor tomorrow and see where that gets me. I'd get different plugs but those cost me an arm and a leg. I'd hate to junk em' for nothing. Whats the easiest way to check the fuel injectors? And wouldnt they throw a code if they were not functioning correctly? Thanks..

 

Junk the Iridium plugs and put Motorcraft or Autolite double platiums back in it. These COP ignition systems don't seem to like anything but the Double platium plugs. Something to do with not having a plug wire to act as buffer between the coil and plug.

 

Well so far here's where I am. I popped the ses light yesterday and had it scanned this morning. # 3 cylinder misfire. So I installed a coil I had from my last replacement efforts. I changed the plugs to motorcraft, changed all the boots on all coils, new fuel filter, checked fuel psi= 30 at idle, w/ throttle applied it jumps up then goes back just under 29 psi. I checked the pcv valve and cleaned the MAF. I drove it tonight, still hesitating. Man, Im losing my mind. It wont pop the ses light again and I checked it on the scanner and no codes were found. And yes it was a good scanner. Any ideas would greatly be appreciated. Can an injector set off a cylinder misfire code?

 

I have had a similar problem for at least 30000 miles! And yes, I'm tired of it. I have had it to the "mechanic" for scans twice (NO CODES). I've been told to run it until it "throws a code". One thing I've noticed is that if you "turn off" the overdrive, the problem seems to go away. This made me suspect the torque converter or at the very least the tranny. It just hesitates when it gets a little bit of load on it and needs more fuel or a "shift". Mine is a '02 S'crew w/5.4L and 93000 miles. Still no codes and still hesitates

 

Its not always easy to find problems.If it is a misfire,it will not post a code until the built in threshold within the pcm is reached.But dealers techs,most don't go far enough into diagnostics to find them,They take the easy way out because they get paid by the number cars through the shop. Spending a long time on one vehicle doesn't pay them.
Have you run any injector cleaner through the system?
A bad injector will only throw a code if it goes open circuit electrically back to the pcm.It could stick open or be dirty causing a rich condition which eventually cause a lean slightly because the 02 sensors will tell the pcm to adjust fuel trims.
Have you done a plug read are all plugs the same color when looking at them?
Also basic engine health(compression test ) would be in order hear also.



We have seen transmisions have torque converter problems,and no one would say it couldn't be a problem.Its a different type of hesitation though.
Have the tranny serviced it may be the problem.
Rich

 

I was thinking tranny, but when it does it w/ overdrive on or off, it just seems worse in Overdrive because the of the rpm and oad being put on the motor.Im gonna try injector cleaner, unfortunatley Im leaving to go on a hunting trip tonight and I need the truck so I cant do much more until I get back.I'll keep you guys posted.Thanks for the replies. Oh, and would a egr valve cause a similar problem?

 

Maybe a good road trip will help clear things out. Floorboard it a few times to load the engine and raise the fuel pressure, this may help too.

 

Well, I put about 500 miles on this past weekend. It's still doing it. I noticed from 45 to 60 mph in high gear just under load, small hills etc. However the engine light wouldnt come on. So I guess I'll just wait till it does.

 

I have a cousin with a 4.6 when he floors it at deadstop-30mph itll hesitate for about 5secs kinda like if he would have added a stalled rpm torque converter but the rpm's dosnt raise when he nails it

 

Ernie ,did your cousin chk his fuel pressure at the rail at Idle and at part throttle ?
Then clean the maf ,iac chk the plugs looking for different looking ones (firing patterns ,color)

I got your msg,what was your ?
Rich

 

Well, its been over a 1000 miles and its getting worse. Still no SES light. I'm just gonna break down and take it into the shop. It now hesitates during accellaration in all gears, all speeds and sometimes at idle, so that rules out tranny. How hard is it to clean the egr, and could it cause these symptoms?

 

Well my SES light finally came on again. This time #7 misfire. I'm gonna pick up a new coil and try it again. Any ideas on where to buy. I can get them for around $30.00 a piece, thru a catalog I have. Or on Ebay for 120.00 for 8. Are these any good or has anyone tried these c.o.p.'s. I know I can get better ones for around $70.00 from Napa but I'd hate to spend the money if I dont have to. Thanks again.

 

They are all made by Visteon, just packaged different. Any aftermarket should be fine.