Got off work at 430am this morning and truck back to missing slightly.

I am stumped!!

Each time its ran bad ive pulled plugs and coils and its ran better.

Mechanics cannot find a misfire at all on the obc while troubleshooting, but can physically hear it.

This is stressing me out.

 

Please describe said misfire...

Does it sound like a diesel, or muffled marbles in a can rattling type sound?

Does it do it under 1/4-1/2 throttle but go away at full throttle?

I have tuned many cars and that's why I need to know this information to help diagnose the issue.

Coolant temp gauge is showing correct at around 1/2 way?

The reason why I ask is because my truck was not throwing any codes, no misfire counters etc... It turned out to be my MAF.

If your taking it to a shop ask them to plug in their snap on code reader and monitor IAT temps, short term fuel trims and long term fuel trims....

If they get on the go pedal and you see negative values in either the short term or long term trims, your MAF is toast or you have a vacuum leak somewhere.


My money is still on the MAF as you said in your first post that you sprayed it down with carb cleaner.... Almost guarantee you killed it.

Call up Jean at tousley ford. It's only gonna set you back like $130+core.

 

It sounds like the engine is flooding when i hit the pedal....it just sounds like its bogging down.

Its worst around 40-50mph when overdrive kicks it and between 1k-1500k rpms.


Like i mentioned earlier, its intermittent. Ran a little better this evening.

Its not missing much in idle, but more when theres a load.

 

Ok, just drove home and here's what i have to report.

The sound is more of a sputtering sound. At idle, it does sputter and hesitate a little bit and when it does you can feel in the cab.

While driving, if i ease into the throttle it minimizes the sputtering /hesitation and lack of power. If i get into the throttle, it sputters/hesitates real bad and doesnt have much power, regardless of speed and rpm's.

I unplugged the maf sensor and no change.

Im baffled. Ive pulled the plugs twice. Each time, i cleaned, reinstalled, and it drove very well for several days.

Then it goes to ****....

Still no codes.

Why would pulling the plugs make it run for a few days?

Im just about to drive it to a shop and have them fix.

Frustrated!


This is my vent for the day, thanks for listening

 

Did you rule out the "fuel pump" by testing it while engine is acting up?

 

Here is my recommendation....

I am fighting the same battle now. I replaced a bunch of crap, even had my ECU flashed at the FORD dealer today and now having the same issue you are....

I 100% think if you unplugged your MAF and still idling like crap and feels lumpy, its gotta be a bad COP, or a few...

I know you just replaced your COPS, but I bet you have a few that are garbage. You really need an oscilloscope or pull the cops and use an ohm meter and find the value. Each COP should be the same value, if you have one that's different then that COP is bad.

I don't recommend this, but I had no other way to track it down.... I removed the vacuum hose from the Fuel Pressure Regulator and capped it off and then I was able to find misfire codes on cylinder 3 and 9. In doing so it created a dead miss and makes my truck run way worse, but at least I know what cylinders to track down. I bought 10 arapart COPS tonight and I will be using FORD COPS to replace cylinders 3 and 9 tomorrow. removing the vacuum line bumped my Fuel pressure up from 30 to 40. It could cause more issues, so again I do not recommend this, but this did help me track down my cylinders with issues.

 

Typically testing COP's with an ohm meter doesn't really tell us much. Known bad COP's can pass the factory spec's. If an occiliscope or similar automotive-type computer diagnosis unit is available a more through test might better reveal how the COP's are acting when in actual use.

 

You need a scanner that reads code 6 misfire data. I use this one. It is cheap and it works. I know it works with the iPhone app; not sure about android.

 

My 04 misses every now and then. It will miss and go away and then miss and go away but it will do it for only 1 day then truck will run fine for 2 mounths then start doing it again. What is causing this I have no idea.

 

Ok,

I have not had any time to dig in again but I am now pulling up a stored code which is a #5 misfire code. Had to be my luck to be that one lol.

 

Checked all connections to cop's and injectors. All are tight.

I am now showing p0300 and p305 as codes. New plugs and new coils with not even 250 miles on them....what the hell?

 

I'm not to sure what to do from here.

Let me run back by everything I've done in order.

Bought truck about 6 weeks ago.


-Had engine flush done (oil looked terrible)
-had oil changed, 5w20 penzoil
-Front and rear differentials changed
-torque converter fluid changed
-replaced fuel filter with a cheap one from autozone
-ran seafoam in fuel tank
-ran seafoam in brake booster line
-pulled old plugs, looked ok so I cleaned and reinstalled
-clean throttle body and MAF with carb cleaner....whoops...
-tried more seafoam, lucas, Techron fuel additives.
-Pulled plugs, replaced with MC gapped at .054
-cleaned throttle body again
-replaced pcv
-tried disconnecting MAF
-pulled plugs again, installed again
-installed all new COPS
-checked all connections to cop's and

Each time I have pulled the plugs and reinstalled the truck ran good for 1 day and 1 day only, then back to missing.

Was not getting any codes until recently. P0300 and p0305.

The 1st time I pulled plugs I must have accidentally pulled off the engine ground strap the connects to stud on passenger firewall. Didnt have alot of hardware so it's not 100% tight. I checked it last night and I can wiggle it around. Im grabbing some hardware tonight to get that tightened up. I've heard grounding issues can cause misfires.

I'm open to suggestions guys, at a loss. Truck ran fine when I bought and now it's running terrible.

thank you all for the replies.

 

P0300 means a generic misfire. IE: Can't determine which cylinder is misfiring.

P0305 means cylinder 5 is misfiring.

With the truck running put your hand on the valve cover, pull the ignition coil plug wire and see if the truck stumbles. "IT SHOULD". If it doesn't it means either A)COP is bad B)Injector is bad.

I would also invest in either a noid light kit or a test light....

If you haven't seen scanner danner on youtube, look him up. The guy is a true mechanic and knows his stuff. He can help you out how to determine misfires rather easy.

https://www.youtube.com/user/ScannerDanner

I would still suggest in purchasing a scanner... Helps you diagnose way more than you can without one. Plus they are CHEAP.

I am having the same issue right now... I just went head and bought all new COPS and new injectors so I have a good starting point. My time is not worth the $100 bill for new parts.

Here are the injectors I bought.

http://www.ebay.com/itm/3-Year-Warranty-F-250-Super-Duty-Excursion-GENUINE-BOSCH-Fuel-Injector-Set-/281051140414?pt=Motors_Car_Truck_Parts_Accessories&hash=item416ff4113e&vxp=mtr
Here is an example of him troubleshooting COPS.

 

What COP'S did you end up going with?

I am going to start w the engine ground strap and get that secured. Then move to the pcv hose and reinspect it. Then replace that autozone fuel filter with MC brand. Then I guess tear back into plugs and coils.

 

I bought 3 from Orielly and none made a difference, I also bought a complete set of ARAPARTS coils online. Should be here by Friday Hopefully.