you could have an injector going out. do you have any way of looking at the short term fuel trims of the injectors?

 

No I'm not exactly sure what you mean? I have a race evolution. It threw a over boost code the other day but that's it. It still runs strong just has that miss its starting to make me nervous.


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The injectors in the 6.4 don't use engine oil like the 6.0 does if I'm not mistaken to fire do they? Thanks for the help.


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the only scanner i know of to check the fuel trim is the ids at a ford dealership. 6.4 is high pressure common rail. so no oil to fire the injectors.

 

do you hear a ticking noise when it is missing?

 

No ticking it just misses. Like its going to die for a split second and shakes the truck just a bit like you can hear and feel it. I thought maybe egr valve was stuck or sticking. I pulled that black plastic cover off the egr valve and was able to push the shaft down and it comes back up.


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Did you ever figure this out? I am new to this site. I have the same truck with same setup. I am also having the same problem. I am leaning toward bad egr valve. I was curious as to what you found wrong. Thanks in advance.

 

Never mind, mine was just a dirty MAF sensor, all better now. I knew I over oiled the air filter.

 

Ok I retract my previous statement. My problem continues, only at idle when the A/C cycles. If a/c is off it does not miss. Anyone have ideas? I realize this thread is really old and will start a new one if no response.

 

I had a similar issue. It appeared after I tuned it (Spartan 175HP) and disappeared when I did the full EGR delete, and update to 175 NEGR.

I just got my truck back after it was in the body shop for a few months. I'll watch for it over the next few days and see if I notice anything. Just to make sure before I send you on a wild goose chase.

 

it's usually an injector dropping out

if you watch the power balance on an IDS, every time the AC compressor kicks on, you'll see whichever injector that's firing at that moment drop out slightly. It's exaggerated when in drive with your foot on the brake.

If you have an injector with a weak solenoid, if it's firing when the AC cycles, it can really go into an erratic misfire until you rev it clean.

 

What causes this? How can I fix it? And yes it is a random injector whichever is supposed to be firing. Is it a problem with the a/c?

 

put 8 new injectors in it. you can start replacing the worst ones, but eventually you'll replace all 8. been down this road before

 

i've seen a/c compressors lock up and cause a runs rough/no start. pulling the belt off of a 6.4 to check is a bit arduous, as i think it pays almost 4 hours to remove belt.

sounds more like an injector going out. I usually accelerate hard uphill and see if the truck shakes/skips.

 

Could it be an a/c clutch relay problem or something? It's definitely not a specific injector, it's random which one miss fires 1-8.

 

I was just wondering about that this morning every 15 seconds i think. truck is idling then there is that stuter and it keeps going. I didnt think to turn the ac off though.. I only have 77k on my truck, could an injector be going out already? I race people on occasion but i dont beat on my truck. Also running diesel kleen, have opti lube coming by end of week will update if there is a change in idling.

 

Roll down your window and listen to the a/c compressor kick on and off causing the miss. Then turn a/c off and it stops. Usually as soon as you hit a/c to turn it on again you will hear the miss, then it will continue every 30 seconds until it is turned off again. I have not noticed any problems above idle, possibly a reduction in fuel milage.

 

My truck started when I tuned it. Either that or i didnt notice it before. Il try turning off the AC tomorrow.

 

This is exactly what I said and everyone breezed past it. Mine did too, Spartan 175. Went away when I did a full EGR delete and switched to NEGR tune +175. I paid attention today to make sure. Definitely gone.