Misfire without code?

[JohnnyBGood]

My 2004 5.4 with 166k miles has what I guess is a misfire.

I can make it happen almost every time by going about 45 mph, letting off the gas, then slowly accelerate. The truck "shutters"

So that's a misfire right?

My question is I see this described in other posts but almost always with a engine code that describes which cylinder. Mine has no check engine light currently. So do I have a misfire?

My plan was to replace the plugs but my mechanic quoted something like $300 so I said I would do it myself when I get the time. He suggested an induction cleaning and if anything that made it worse.

??

 

[bedrck46]

does your check engine light come on when you put the key in and just turn it to the on position without starting the engine??

 

[JohnnyBGood]

does your check engine light come on when you put the key in and just turn it to the on position without starting the engine??

Ah, good question. Yes it does.

 

[bedrck46]

from you description it doesn't sound like a misfire but I could be wrong sounds more like a problem with fuel and air
When were the plugs and coils last changed? Have you checked for any vacuum leaks? When was the fuel filter last changed? Also what is the condition of the exhaust ports thru the throttle body?

 

[JohnnyBGood]

from you description it doesn't sound like a misfire but I could be wrong sounds more like a problem with fuel and air
When were the plugs and coils last changed? Have you checked for any vacuum leaks? When was the fuel filter last changed? Also what is the condition of the exhaust ports thru the throttle body?

I know the answers to none of those questions. other than have you checked for vacuum leaks which I have not. I just bought the truck.

In regards to this problem the only thing that has been done is an "induction cleaning"

 

[bedrck46]

also when was the last time the air filter was changed

 

[bedrck46]

when the "induction cleaning" was done was the throttle body removed or was it done with the throttle body in place??

 

[toms89]

One possibility is torque converter shudder.

 

[JohnnyBGood]

One possibility is torque converter shudder.

I don't know if I am describing the problem accurately. It feels like a sudden sharp loss of power that returns quickly. that repeats for 100-200 rpms. then cannot feel it at all. Engine is strong in all other rpms. Only happens when I a rolling down road at about 40 mph.. let of gas.. then re apply gas.

 

[toms89]

I don't know if I am describing the problem accurately. It feels like a sudden sharp loss of power that returns quickly. that repeats for 100-200 rpms. then cannot feel it at all. Engine is strong in all other rpms. Only happens when I a rolling down road at about 40 mph.. let of gas.. then re apply gas.

Hesitation??

 

[toms89]

You should post video as it occurs with the gauges in view. Could possibly help others to understand your issue better.

 

[JohnnyBGood]

You should post video as it occurs with the gauges in view. Could possibly help others to understand your issue better.

Ok Ill try.

Hesitation, sure sounds right.