A little problem
 

Alright I have a 2006 fx4 5.4L with a gryphon running bills custom 87 performance tune.

So today I was driving to the lake maybe pulling about 1100lbs in the 87 performance tune and when I pulled into the gas station my truck started idling horrible. So I shifted to park and the same thing. Also with reverse and neutral. I thought maybe it was a fluke, so as I was leaving I went to get on it, to possible clear it up, but the truck felt like it would not get out of its on way. So I pulled over into the next gas station because the truck had not much power going down the road and felt like it was going to die at red light. I set the truck back to level 2 and it has all cleared up. No problem ideling or getting up to speed.

I also checked for codes and it came back with none.

At first I thought it could not be the tune since it didnt do it from the beginning, but now I am skeptical since changing the levels helped. Also I have no clue if this is in relation to the problem but the other day after having my truck sit for a while....maybe a week in the hot sun, when I cranked it up, the truck made a clunk? sound possible.

Any thoughts?

Oh and the rpms were steady while it was acting up.

Any precipitation going on?
Kind of sounds like my "mysterious miss" post.
Except that was stock with no tune.

Lars

nope no rain in the past 4 or 5 days. Very humid and about 95 degrees at the time. Yea it definitely has me stomped....specially since the rpms wasn't bouncing around although thats whats it felt like.

That's more than weird! How can you have such bad performance and not see it on the tach?

Except, I wonder if the timing was suddenly wrong? Possibly overadvanced? You'd think there'd be "ping" though, if that were the case. And, if it was suddenly retarded, you'd certainly lose power, but I doubt you'd get the other symptoms. Valve timing? And, no codes - really weird.

Wonder what happens if you go back to the performance tune?

- Jack

Yea I found it very strange not to see it on the tach. I did not hear any pinging whatsoever...had the radio and everything off so that I could listen good. You could kinda hear a pulsating in the exhaust tone. Also definitely no codes....checked a couple of times.

I thought about switching it back to the performance level and see how it would act, but I have been trying to log some time in the tow tune to see how it would act and make sure it was staying normal.