His free flowing aftermarket exhaust system could be reducing the scavenging effect at low rpm, further increasing the 'rich' condition and causing the bog off the line.

 

ive got some of bills custom tunes... but any idea why it starts rough, only happens when its hot

 

I thought you just were running edge canned tunes.. Anyway, if it happens @ 90 F outside / I would data log , then fine tune to get the most out of your bolt ons. You running high octane fuel ? HO fuel takes longer to burn and heat adds to it...~ Timing has quite a stretch to catch up at this point, to the point you are running rich and not burning all the fuel completely = Power/Performance loss.

Dual exhaust (after the muffler) doesn't matter unless your running "True Duels". That eats up performance that can't get dialed back in. This only helps way up there in the RPMs and usually, you don't drive at those rpms - so , it doesn't help and can really do a world hurt to your torque. That's what noticed most in the seat/ get's confused w/power.

That's great , you have a tuner - Yea data log and send the sheets /or if the tuners close by - make a Dyno appointment. Those three valves fly when dialed in right

 

And, since you're running Bill's tunes, I'd ask him if he has any ideas. PHP is VERY interested in customer support, so get in touch with them. They're very busy right now, so it may take some time for them to get back to you, but I'm sure they will.

I have NO idea why it would start hard.

- Jack

 

Fuel used/IAT reading -warm start/tuning incorrect.

She'll perc right up once dialed in/ fine tuned - probably be a very noticeable improvement all around via a good tuner.

 

I was monitoring my guages and LiveWire PIDs the other day with the A/C on for the first time since I got it. The inlet air was 118f and the coolant went up to 202f. It has a 180f t-stat installed so I was curious to see what was happening. The power and response didn't seem to down even with the extra load. Needless to say I was surprised. Now the transition fuel is tuned a bit richer and the spark is set higher. It's better than a canned tune for sure.

 

Just a thought but, could this be my coils making problems?

 

I just chased down a bad COP(it wasn't totally bad just not putting out full power) and it was felt at all times. It was more pronounced off idle when the EGR kicked in while driving. It was explained to me that EGR leans out the mixture which calls for more voltage to fire the plugs and it already was having trouble at idle.

 

On a 1999 Ford F150 5.4L Anyone figure out the problem when in high temperatures (summertime only) the truck sputters chokes out and dies but then let sit for a while it fires back up but then does it again? But it runs like a champ in cooler temps! I'm trying to help my older uncle with his truck, I've read it can be the IAC we cleaned his but might just put another one. Just don't want to spend money on unnecessary parts. Thanks in advance! 🍻🥃

 

I have a 2004 lightning with the same problem and it only happens in Arizona in the summer when it hits 103 degrees and up. I have owned it since mile one and the first time I visited Arizona in the summer back in 2008 it happened and once in Sacramento. But now I retired in Arizona and I can't drive it in the summer at all. I'm writing you because no has a clue why this is happening and when I read your message it was nice to hear I am not the only one with this problem. All I can tell you is I have changed everything so far except the PCM and I am not ready to spend another 3 thousand with summer ending. Maybe next year if it fixes it I will let you know.
Sad to say that I am glad I am not the only one.