PowerBoost rough charging idle.

[AutonomousHybridF150]

Ok, so my truck finally did something that I feel is caused by low compression on 1 of the cylinders.

I have a 99 mustang GT with Vortech V2 SQ, which high boost caused a cracked ring ledge (twice) in the OEM Hybereurtectic pistons.

In the beginning each time the issue was only noticeable in 5th gear at 600 RPM during WOT, and then went away by 1800-1900 RPM WOT. Compression during start up was 30-40 LBS lower than the other 7 cylinders, but the faster the engine RPM, the less noticeable the missfire was.

On cold crank the piston blow by was greatly increased, and so sometimes the engine would stumble on crank up and get stuck in a situation where it almost died for 10-15 seconds. Or until the accelerator was pressed to rev the engine up.

My powerboost had only set for 15 minutes while I was in Walmart. Upon cranking the truck the engine fired up and then it got stuck in that same stumble loop from 500 RPM to 800 RPM.

I videoed the gauge cluster showing the repeated stumble. I really think this issue goes hand in hand with the rough idle RPM when charging.

Has anyone experienced their Powerboost fall on its face shortly after crank up on a warm engine?

This almost cranked like a -30 degree cold engine with 150k miles on it.

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[PeteRit]

Wow, that's definitely NEW for 2021
And it's a great idea, but it's so strange that Ford would think you should know when it's 226 but you don't at 225.
Limp mode is supposedly ~250-254 on the 2017 - 2020.

My 15 Lariat 5.0 would pop up at 225 and then would go away when it hit 215. I live in Colorado and when I pull my SXS and ATV's over two specific my passes it would worry me every time. Surprisingly my 21 Powerboost doesn't even get warm over the passes here!

 

[F-150 Prius]

Yea, Ford calls what we always considered an alternator, a "starter generator". And they are right because it IS a generator and a starter in one! (I hate to think what that thing might cost out of warranty) And it is NOT an alternator because we don't need one. Which is fascinating as well.

Oddly enough, we still have a traditional starter, but according to Ford there is only one circumstance out of the listed 4 engine starting circumstances, that the traditional starter/flywheel combo is used. Basically it is for remote start.

I'm still not sure why that couldn't be done with the belt driven starter-generator, but I'm sure there's a good reason that I'm just missing.

So the Hybrid has a flywheel ring gear starter motor, a flywheel traction motor in front of the transmission and it has a belt starter?
This brought to you by the Department of Redundancy Department.

p.s. where can I find those parts schematics? : )

 

[F-150 Prius]

It looks to be pretty well buried in the engine compartment too, so who knows what the labor cost is. Maybe just enough to wipe out all your savings on fuel!

Where'd you get those schematics and prices … I'm curious to see what the battery costs as a part.
Thanks,

 

[F-150 Prius]

Also, btw, if rough idle is a problem (mine purrs like a lion) as a short term workaround, perhaps try to the "eco idle" mode … this significantly raises rpm to charge the battery as quickly as possible to have the engine shut off as soon as possible … it could result in a smoother idle … it's noisier (more exhaust noise) but it is smooth as.

 

[Pedaldude]

Where'd you get those schematics and prices … I'm curious to see what the battery costs as a part.
Thanks,

Parts.Ford.Com

You can search with or without a VIN and it looks like they're still slowly working on 2021 parts/descriptions.



There's also this site too:

https://www.etis.ford.com/vehicleRegSelector.do


I believe the graphic in post #16 is from a shop manual.

 

[Snakebitten]

So the Hybrid has a flywheel ring gear starter motor, a flywheel traction motor in front of the transmission and it has a belt starter?
This brought to you by the Department of Redundancy Department.

p.s. where can I find those parts schematics? : )

It's CrAZy, ain't it?
There's 3 different sources for spinning the crankshaft to fire up the ICE.

So when it does start, you really can't tell from the cab. But I don't know if I have EVER heard a traditional flywheel/starter cranking event. If I have it started so fast that I wouldn't be able to tell the difference.

 

[F-150 Prius]

It's CrAZy, ain't it?
There's 3 different sources for spinning the crankshaft to fire up the ICE.

So when it does start, you really can't tell from the cab. But I don't know if I have EVER heard a traditional flywheel/starter cranking event. If I have it started so fast that I wouldn't be able to tell the difference.

Same here. I would have lost a sizable bet if someone wagered me the F-150 Hybrid has a separate flywheel starter motor … I still can't quite believe it … there's a 7.5 kW high torque motor in the bell housing … ?! … maybe there's an electric clutch in-between so the engine can idle … I can think of some complications, but they all get resolved by "flywheel motor" and having the ancillaries powered by the traction battery … no need for a 12V other than as a conventional power source (for jumping and accessories) and a cheaper way than a step down transformer.
Imagine the wasted cost of developing a flywheel in-line motor (as already on the Aviator … I wonder if it has three starter motor scenarios) and then keeping the redundant ring gear and the weight of the flywheel and then developing a belt-driven starter generator?!
I can see how the in-line traction motor is a poor generator but that's only a problem if you insist on a 1.5kWh battery instead of a 10+ kWh battery …

 

[Snakebitten]

I have documentation regarding the electric motor and how it has its own clutch and how various scenarios have it participating.
But it's the belt drive "Generator/starter" that is most interesting to me since what is it that it does differently in regards to spinning the crank via belt VS the hybrid motor spinning the crank via clutch?
I've read it all a few times and still can't clearly get the picture.

And there is no alternator in the traditional sense. The 12 volt battery is kept charged by the Hybrid battery power.

 

[xtraman122]

I have eco idle enabled snd mine does this all the time as well. My wife was asking “why is it doing that, why are we shaking, is your new truck broken already??” The other day when we were sitting in some traffic snd the engine kicked on to charge the battery. I guess I always just figured it was normal and is rough because it’s actually doing some work charging up the battery running the generator. It feels the same it does when pro power is being used enough to require the engine to kick on.

 

[Harlemox]

I have had Eco Idle enabled on mine for a while now, but mine still stumbles when sitting at lights/etc. in drive.

Eco Idle certainly helps when the truck is in park to prevent the stumble though.

 

[AutonomousHybridF150]

Also, btw, if rough idle is a problem (mine purrs like a lion) as a short term workaround, perhaps try to the "eco idle" mode … this significantly raises rpm to charge the battery as quickly as possible to have the engine shut off as soon as possible … it could result in a smoother idle … it's noisier (more exhaust noise) but it is smooth as.

Mine goes from purring so quietly in generator mode at 1000 RPM to stumbling. Probably the MIL has something to do with it. Lol

 

[AutonomousHybridF150]

I have had Eco Idle enabled on mine for a while now, but mine still stumbles when sitting at lights/etc. in drive.

Eco Idle certainly helps when the truck is in park to prevent the stumble though.

Yours sounds worse than mine is.

 

[AutonomousHybridF150]

And there is no alternator in the traditional sense. The 12 volt battery is kept charged by the Hybrid battery power.

I read somewhere that they reengineered the entire body system at 24 volts, so they likely used smaller wires everywhere for weight / cost savings, and then probably used all that 24v re-work in the lightning. But, the point was, the 12v battery is in fact separate from everything else in the truck.

At least now all you have to worry about is your battery going bad. No more leaving your lights on or your inverter plugged in all night, and wake up with a dead battery. Plus the dead battery issue should be reduced by the lower engine compartment temps caused by the hybrid system while sitting idle.

 

[Harlemox]

Yours sounds worse than mine is.

I should probably also tack on that it only stumbles when the engine is not up to operating temp. When the engine is warm, I don't get any stumbling.

To be honest, most direct injected vehicles I've driven have a sort of "rough idle" very similar to mine. I don't really mind it as long as it's not damaging anything, and I figure if there is a problem enough people will complain to Ford about it for either a TSB or FSA to be issued.

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