No power from a stop - keep getting stuck
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Cross-Country
Joined: Mar 2020
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No power from a stop - keep getting stuck
Note- I edited for increased clarity -
If I'm on a hill and I'm starting from a stop, if I give it wide open throttle, the van takes a very long time for the rpm of the engine to get high enough to shift into 2nd gear. If it's steep enough, it won't move at all, and the rpms don't climb. With engine tuning off and on level ground, it takes a long time for rpms to climb - but once I get to about 25mph it really takes off. Anybody know why this is? I have a van converted to 4x4 and for offroading it makes it basically useless as I have to maintain speed otherwise I will get stuck on anything but flat level ground. I've got 160/0 injectors and I don't know if this behaviour is "normal" or due to either the tuning/tranny/or4x4 conversion. Any ideas? Thanks!
If I'm on a hill and I'm starting from a stop, if I give it wide open throttle, the van takes a very long time for the rpm of the engine to get high enough to shift into 2nd gear. If it's steep enough, it won't move at all, and the rpms don't climb. With engine tuning off and on level ground, it takes a long time for rpms to climb - but once I get to about 25mph it really takes off. Anybody know why this is? I have a van converted to 4x4 and for offroading it makes it basically useless as I have to maintain speed otherwise I will get stuck on anything but flat level ground. I've got 160/0 injectors and I don't know if this behaviour is "normal" or due to either the tuning/tranny/or4x4 conversion. Any ideas? Thanks!
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Cross-Country
Joined: Mar 2020
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I searched through and read about that issue - but it seems to not match the symptoms others are having when they have issues throttle sensor or idle validation. My issue isn't that it won't go out of idle, but that the engine won't raise RPMs if there is any sort of load on it. It is reproducible and only applies when there is a load (such as a hill). If pull up a live view of sensors the throttle is reading at 100%. On flat ground if I turn on a tune it runs just fine, but even with the tune this only affects from a dead stop if there is a higher than normal load. On the hills, it slowly gets going faster and faster up until it hits 25mph or so and then it launches, but getting to 25mph could take a solid minute at full throttle.
There's a good chance I have a boost leak, but even then it simply isn't raising the RPM of the engine at all. It's almost like my torque converter is not allowing my engine to spin up since the wheels are locked?? I'm guessing it's normal to be able to floor it in Drive with the tires chocked and the engine will rev right?
There's a good chance I have a boost leak, but even then it simply isn't raising the RPM of the engine at all. It's almost like my torque converter is not allowing my engine to spin up since the wheels are locked?? I'm guessing it's normal to be able to floor it in Drive with the tires chocked and the engine will rev right?
FTE Chapter Leader
Joined: Jan 2005
Posts: 13,106
Likes: 4,714
From: Henderson, NV
I agree with the others that it is most likely your pedal or IVS.
If not, has the van got a 4R100 in it? If so, is the OD light flashing? If it isn't, does the OD light go on and off whenbtpu press the button on the end of the stalk?
If not, has the van got a 4R100 in it? If so, is the OD light flashing? If it isn't, does the OD light go on and off whenbtpu press the button on the end of the stalk?
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Cross-Country
Joined: Mar 2020
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I opened up forscan and the readings from the Accelerator pedal position sensor (APPS) and the Idle Validation switch ( IVS) are both good. APPS doesn't go above 75%which based on what I'm reading is more or less normal. I do have the 4R100 - and the Overdrive switch works as desired, with no flashing light.
I put a large rock in front of the rear tires and floor it. Without a tune on, it doesn't go over 1k rpm. With a tune (+80hp) it'll get the rpms high enough to spin the rear tires which is more or less What I'm looking for, but it seems strange that I'd need a tune to get it to go higher in rpms.
Just to clarify the difference between what I'm seeing and the reports I've read that are APPS / IVS failures - the engine is trying to do something, it just cannot. It feels/sounds like the load is so high, it simply cannot get up to speed. The transition from bogged down/barely moving to going fast isn't instant, you can hear the engine struggling but it very slowly increases in RPM.
Jason, I checked the IPR nut and it's tight.
I put a large rock in front of the rear tires and floor it. Without a tune on, it doesn't go over 1k rpm. With a tune (+80hp) it'll get the rpms high enough to spin the rear tires which is more or less What I'm looking for, but it seems strange that I'd need a tune to get it to go higher in rpms.
Just to clarify the difference between what I'm seeing and the reports I've read that are APPS / IVS failures - the engine is trying to do something, it just cannot. It feels/sounds like the load is so high, it simply cannot get up to speed. The transition from bogged down/barely moving to going fast isn't instant, you can hear the engine struggling but it very slowly increases in RPM.
Jason, I checked the IPR nut and it's tight.
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Hotshot
Joined: Mar 2014
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From: Douglassville, PA
The first thing you need to do is remove your tuning chip to eliminate that from the equation.
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Thread Starter
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Cross-Country
Joined: Mar 2020
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With tuner set to stock settings, front tire against a small curb and flooring it:
HPOP 2204 psi
IPR 31%
Do those seem like normal numbers?
Lead Driver
Joined: Oct 2005
Posts: 6,129
Likes: 1,919
From: Ponca City, OK
No it doesn't. If a weak hpop were to blame I would still expect the dc% to climb into the 60's. I see a frx and inline fuel filter in your sig, is the rest of the fuel system stock and intact? Have you monitored fuel pressure while driving? Fuel is power without it no mod or chip will make any difference. Do you get any codes even remotely related?
FTE Chapter Leader
Joined: Jan 2005
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From: Henderson, NV
Those indicate a relatively healthy HPOP but a small curb stopping the van while floored is not. I'm with udsuth78 on fuel pressure. What's that doing?
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Cross-Country
Joined: Mar 2020
Posts: 95
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I've got a fuel pressure gauge in a pod - it stays between 62-69psig at all times regardless of idle/WOT or tune selected. It actually got stuck in the parking lot yesterday because I couldn't reverse out of my gently inclined parking spot without putting on a high HP tune which blew smoke all over the place in front of my new employer. Embarrassing stuff.
Hotshot
Joined: Jan 2011
Posts: 18,849
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From: Puget Sound
The only time I've seen behavior like this is when the MAP line fell off. I would focus on the MAP - electrical connector, air line, what have you.
If that doesn't get you lathing tires from a stop, please feel free to log the behavior of the truck during the problem, and submit a copy of the log here.
RPM
MPH
EBP
MAP
EOT
TPS
MFD
IPR
ICP
FIPW
https://www.ford-trucks.com/forums/1...l#post16005729
If that doesn't get you lathing tires from a stop, please feel free to log the behavior of the truck during the problem, and submit a copy of the log here.
RPM
MPH
EBP
MAP
EOT
TPS
MFD
IPR
ICP
FIPW
https://www.ford-trucks.com/forums/1...l#post16005729