i have been having a great deal of trouble with my truck on long trips in hilly regions. after about 50 miles or so of 65-70mph the truck boggs down when climbing hills, it will not drop out of OD and i loose all my RPMS, i have nothing even when i put the gas peddel to the floor, there is no power what so ever. engine light comes on and ford says its showing fuel system related problems but can not find anything wrong with it. Fuel filter is new. when i pull of the road, shut the truck off and restart it, everything goes back to normal until the next hill. If i drive in 3rd, this does not happen at all but my fuel is costing a lot of spare change. There does not seem to be anything strange about the tranny. Tranny is Automatic. any ideas out there?

thanks, bigdawg

 

That is wrong.
You either have a fuel pump going bad, a bad TPS sensor or a bad MAP sensor. It is possible that you may have an ECM going south.
The TPS is easy to test and so is the MAP sensor.
You might start looking for a better shop..................

 

This is just an "uneducated" guess and a general shot in the dark but here goes:
I know I have a 6-speed but my truck does the same on steep hills. I push the gas pedal harder and harder but I keep loosing RPMs and I loose power, although I don't get a Check Engine light. This happens until I remember to take it out of 6th and finally put it in 5th or 4th... I know, I know! I'm an idiot! But wait, I'm trying to explain: The 4R100 auto has a lockup torque converter, does it not? Maybe when the transmission gets hot, it can't realease the lock-up mechanism in the torque converter. Once you pull over and there isn't any load on the transmission, it gets "unstuck". In my case, I'm the faulty lockup mechanism and my not downshifting when I should is like simulating a stuck lockup clutch mechanism... I guess, or maybe it simply indicates that I'm a moron, I don't know. This would explain why nothing's wrong when you're in third gear since the lockup feature is only activated in 4th (OD). You'd think that if it was a fuel delivery problem, it would occur even more when you're at higher RPM (and the engine needs more fuel) such as when you're in third gear, but who knows...

You ought to make the Check Engine light come on again and then pull the codes (or have them pulled) to see if you have any of these:

P0700 Transmission Control System Malfunction
P0701 Transmission Control System Range/Performance
P0702 Transmission Control System Electrical
P0703 Torque Converter/Brake Switch B Circuit Malfunction
P0719 Torque Converter/Brake Switch B Circuit Low
P0724 Torque Converter/Brake Switch B Circuit High
P0740 Torque Converter Clutch Circuit Malfuction
P0741 Torque Converter Clutch Circuit Performance or Stuck Off
P0742 Torque Converter Clutch Circuit Stuck On
P0743 Torque Converter Clutch Circuit Electrical
P0744 Torque Converter Clutch Circuit Intermittent

If that's really what's wrong with your truck, then I think the only fix it is to replace the torque converter.

 

It's not the torque converter, the converter locks by grounding out the power, so it would unlock by allowing the power to be sent back to the converter. I have a switch in my truck to manually lock the converter and I can bog it down pretty good in od and it will try to pull just as hard as it can untill it has had enough and down shifts.

 

I guess it could be an electronic or electrical problem but could it still be possible that the clutch (lockup) actuation mechanism is getting stuck? It may be electrically actuated but the "thing" that actually makes it lock up still has to be a mechanical device. In this case a "something" that sends hydraulic pressure to force the clutch disk attached to the turbine inside the torque converter against the front cover of the torque converter. A valve of some sort perhaps? Is it the valve that sends hydraulic pressure to the clutch that's failing or is the solenoid that opens and closes the valve? Who knows. I'm not sure where the valve or the solenoid is. I had heard before that if the "lockup" function failed, you had to replace the torque converter but this may not be applicable to the 4R100. (Or maybe it was BS and isn't applicable to any transmissions...) Now does he have to physically stop the truck, or physically stop the truck AND shut it off to reset it or will just killing electrical power eg. shutting off the ignition reset the transmission? If just killing the power will let the "sticky" solenoid release or reset the computer then I guess it could be an electrical/electronic problem, but if he has to remove load from the transmission so that there is no longer any hydraulic pressure being developed by the transmission then it may be a mechanical problem. Maybe he can try to put in in neutral with the engine running (and power on) while the truck is still moving to see if it's the clutching mechanism's valve. (This would only work if whatever makes hydraulic pressure doesn't make hydraulic pressure while the transmission is in "N" of course.) On the flip side, if cycling the ignition key on and off with the truck still in "D" resets it, then it could be an electrical or electronic problem then, right? I don't know, I'm just throwing ideas out there. SM, what do you think?

 

The problem is that he states that he loses power untill he is on the side of the road, I leave my converter locked untill I am almost stoped, so even if my truck down shifts, the converter is still locked, the truck just bogs untill the rpm is to low and then the truck down shifts to 3rd and keeps right on going, whats weird is that his tranny stays in od (4th) no matter what, it starts to bog (normal) on a hill and then he is losing power and the truck bogs to a stop in od. Ford is saying it's fuel related, it would be missing out if it was that, really missing out trying to get up to speed. Anyone think it's the rear end sensor? Tranny problem? Maybe it's a ecm (computer) problem? I don't know why if it is hooked up to Fords computer why the can't pull the codes and figure it out...

 

Oh I see what you're saying. I guess I didn't understand his problem completely. So the problem IS NOT (just) the converter staying locked, it may be that the command to downshift isn't being issued or not being received or maybe simply not being executed when the engine senses "load". Or maybe the engine doesn't sense "load" correctly anymore so it doesn't know to make it downshift. Load, I think, is calculated by how wide the throttle is open (by the TPS) versus how much volume of air is flowing through the MAF, so maybe, like V10Mars says, it could be (one of) these two components adding to the problem. Wouldn't the VSS give you a few signs of going bad though? Like the speedometer needle jumping around or not registering at a certain speed, the ABS light might be on since the VSS is used as a sensor for the rear channel ABS. What's interesting is that he says it doesn't happen when he keeps it in third. The only difference between 3rd and 4th (other than 3rd being a 1:1 ratio and 4th being a 0.71:1 ratio) is that (I believe) on a stock truck, the lockup feature is enabled and can only be turned on in 4th gear, isn't that correct? He doesn't say it bogs down all the time, just when climbing a hill so it may be downshifting to 3rd and 2nd and 1st at some point. Hard to say with so little info. It would be interesting to know if after having the power loss happen on a hill if he could come to a complete stop, leave the engine running, leave it in "D" and then try to take off again. If it bogs down while trying to get going again, then it stayed in 4th and/or is stuck in 4th. Codes would be helpful though. That, and someone at his dealer who knows what he's talking about. (That "someone" sure isn't me, that's for sure... on that note, that would be my cue to stop posting useless crap. )

 

BigDawg,

Do you have a super chip in your truck????

 

The tranny (4R100) can lock the converter in 2nd 3rd and 4th, the only gear it will not lock in is 1st, under normal driving 3rd will lock at about 35mph. Again even if the converter stayed locked (as mine does) it would cause no problems, most people probally wouldn't even notice. Good point on the VSS, guess there would be some signs of that...

I can lock my converter in any gear at any time, even stall it if I flip it at a stop sign. The only gear I can't lock it is in reverse, kinda weird there is no way of getting around it.



Does this mean it's time for me to quit posting usless crap too, lol

 

No no, you HAVE to continue posting. I'm just out of guesses plus unlike you, I don't have a 4R100 to look at. (That may be a good thing?)

I didn't know the TCC could be engaged in 2nd and 3rd gear in addition to 4th. That's interesting and a great idea. I guess they were trying to squeeze as much mileage as they could. I hope he posts some codes soon. I'd be curious to see what it was.

 

thanks for all the suggestions, i'll see what the guys at ford have to say. probably just...duh duh duh whatcha macallit??? LOL