F-150 Problems

[jeff_t]

Not familiar with the engine compartment of your truck, but follow the tube back from the filter box. It will be attached to the throttle body. Pull that tube off (probably a hose clamp holding it on), and you'll likely see the throttle plate stuck open. The cable will be attached to linkage on the side of the throttle body, along with another cable for the cruise control if you have it. It's likely stuck open because it's gunked up, or the cable is bound up somehow. It's not rocket science, you can take it apart and clean it. Take a couple of pictures if you think you'll have trouble putting it back together.

 

[Gary_602z]

The fact that the pedal is down to the floor tells us that it is something in the linkage,throttle plate or cable. Find that and I will bet your problem goes away.

Gary

 

[Battenkiller]

I was going to bring up that the main problem is that you got a Ford, but I won't. ;-) lol

Do the Ford's have a throttle position sensor, I think that is going bad on my Durango and it wants to surge at idle from time to time.(not wide open like yours does though)

Had that on my Power Ram. It also made the speedometer jump from zero to like 80 MPH and back over and over again. Weird.

Jeff, makes sense what you are saying. I'll get out there first thing in the AM and pull it apart.

I hate working on trucks. Not only am I only 5'6" tall, I'm almost that deep. Dang beer belly gets in the way of leaning right in there once I'm up on the stool. :red:

 

[ssupercoolss]

is the (for lack of a better term) "throttle return spring" inside the cable assembly from the pedal to the throttle body on the fords? we had an older chevy diesel and the cable broke which in turn sent the engine to "max rpm". i would be looking at the cable since the pedal is on the floor.

 

[amateur cutter]

That truck is port injected throttle body with iac. Only way to get to 6k RPM is with the throttle plate open. Likely gummed up as stated, as well as a binding cable. Likely an easy fix. Throttle body controls air flow only after pedal is depressed, ecm uses tps, o2 sensor, & crank & cam position sensors as well as maf & map sensors to extrapolate fuel delivery 3-5 times per second. Clean the throttle body with brake cleaner & a toothbrush ( no need to remove ) Yes use brake clean, not carb cleaner, the brake cleaner evaporates very quickly & won't flood the thing. Ck engine lamp is likely a wot warning. Ford obd II ecm will set a code for over rev in neutral or park. Sea foam & fresh fuel are a good idea as well. Engine run was likely caused by the open throttle plate & excess fuel from the rapid cold rev as the engine gets a richer fuel mixture till it's up to temp. Reset the code & all adaptives in the ecm by disconnecting + & - cables, & touching them together foe 10 sec. This drains all excess voltage from the ecm & gem module & "reboots" the computer. My guess is your problem will be solved. Hope this helps. A C

 

[DanCorcoran]

That truck is port injected throttle body with iac. Only way to get to 6k RPM is with the throttle plate open. Likely gummed up as stated, as well as a binding cable. Likely an easy fix. Throttle body controls air flow only after pedal is depressed, ecm uses tps, o2 sensor, & crank & cam position sensors as well as maf & map sensors to extrapolate fuel delivery 3-5 times per second. Clean the throttle body with brake cleaner & a toothbrush ( no need to remove ) Yes use brake clean, not carb cleaner, the brake cleaner evaporates very quickly & won't flood the thing. Ck engine lamp is likely a wot warning. Ford obd II ecm will set a code for over rev in neutral or park. Sea foam & fresh fuel are a good idea as well. Engine run was likely caused by the open throttle plate & excess fuel from the rapid cold rev as the engine gets a richer fuel mixture till it's up to temp. Reset the code & all adaptives in the ecm by disconnecting + & - cables, & touching them together foe 10 sec. This drains all excess voltage from the ecm & gem module & "reboots" the computer. My guess is your problem will be solved. Hope this helps. A C

Congratulations for a very well-written response. I don't have any interest or knowledge of fuel delivery systems, but I could understand (and could have followed) your instructions.

 

[Battenkiller]

That truck is port injected throttle body with iac. Only way to get to 6k RPM is with the throttle plate open. Likely gummed up as stated, as well as a binding cable. Likely an easy fix. Throttle body controls air flow only after pedal is depressed, ecm uses tps, o2 sensor, & crank & cam position sensors as well as maf & map sensors to extrapolate fuel delivery 3-5 times per second. Clean the throttle body with brake cleaner & a toothbrush ( no need to remove ) Yes use brake clean, not carb cleaner, the brake cleaner evaporates very quickly & won't flood the thing. Ck engine lamp is likely a wot warning. Ford obd II ecm will set a code for over rev in neutral or park. Sea foam & fresh fuel are a good idea as well. Engine run was likely caused by the open throttle plate & excess fuel from the rapid cold rev as the engine gets a richer fuel mixture till it's up to temp. Reset the code & all adaptives in the ecm by disconnecting + & - cables, & touching them together foe 10 sec. This drains all excess voltage from the ecm & gem module & "reboots" the computer. My guess is your problem will be solved. Hope this helps. A C

Congratulations for a very well-written response. I don't have any interest or knowledge of fuel delivery systems, but I could understand (and could have followed) your instructions.

I agree. I have a passing knowledge of these things, but AC's explanation was crystal clear and very helpful. But I had already discovered that he was correct about the stuck throttle plate (interesting to find out that only air passes thought it). It was stuck pretty good. I went for the Gumout (nice to know about the brake cleaner), but it was packed away somewhere because we're moving. I found a can of WD-40 and gave it a good spray and worked the plate back and forth. I got back in and started it up and it started fine... then stuck open all the way again. I shut it off immediately and went back and sprayed it some more. Got back in and started it up (ran real rough for a few minutes from the WD-40) and let it warm and worked the pedal.

It gradually went from returning slowly to returning normally. I decided to take it for a test run. It seemed fine, so I kept right on going to Advanced Auto to get some Sea Foam and whatever they suggested to get to clean the throttle plate properly (didn't want that happening again at 75 MPH on the Thruway) and to use their code reader to see what the truck might need.

It ran fine all the way into town. As I pulled into the AP parking lot, I thought, "Now there's that gas smell again." As I parked I noticed a squealing sound as I turned the wheel, like I turned the wheel too far and was getting a belt squeal, only I hadn't. Did the same thing when I turned it in the other direction. "H-mmmmm. Now what?"


Part II (continued on another thread)

 

[DanCorcoran]

The sound of someone removing Brazilian shrubbery...