Hi all,
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Looking for help with my truck.
1996 F150, 4.9 6 cyl. 2 wheel drive, 5 speed manual.

Engine starts but will only idle. Zero response from gas pedal. Cable is connected and functioning properly.
Changed gas filter, no change.
Has dual tanks, no change when changing tanks.

Connected OBD2 device and got a code for misfire cylinder 4. Would that cause zero response to acceleration....?

Any suggestions to troubleshoot repair would be appreciated.

Thanks

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Here's a thread on testing the Throttle Position Sensor.
https://www.fullsizebronco.com/threa...stment.203080/
Are you sure the throttle cable is connected correctly at the accelerator pedal?
(The green dot was edited in previously to show a different issue)

 

If you can read the code, you should be able to read PIDS using your same scan tool
It should be under live data or freeze frame data
Once in there it will look up 239 pids and you will be able to look at a fraction of those
O2 sensor voltage and the Throttle Position voltage will be displayed
Verify the TP voltage changes with gas pedal movement
Watch the front O2 sensors switch

 

Hi soup bean, thanks for reply
yes cable is attached. Same results with hand activation in engine compartment.

Tested the TPS, here are the results. Can you help me understand...? At WOT ohms went wrong way......

Ohm meter at 20k setting
3.1
WOT = .29

 

Hi MM,
Thx for responding.
I don't have much confidence in the OBD2 device I borrowed from AutoZone........below are screen shots

 

Floor the gas and watch that TPS sensor pid
It should move up from 9.4 percent
You might be able to toggle your way into a voltage reding for the TP or use the graph on freeze frame to verify the voltage

 

Follow manicmechanic on troubleshooting. I don't have EEC V or live data experience.
Your ohms reading of .29, is 290 ohms, because your on a 20k setting. If it was 2.9, it would be 2,900 ohms.
290 ohms is pretty close to what you should see at wide open throttle, but a smooth transition between readings, as you sweep the throttle, is what you're looking for.
As you moved the throttle, was the transition smooth?
An analog volt meter is better in this test.
Without live data experience, my best generic advice would be to clean all your grounds and battery terminal connections, and check the PCM circuit board for leaky capacitors.
But, you've got live data, so go with that.

 

Hi, finally got back to it.
Got new OBD2 device, and after changing fuse port now works .

Yes TPS values change when I depress gas pedal.

Any advice is appreciated.

Thanks
Please see pics below .

 

You are doing those pid tests at idle, correct?
The fuel trims being negative means there is more fuel than air and the processor is taking fuel away
Faulty MAF comes to mind
The Maf and the HEGO's
You do not need to graph the O2 sensors,I just watch them switch
Graphing can help if you have an intermittent problem
If using a NGS
When in freeze frame data mode, you hit the button when a malfunction occurs and it will graph 5 seconds before the event and 5 seconds after
The calculated load of 88% has me going
That number is provided by the MAF or MAP sensor in conjunction with the TP
I'd disconnect the MAF in your case and see if it revs
It will not like having no MAF signal but should start and run, and if you mash the gas, it should rev
Some of the early MAF sensor connectors were no good
I'm no guru, still learning like the rest of you

 

Hi, yes at idle, barely idles at less than 500 rpms...

Any way, appreciate the support, I will try your suggestions.
Thanks