Hey ya'll I have a problem maybe someone out there can help me with. I have a 98 F150 with the 4.2 and auto tranny. 75000 miles. During acceleration and cruising speed of about 70 MPH I get repeated hesitations. The truck runs fine during city driving though. I took it to a service shop and had the engine hooked up to the machine. They told me that it was the #1 cylinder plug misfireing. I have Changed the plugs and wires and that seemed to fix the problem for about a month or so, but now the problem is back and growing steadily worse. I am planning on taking a long road trip soon and to be honest with you i am not sure that i trust my truck anymore. I loved it until all this started. Ford seys there is nothing wrong with it. I am tempted to go back to chevy after the things I see ford "does" for/to their customers!!!
Thanks for any help you can give...

 

MY truck is a97 4.2 5 speed.it hesitates between 2200 and 2800 rpm.Then around 3000 rpm it recovers.It does it all the time.After long trips on highway about 2 hours it wants to stall when returning to city driving.i thought i was fuel injectors or O2 sensor.But with todays cars who knows!

 

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|(-) (-) (-) (+) |
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info for darick harriger
It maybe the truck has a bad ignition coil pack it maybe opening with road vibation. this type coil fires two cylinder at once. the drawing above is the wires (harness side) to coil (+) is pos.(+12v) and (-) is ground be sure to check the primary and secondary resistances of the coil. The primary resistances should read 0.3 to 1.0 Ohms and secondary should read 6.5 to 11.5k Ohms (k = 1000) If it is out specs replace the coil pack. Coils pack are sold in auto parts stores like Autozone for your truck. This applies to all 4.2L V6 engines from 1997 to 1999.

1999 F150 XLT SB 4.2L V6 5 speed trans white

 

* -----
* | Sig-|--* -signal to computer
* | GND * -ground from compter
* | REF_|--* -reference from
* ----- computer (+5)
info for MTO669
That sounds like a TPS (Throttle Position Sensor) problem. With engine off and key on. Check the wires see if there is a 5 volt beween (Ref) reference and GND, and check beween (Sig) and GND it should read 1.0 volts to 5.0 volts when the throttle is moved from close to full open. If you see voltage drop to zero when you are moving the trottle. The TPS is bad replace it.

 

STEVENF150 is King, boy, I wish you would come fix my truck since I have the same problem as MTO669, but a little worse, it just will quit at any time I stop after driving at high speeds.

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Black 97' F-150 XLT Flareside, 4.2 6 CYL., 5 Speed
Deflecta-Shield lighted visor
ExTang Tonneau cover, Westin Nerf Bars,
GTS hood and window deflectors
Manik 4x4 pushbar, Hyper-Blue Headlights, Lund Shadow Cowl
265-75r-16 Pirelli Scorpions, Tinted Windows
Huge Stereo!, Ford factory alarm and entry
And many More Goodies To Come !!!!!!!!!!!!

 

I am having the same problem. It seems a little worse with warmer weather. Did anybody actual fix this prob yet??

edcallahan@bestoffers.net