Alert for 4.2's that hesitate
 

If you have a 4.2 that hesitates when you hit the gas, read this.
Mine hesitated, had done it from day one, so I just thought it was normal. Till I drove another 4.2, and it didn't hesitate, plus it was quicker. So off to the dealer I went. They put it on the computer, no codes, but the service book suggested the MAF so they replaced it, didn't make a difference. The service tech said if I could leave my truck he would check into it.
What he found wrong is The Cam Position Sensor had been mounted backwards (180 degrees from what it should be), he installed it corectly. The end result is my truck does not hesitate at all now, it is now quicker without the Superchip in than it was before with the Superchip in, and the fuel guage needle does not seem to be moving toward the E as quick.
The way I see it, if one engine had the cam position sensor mounted backwards others probably do too. The OBD does not pick it up because the sensor isn't bad. The PCM simply disregards the sensor's signal, because it is so far out it can't be right.

------------------
Michael
99f150@pickupman.com
mkrieger@mailcity.com
99 F-150 XLT Supercab, 4x2, Bright Red/Harvest Gold, 4.2L, Automatic, 3.55LS, 255/70R16 Goodyears, Captains Chairs, Keyless Entry, CD Changer, Tow Package

Accessories: SuperChip, Donnelly Compass Mirror, Lariat Wheelwell Moldings and Bumper Cap, Ford Splash Guards, Bug Shield, Bed Mat, WeatherTech Deflectors, Mobil1 Synthetic Oil

Modifications: Painted Tailgate Handle, A/C on/off switch



[This message has been edited by mkrieger (edited 11-26-1999).]

I had the same experience but my after the dealer replaced the Mass Air Flow Sensor, my 1997 4.2l continues to hesitate. It is reallt making me crazy. Zf9UkrCan you give me any information about the cam position sensor? Where is it located, what does it look like, and how can I tell if it is mounted backwards? Any help would be really appreciated.

Thanks, Rich

I had the same experience but after the dealer replaced the Mass Air Flow Sensor, my 1997 4.2l continues to hesitate. It is really making me crazy. Can you give me any information about the cam position sensor? Where is it located, what does it look like, and how can I tell if it is mounted backwards? Any help would be really appreciated.

Thanks, Rich

Sorry for the double post but I was too anxious to send and didn't get a chance to edit for spelling.

Rich, now you know how the guy on the line who installs the Cam Position Sensor felt.

Rich, The CPS (cam position sensor) is located on the top of the engine where a distributor would be found (if it had one) to the right (right side of the vehicle) of the thermostat housing. The CPS is visible, but it sits on a synchronizer shaft that is not visible.
I'm guessing based on, the Tech. at the dealer had the #1 sparkplug out when I was there, that the CPS itself was in the correct visible position and that the synchronizer shaft was what was actually backwards (180 degrees out). If this is the case you would not know by simply looking at the CPS.
In any case if your truck hesitates, take it to the dealer, and suggest that they check the CPS.
I still cannot believe the difference. Before I would have considered the 4.2 comparable to the GM 4.3 (which I drive everyday at work) now I know there is no comparison, the 4.2 would smoke a 4.3 at anything.

------------------
Michael
99f150@pickupman.com
mkrieger@mailcity.com
99 F-150 XLT Supercab, 4x2, Bright Red/Harvest Gold, 4.2L, Automatic, 3.55LS, 255/70R16 Goodyears, Captains Chairs, Keyless Entry, CD Changer, Tow Package

Accessories: SuperChip, Donnelly Compass Mirror, Lariat Wheelwell Moldings and Bumper Cap, Ford Splash Guards, Bug Shield, Bed Mat, WeatherTech Deflectors, Mobil1 Synthetic Oil

Modifications: Painted Tailgate Handle, A/C on/off switch

Rich, Did you get your truck checked out yet? I'm curious as to what your trucks situation is.

------------------
Michael
99f150@pickupman.com
mkrieger@mailcity.com
99 F-150 XLT Supercab, 4x2, Bright Red/Harvest Gold, 4.2L, Automatic, 3.55LS, 255/70R16 Goodyears, Captains Chairs, Keyless Entry, CD Changer, Tow Package

Accessories: SuperChip, Donnelly Compass Mirror, Lariat Wheelwell Moldings and Bumper Cap, Ford Splash Guards, Bug Shield, Bed Mat, WeatherTech Deflectors, Mobil1 Synthetic Oil

Modifications: Painted Tailgate Handle, A/C on/off switch

Michael,
I haven't been able to get my truck into the dealer yet. I couldn't get a service appointment until December 22nd. I'll let you know as soon as I find out what they say.

Regards, Rich

So you are saying it came from the dealer like...this???

------------------
97F150/xlt/Blk/FLARED/regcab/auto/4x2/4.2/k&n/40flowmaster/Xenon H.I.D..
Platiums4/blueStrob/92octain/

I got an '98 Explorer with a sohc 4.0L and after long runs, such as highway travel or interstate travel, it will hesitate, even cut off if enough gas is applied.