I HAVE A 97 F-150 4.2L AUTO 4X4. THE TRUCK SEEMS TO SURGE OR HESITATE AT PRETTY MUCH ALL SPEEDS.DOES ANYONE HAVE ANY FIXES FOR THIS OR THE SAME PROBLEM? I HAVE HAD THE TRUCK ON FORDS SO-CALLED SUPER "SBDS" COMPUTER AND THEY FOUND NOTHING. AM TAKING IT TUESDAY TO HAVE THE O'2 SENSORS AND CAT. CONVERTORS CHECKED AT A LOCAL PARTS/SERVICE STORE. ALSO FOUND OUT TODAY THAT MY SPEEDOMETER IS 5 MPH TO SLOW(doing 65 but speedo only registers 60). CAN SOMEONE PLEASE HELP OR GIVE ME SOME IDEAS ON HOW TO FIX THIS(these)PROBLEMS? THANKS IN ADVANCE FOR ANY HELP ----TONY----

 

I don't know how many miles you have on your truck, but I would suggest that you have your injectors and throttle body cleaned. I had the same exact problem with my pickup. It made a difference. I wouldn't think that a 1997 Ford truck would need it yet, but if your over 40k miles, it would be worth at least having them looked at.

 

WHEN YOU SAY TO HAVE THE FUEL INJECTORS AND THROTTLE BODY CLEANED, DO YOU MEAN WITH A FUEL TANK ADDITIVE ? MY TRUCK ALSO DOES NOT WANT TO START ALL THE TIME. SOMETIMES AFTER IT SITS FOR AWHILE,WHEN I START IT,IT SPITS,SPUTTERS AND ACTS LIKE IT DOESN'T HAVE ANY FUEL-THEN IT STALLS.IF I TURN THE KEY OFF AND THEN BACK ON-WAIT FOR THE FUEL PUMP TO STOP RUNNING,IT STARTS UP.DONE A OVERNIGHT LEAK DOWN TEST USING A FUEL-PRESSURE GAUGE HOOKED UP TO THE SCHRADER VALVE ON THE FUEL RAIL.DIDN'T LOSE ANY PRESSURE.BUT IT DON'T DO IT ALL THE TIME SO I AM KINDA FRUSTRATED WITH THIS TRUCK.FOR A 4.2L V-6 WITH 205 HP,IT SURE DON'T FEEL LIKE I AM GETTING THE FULL 205 HP.WHAT KIND OF FUEL MILEAGE DO YOU GET? I AM GETTING 13 MPG.MY TRUCK HAS 51,000 ON IT. WELL THANK YOU FOR ANSWERING MY POSTING----TONY----

 

Of course your truck is completely different than mine, but, I know for a fact that your injectors will benefit greatly from an injector cleaner. The additive only keeps the injectors clean, you need to have the injectors/throttle professionally pressure cleaned. I think most lube shops or mechanic shops have the machine, and depending on where you live it shouldnt cost more than 75 dollars. My 1993 F-150 4x2 cost about 60 dollars? with my tailgate down and no ac and 65 mph, I got 22.1 mpg. My 1989 will not get over 14-15 anytime, basically because its an earlier EFI and 4x4. I would say that a new F-150 6-cyl, and normal driving should get about 17-18, maybe more...








Evan A.K.A. PastMaster
1993 F-150 302/E40d XLT
1989 F-150 302/Aod 4x4 XLT Lariat

 

I WILL HAVE THE INJECTORS AND THROTTLE BODY PRESSURE CLEANED.DO YOU THINK A BAD FUEL PUMP WILL CAUSE THE SAME PROBLEMS? I WANT TO SUPERCHIP THIS TRUCK AND PUT A DUAL EXHAUST ON IT BUT I WANT IT RUNNING RIGHT FIRST.MY FUEL PRESSURE IS ON THE LOW SIDE AT IDLE AND AM WONDERING WHAT THE FUEL PRESSURE IS DOING WHILE THE ENGINE IS UNDER A LOAD. THANKS----TONY----

 

A fuel pump may give you problems, but what I've heard is that when they are about to fail they have a really loud humming noise. Have you replaced the inline filter? That may be a problem to. I have a HyperTech powermodule on my 93 302 and I hate to have to run 89 octane in it to get the module to work properly. I honestly think that it is a waste of money. On the new F-series it may be better. Who knows?







Evan A.K.A. PastMaster
1993 F-150 302/E40d XLT
1989 F-150 302/Aod 4x4 XLT Lariat

 

WELL,I HAVE HAD MY FUEL PUMP REPLACED UNDER MY EXTENDED WARRANTY.THE PROBLEM IS NOT AS BAD NOW,BUT STILL THERE.IF I TURN THE KEY ON AND LET THE FUEL PUMP RUN AND THEN STOP,THERE IS NO PROBLEM AT ALL WHEN IT STARTS.PRETTY WEIRD HUH!!
WELL NOW I WANT TO TRY AND FIND A DUAL EXHAUST FROM THE CAT BACK.TALK TO YOU LATER.----TONY----

 

Mudder:
I just ordered the Gibson Supertruck and I can't wait til it gets on my truck. I have a 5.4 but the same one will fit on the 4.6. Cost 269 plus tax/shipping = $315.
Marv

 

I have a 1997 F-150 XLT, and have had the same problem at start up with my 4.2 v6. After some research, I replaced the coil pack. It solved the problem, or at least I thought it did. I had no more problems for almost 3000 miles and then it started again. But not as bad. I think I am going to have the injectors cleaned and then change the spark plugs and the coil pack again if necssary. It only cost about $63 and I did it myself. Also, my truck is a 5 speed and gets about 25 mpg on the highway, 17 in the city. You only get 205 horsepower at 5500 rpm. You really need to torqe it up to around 2500 or 3000 to feel like you got any power at take off. But I still like it.

 

Hi,
I have a 1998 4x2, regular cab short-bed,23,000miles, 4.2, 5spd,3.08 gears. I only get 18-20 on the highway with a K&N filter installed a couple of weeks ago.
I drive 70 to 75 mph to work daily.
Have you did any mods to your truck to get 25mpg?

Thanks,
Richard

 

I own a 1998 F150 4.2Lv6 and it has a miss and bad hessitation. Ford had it in on their machine and said it had a clean bill of health. I beg to differ....has anyone else had these problems...?

 

You might want to look into replaceing your fuel filter also. Just replaced the one in my Mustang and can tell the difference already...

97 F150
4X4 ORP
5.4L V8
37000 mi

 

check to see if your fuel pressure regulator is bad i have the same problem with mine with no sucess noone seems to know whats wrong with it spits and sputters at startup then runs fine after about 5 seconds coilpack was changed but still does it spark plugs are carbon fouled and exhaustr tips are black i replaced the wires plugs and fuel filter with no success but to let everyone know that 4.2s have problems with rocker arms wearing out so if you have a noisy valvetrain have your pushrods replaced mine needed it it also lacks power after warm up hesitates misses whatever you want to call it and the funny thing is its under warranty still but they give me a hard time about fixing it since they seem to think its fine very doubtful in my mind since ive been a mechanic for 6 years i know tons about motors but this time im stumped

 

Have ford replace Fuel Pressure Regulator - IT's FREE!!! - It's a recall item and while they are in the fuel lines have them install the inline check valves!!! This is what has caused all of the problems of hesitation and no start unless making fuel pump build up pressure before cranking...

REASON - the check-valve in the regulator leaks if it is old and corroded... My was stuck closed and was burning rich!! no return to the tank and 100+ FUEL PSI!! Definatly a saftey concern!!



Screw the spelling and fix the truck!!