Hello all, I have a 1997 f150 4x4 with the 4.6L, Last week it sat all week and the battery went dead. Because of a loose battery cable I think. Now my air bag light is on with a 52 code. Which I have read about it being a low voltage code. Now for some reason after I drive the truck and I gets warmed up it it stalls everytime I stop at a stop sign or slow down for a turn. I already replaced the idle air control valve, spark plugs, and ran some injecter cleaner thru it. Any ideas would be greatly appreciated. Thank You.

 

I did some more checking and has any one ever heard of a back up battery for the computer. If that went dead after sitting for four days I was told I have to go to a ford dealership to get to computer reflashed. Has anyone ever had to do this?

 

Provide answers too these questions.
1. Does the motor go high idle when cold started?
2. What is the idle speed when fully warmed?
3. Are there any codes set?
4. On the road coming to a stop, does the motor want to keep pulling the truck?
5. On slow down or decelleration, how does it act before stopping?
6 Is there a fuse blown that feeds the computer? If yes then the computer is being rebooted every time the motor is started.
7. What happens if you put the trans in neutral and cost to a stop?
These questions may give a clue to the fault.
Good luck.

 

Answers-

1-yes around 1200

2-In neutral around 600rpm and in gear around 400rpm but if i hold the brake and tap the gas it will stall

3-the air bag light is on and it flashes 5 times and then 2 times for a code 52 which i was told is a voltage lost code. The service engine soon light has not come on at all

4-no it doesn't pull the truck but when I slow down I watch the tac and it will down shift thru the gears and when it gets to first the rpms will drop to 400 or lower and then stall, after i drive for about 5 mins.

5-see answer to #4

6-I looked for a blown fuse but I am not sure witch one I am looking for If you could point me in the right direction that would help alot

7-If i put the trans in neutral it will still stall. but after I restart it it will idle really low unless I hit the gas peddle a little bit and let it settle down it will idle perfect and will stay like that till i put it in gear.


I hope I answered all your questions. I really appreciate any help you can give me and thank you for your time.

 

#2, 4 and 7 are the indications of an IAC that cannot contol the engine idle.
The cold start is ok but when the engine is hot, the control stops.
This is what you need to find.
Check the plugup/harness for a problem.
The hot idle should be no less than 650 rpm +/- a small amount.
The reason the motor stalls on decelleration is as follows;
The TPS is cloesd down while the truck is "moving".
This tells the IAC to close down to just enough air to keep the motor from stalling. (your stall)
The fuel is cut down to improve mileage (adding to the problem) and is normal.
The program table updates are done during this low activity time period.
With the fault present, the transmission converter adds loading helping to cause the stall.
You can see how important it is to have this device fault free.
The air bag issue and codes are seperate form engine codes and have no relationship.
You need to get a copy of the owners manuel so you have the fuse assignments and locations.
There are two fuses involved with the memory. One is on a fuse panel, the other is not.
A way to tell what is going on is use a good "scanner" to look at the 8 monitors for being complete. If they are always incomplete, a code 1000 will be set because they are always being rebooted at startup if a fuse is open.
Sorry it's seems complicated but we all are running computer controlled vehichles and it won't get better anytime soon.
This is the meaning of the saying "education is king over the long term". You cannot be fooled for long if you are in the 'know'.
Bottom line is don't just follow all the time.
Good luck.

 

How to clean the MAF (Mass Airflow Sensor) in a Ford F150

I went to the site above and cleaned the little wires on my maf. It was really easy since I sprayed the wires while in place since I didn't have the torx bit (mine required a "security" torx with a hole in the tip). I used a magnifying glass to see the wires, and sprayed the heck out of them. They went from black to bright silver!

Anyway, the fix cost me 6 bucks for the electrical contact cleaner (Home Depot), and my truck has stopped stalling, pinging, and has quite a bit more power.

I hope this helps.

 

My 97 F150, does the same thing, mine is a 4.6L, with RWD. It has alot kms on it, but recently, after driving around for a while. I come to a stop and the car idle drops quickly and either stalls or nearly stalls. Wouldn't be a big deal but it happens during slow turns and my truck is heavy without power steering.

I cleaned the MAF, did an oil change, changed the plugs and wires, air filter , i also cleaned out the injector with a cleaner as well.
I even started using 91 octane in hopes to add a boost.
I am wondering if there is a way increase the idle without a computer.

It is not only embarrassing but unsafe for my neighbours bushes.

I also read that there is a solenoid in the transmission behind the filter that my be faulty, and can cause the same problem. I was thinking of changing the filter in my tranny(over 500k on it). So why not swap it out?

Or..

should i focus more on the gas/air intake.

Engine was just swapped and i don't suspect any problems there.

Thanks. first post btw.

 

f150_eh, review my post #5.
You have an IAC issue.
Clean it.
You cannot alter fixed idle stop or you get into cold start problems and other issues.
Leave everything else alone and get the IAC to control idle like it is supposed to do.
Good luck.

 

K.. so i cleaned out IAC.. the part it self and the 2 piston chambers on the engine with q-tips and cleaner they where all very dirty.. i believe that they are clean now.. thanks for the tip.

Unfortunately, it still stalls..?
Although i have seen a huge change in performance..

i noticed today the my check engine light was missing or broken?

My landlord who is a mechanic, is bringing his personal scanner over and going to plug it in.
What am i expecting to learn from this?

You can tell that i am new to this.Thanks for the help..

 

You don't do it with Q tips.
Remove it and use spray can Throttle body cleaner until it runs out clean.
Do the same with the throttle body plate and insides without taking it off..
After this you should do a reboot of the PCM.
.
Normal operation for cold start is to go high idle then it comes down to about 750 rpm as the motor heats up.
Anything lower than 750 or no high idle indicates the IAC is stuck closed because it controls the air bypass around the throttle plate.
You may have other issues but clean this up first.
Good luck.