To anyone who may read this:

We've recently purchased our second Ford truck ('92 F150 Super Cab XLT, and retired our '87 XLT). When we got our '87 three years back, it wasn't expected to make it through the winter. It had more wrong with it then right. I made some minor repairs, and nursed it along; it only had to ride me back and forth to work. It's still going, but I'm avoiding changing out a leaking front tank and doing the required bodywork.

We got our '92 back at the end of July '03. It had set under a maple tree for about a month, had a low tire, and really smelled like dogs. But the whole family loved the fact that the five of us (me, my wife, and three young daughters) could all ride at the same time.

The day we got the truck, we took it to Sears to have the tire fixed, and the alignment checked. That's going to be another story... (Soon as I fix the passenger side rotor, front brakes, etc. The guy at Sears also suggested using a cut onion to help with the dog smell.)

My first step with the truck was to figure out its gas mileage. I ran the front tank until the engine sputtered. I switched to the back tank, and filled-up the front. I ran the back tank until the engine sputtered for it. I switched over to the front tank and reset the trip odometer, and filled-up the back tank. This is when the “fun” began.

For the next couple of weeks, I started my day with a truck that would start right up in the morning, run a few moments then stall. It stalled when I'd pull out of my driveway. It would almost shut down going up a hill (part of my everyday travel to work). It would ride rough on a straight stretch and shut off at various traffic lights. (Also, I started to notice the idle and battery gauge operating together. The gauge would swing low with the idle and high if I hit the gas.) By the time I got to work, the truck was warmed up and would run fine the rest of the day. (So I tried running the truck for a few minutes each morning to warm up, it would still stall.)

I tried to determine if the problem was fuel related, alternator related, or exhaust related. In my 'novice' opinion, I decided that the problem had to be related to the fuel line. (Really, hoping I didn't screw something up running the tanks empty, or hoping that I wouldn't have to deal with dropping a tank or tanks to change out a fuel pump.) This is where I ventured into the realm of the Ford's high pressure fuel lines. We made several trips to the auto-parts store for: a fuel filter, '92 ford repair manual (wanted Chilton, found a Hayes), plugs, wires, and an oil filter. After internet searches and finding this site, , I found out about the *special* tool required. We ended up buying two versions! The first (a NAPA product) resembled a multi-ended pair of pliers. Once I figured out how to use the tool by inserting the smallest end into the end of the fuel line, I found out that it was too big to work with this my size line. (The end marked 3/8ths was not that small!) I started modifying that tool while my wife went out and purchased a different tool. (My modification never worked.) The second tool was actually a set of several plastic socket-like items split down one side to slide over the line and push into the end of the fuel line. After a 'very' tough time removing the fuel filter (I suspect due to it not ever being changed), the new filter went on in seconds. I then moved on to the plugs and wires. I don't know how the engine ran on the old plugs / wires. The old plugs gap measured ~.072.

After these minor tune-up efforts, the truck did seem to run better, but it still had problems stalling and it seemed to be running 'tense'. (My wife describes it as hesitant.) The 'Check Engine Light' would come on ~7 (5-10) seconds after starting the engine. And now the transmission was starting to shift hard. I ran some fuel injection cleaner through each tank, again not noticeable change. Then I did some searches on this site and took the truck to Auto Zone (Store #1827, and dealt with Tony) to have the codes read. Here's the information on my truck and its codes:

VEHICLE:
1992 FORD TRUCK
F150 1/2 TON P/U 4WD
8 CYL 302 N 5.0L FI

TROUBLESHOOTING ECM TROUBLE CODE:
112: AIR CHARGE SENSOR
122: THROTTLE POSITION SENSOR (TPS)
412: THROTTLE AIR BYPASS

Per Tony's suggestion, I started with checking the 'Throttle Air Bypass' for carbon build up. I removed the part to find it looked fine.

I disassembled the unit to separate the solenoid. Connected the Air Bypass Unit back-up, started the engine and watched the solenoid to see if it moved at all. The separated bypass unit seemed to work ok. If you press where the solenoid should it seemed to allow air-flow and the engine idle would pick-up. The solenoid showed no sign of movement.

My wife (and kids) went back to Auto Zone to pick up all three parts (~$100).

I changed out the Throttle Air Bypass (It was the easiest to get to.)

I started on the Air Change Sensor (I removed it using a closed-end 1" wrench.) I quickly replaced it with the new part, trying not to lose too much anti-freeze. When I went to re-connect the wiring harness, I found out that the new part was not made the same as the old part. The connection to the wiring harness was a mirror image of what it should have been. It was returned to Auto Zone and a correct part was found at Advanced Auto Parts (Store #01243).

While waiting for a replacement Air Change Sensor, I started work on the TPS. This part turned out to be screwed (with two phillips-end screws) on to the bottom of the throttle assembly. I removed two bolts from the top of the throttle assembly and four connecting the assembly to the engine, one holding a plate near the side of the assembly and disconnected several wiring harnesses. With the throttle assembly somewhat loose, I pulled it out and twisted it over to change out the TPS.

After putting everything back together, and reconnecting the negative battery terminal (said to allow the computer to re-learn it idle during the first minute after start-up), the truck started without any indication of the check-engine light! After an extensive test drive, the truck no longer has any hesitation and it's shifting fine also.

I want to thank everyone on this site who discussed various problems that helped me with the fuel filter, and other issues. And a special thanks to Tony of Auto Zone, he was a wealth of information specific to my problem.

 

GanM_92SuperCab,

First off, welcome to the site !!!!

And to your post, that is what we and this website (among many other sites) is all about. Helping others who don't always have the resources to figure stuff out is what makes this an awesome site.

Have Fun & Keep on Truckin'
Dean

 

If you lost antifreeze when you changed the air charge temp sensor then you changed the wrong sensor. You probably actually changed the coolant temp sensor. (They look similiar on the outside) The air change temp sensor screws into an intake runner, not a water passage.

 

Welcome to the club, I have the same truck as you btw, minus the extended cab.

 

Welcome to the club. I also have the same truck as ccnseven.

 

Thanks for the info, I didn't expect an air change sensor to be associated with the coolant system. That's probably why the first new part didn't fit the old wiring harness, which caused me to return it. And my wife took the original to the other store and they did give her the coolant temp senor. At least I don't have the right part in the wrong spot.

 

I went back to my truck to check for the Air Change Sensor. Found it on the driver's side of the engine close to a fuel injector. Pulled it out, it was pretty bad looking, so I replaced it also tonight. The guy at Auto Zone got a laugh () out of my request for the same part that we returned yesterday.

Thanks again for the help!

 

No problem