I can see this problem has been discussed a lot here but I can't find one that quite solves it so I am posting mine.

The truck is a 95 with 5.8 E40D and dual fuel tanks.

The problem started out of nowhere. There were no symptoms leading up to it it just happened one day. It needed to crank about 6 times before it fired up and then it idles high (1200 rpm)

When cold it will start better and idle a little better (about 700 rpm) but when warm it will need to crank for a while. Sometimes it wont start until i floor the accelerator. Problem is same when running on either of the fuel tanks.

Also is a slight pinging when motor is under load at low cruising rpms. (maybe running lean?)

Plugs, wires, cap, rotor, are new

Air filter is clean

I have now replaced:
IAC
PCV

and tested
TPS

Next part I am looking at is MAP sensor but I ran into a problem. Both PepBoys and Autozone show my MAP sensor as this:



But I can not find that anywhere under my hood. Instead I find this:



I cannot find out what it is supposed to be. I assume it is the map sensor and something else as well. The part numbers dont come up on the stores computer or in a google search on my computer. The 2 numbers on it are PA66-GF33 T2 and F50E 9C915 AA. I bet someone here will know a little about this. Thanks for looking.

 

Can`t help you on the part ID but I would look for a vacuum leak and also pull the codes.

 

I have checked all the vacuum lines I could find with carb cleaner. I will take another look.

 

Im still stumped... Can any one out there tell me why my truck doesnt have the standard map sensor?

 

The photo under the hood is not the MAP sensor. I believe it is on the air passage way between the air filter and the intake manifold. Manifold Absolute Pressure is what the acronym means. You should first try to clean yours with an electric part type aerosol spray that claims not to leave any residue. Be very sure not to touch the very small wire.

 

You are thinking of the MAF, I am talking about the MAP.

Just ran codes and am getting

11
66
33

66=MAF sensor went below 0.4 volts during the last 80 warm-up cycles. OR TOT sensor output was less than Self-Test minimum value of 0.15 volts.

I believe 66 is because the battery had died while the truck sat last month. It may apply anyway, Im not sure.

33=EGR valve opening not detected. Probably came up because I was pulling clips off of sensors trying to listen to differences.

Im going to pull neg cable off batt to clear codes and try again.

 

OK, Im learning as I go so bear with me.

Starting fresh....

Same thing with key in run position:

11,66,33

1

then a series of single blinks

Now with motor started, after its self test and related flashes I get:

412,116,538

412=Cannot control rpm during KOER high RPM check

116=ECT out of self test range 0.3 to 3.7 volts.

538=Insufficient RPM change during KOER dynamic response test/ Operator error (MY FAULT)

 

your koer test was good... all those codes are caused because you forgot to hit the gas and do other stuff during the test. check the vac reservior, looks like a tomato juice can with two vac lines plugged into the end, should be on passenger side fender well. I had the egr code on mine and it turned out that the vac res was rusted out on the bottom but looked good from the top. just a thought but it worked for me.

 

Im still curious... Does anyone know what the sensor I have in the 2nd picture is? It is located near the evaporator housing under the hood. No one has been able to identify this part yet.

 

No-one........................?

 

I know it has been a while, but I am going to continue on this old post.

In the last couple years I have been slowly making progress.

I had a local shop diagnose a faulty ECT reading high or open. They replaced it and the truck ran better (but not perfect) for almost a week. It started having almost identical problems as before with difficult starting and ran rough all the time.

I decided to give another shot at solving it, got the manual and a volt meter, can't remember now how I came to my conclusion but after some trouble-shooting and reading codes I replaced the PIP sensor in the distributor. The distributor seemed in good condition. I don't have a timing light but i marked its position well before removing and reinstalled in the exact position. Afterwards though my problem was still present.

At this point decided to do some easier maintenance stuff like replacing the stock water pump and hoses. I found the lower hose had been sitting on the steering box and had almost developed a hole. While water pump was off I pulled the timing cover and inspected the timing chain. I had bought a new chain from Pepboys but the had apparently given me the wrong part which was not long enough or wide enough. I decided anyway that the stock chain was in great shape and I checked its slack to make sure it was not stretched, Also checked that it was in correct position and had not jumped a tooth on the timing gears.

So all back together I brought it back to the shop last November. They diagnosed a fault with the distributor and the TFI ignition module. They replaced both and truck ran well for a few weeks until the check engine light returned. When engine is started the idle will start at a normal 600-700 for a few seconds but then to rev up to 1200 for about 30 seconds. It still runs well but seems like its lacking a little. The chk eng light remains on all the time and the idle is generally high.

The codes I am getting now are:
KOEO
113 (Intake air temp signal high - circuit open)
KOER
113 (Intake air temp signal high - circuit open)
212 No tachometer input to processor - spout

I have not yet dug into the 212 code but I tried to get to the bottom of the 113 code recently. My IAT sensor is located on my airbox, I removed it and checked its resistance, It is right in line with what the manual list as correct. I also verified 4.6 volts across the connection to the IAT sensor. I plugged the sensor back in and pulled the PCM plug and verified the same correct ohm readings of the sensor across pins 25 and 46. So at this point I have ruled out any wiring problems or sensor problems with the IAT sensor. I dont know what else it could be, I have a suspicion the next source of my trouble may be the PCM itself.

Yesterday I also decided to attempt a fix to an exhaust leak I have developed a few years back. I believed it to be coming from passenger side. After a good couple hours of soaking the bolts with penetrant and moving the vacuum hoses out of the way I finally got the shorty headers off. Found a small burnt spot on the manifold gasket at the rear of #4 and some very tiny cracks that had developed at the junction of the 4 header pipes in the collector. I welded up the cracks, no other leaks or cracks were found. After reassembly with new gasket, I started and still have the same exhaust leak ticking away from the passenger side. I was frustrated after all the work with no difference.

So to relax Im taking a break today from trouble shooting and installing a CB radio. I have a week long camping trip quickly approaching and am trying to get at least the check engine light and related problems sorted out by then. Any help is appreciated.

 

Well, didn't get the cb in yet. Once I got under the dash I started cleaning up the ugly wiring from the factory alarm. I was surprised by some of their hacked connections to the harness. Oh well, its better now.

So any ideas on my issue with the IAT sensor problem? Does it sound like the PCM is malfunctioning?

 

The part in the second photo of your first post is called a Vapor Management Valve. It's a fancier version of the older CANP solenoid that allowed fuel vapors to be purged from the charcoal canister by opening a vacuum circuit leading to the throttle body.

Since your truck is MAF it does not use a MAP/BARO sensor. Ford figured out it is not necessary and discontinued using them around 1994 on MAF equipped vehicles.

Have you measured the actual IAT feedback signal it is sending back to the PCM? You should be using Signal Return (Pin 46) as the ground reference. When you measured the ohm value did you try heating and cooling the IAT to verify the output signal is linear and within range?

Code 212 can be tricky to track down. What color is the Ignition Control Module (TFI) currently in the vehicle? It should be black.

 

I did not actually measure the signal while the PCM was connected. I did thoroughly chk the sensor itself. I used a calibrating thermometer to verify temp and measures ohm of the sensor as I heated it within the ranges set out in the manual. All is ok with the sensor, no dead spots or jumps. I checked the same thing At the PCM plug with the sensor plugged in.

The current TFI is grey if I remember correctly.

 

Then you have the wrong one. Ford switched to a CCD (Computer Controlled Dwell) style ignition in 1994 for the F-series trucks. The previous style ignition was called Push-Start which uses a gray colored ignition module.

You need a black one. That is the most common cause of code 212.

You did a pretty thorough check of that IAT sensor. I wonder if you are missing the VREF signal to it?