my 1995 5.8 f-150 is sick! over-drive light is flashing missing really bad. without driving it, if i put i in drive or neutral it smooths out but in park or reverse misses bad. i have change the neutral position sensor on the side of the tranny, still acting up! before all this happen it would at times miss bad when cold and smooth right out after warmed up. i have lots of codes but don't want to change everything because it may be a deeper problem. any thoughts would be appreciated.

 

The codes will tell you why the OD light is flashing.
Pull the vacuum pipe off of the fuel pressure regulator and look for any signs of gas in it. If any found then replace the FPR.
Hopefully some of the EFI experts will give an opinion soon.

 

thanks lazy k, here is some codes it pulled up
113, 116,118, 121, 126, 334, 637, 654
i did check the throttle position sensor, i have voltage to the sensor with key in the on position of about 4.9 volts. testing the sensor in ohms, as i gradually opened the throttle it went up to about 3.4 ohms with throttle 3/4 way open didn't go any higher even at full throttle so i know this sensor is bad, but i don't think its my whole problem, what do you think?

 

A malfunctioning TPS sensor will cause many transmission's problems. Also could be the VSS sensor. Do a search on the internet for 3-digit OBD1 codes. Many useful resources out there for diagnosising. If you need to replace any parts, I advise OEM/Motocraft.

EDIT: According to my Ford Code Book, you have multiple fails associated with the ECT sensor. Also IAT sensor, MAP sensor, EGR, and Transmission Overheat. I would check voltage @ all above sensor's. I agree @ no throwing money at something, when mutiple fails happen. You could be looking @ just a wiring problem, easy...or either Multiple parts have been failing for a period of time and now it's in near Failure/Limp Mode. Worst case scenario, A failing PCM.

 

Ford Fuel Injection Click on this link. From the list on the left click on TPS for testing info. From the list on the right click on 3 digit codes to get what they mean.
Also check the FPR vacuum pipe for gas.

 

Sounds like a bad 5 Volt supply in the computer.
All of the codes say they are higher then the self-test range.
I would say you have too much ripple being caused by bad caps.

 

TPS should read around .90 to .99 volts at idle and max of 5 volts at wot. O/D flashing is probably #8 fuse blown. I'll read over this again and absorb all of the codes before making further suggestions although it sounds you are loading up with fuel at idle.

 

You test the throttle position sensor voltage swing not ohms.

113 ACT sensor signal is greater than the Self-Test maximum of 4.6 volts.

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

118 ECT sensor signal is greater than the Self-Test maximum of 4.6 volts.

121 Closed throttle TPS voltage higher or lower than expected.

126 MAP/BP sensor out of self test range 1.4 to 1.6 volts.

334 DPFE or EVP circuit above the closed limit of 0.67 volts.

637 TOT sensor circuit above maximum voltage

654 MLP sensor not in park position

You seem to have a common thread there, voltage issues.

You stated you changed the neutral position sensor, based on your codes it doesn't look like you adjusted it correctly. Your statement if i put i in drive or neutral it smooths out but in park or reverse misses bad. tends to enforce that notion however you didn't state which trans you have either. Assuming E4OD?

You didn't state which test you had each code from, helpful if you include that information for those trying to assist you in the future. Looks like safe enough to assume all KOEO codes for now at least.
Keep in mind if fails KOEO test there is no point in running the KOER test, not until any and all KOEO codes are corrected first, just wanted to mention it if you weren't aware.

Anyway post what trans you have and if it is a E4OD get back under there first and properly adjust the MPLS switch. Then run the KOEO test and see what if any improvement you might see.

Oh well took to long to type it out, in the mean time others cut to the chase I see!

 

Looks like a new eec is in order.

 

it the e4od tranny, and it done the same thing before i change the neutral position sensor. how do you adjust the switch? all code test was koeo.

e4od tranny, the tranny was doing the same thing before i changed out the mpls. but how do you adjust it? also all testing was done key on engine off. thanks for the good advice

 

You have to put it in neutral loosen to two bolts stick the adjustment tool t89t-70010 in the groove tighten the bolts with it in place. Maybe some one has the image saved and will post it for you. You'll see the grove knowing what to look for, runs vertical up the center of the MLPS. You can find something fits snug in the grove easy enough, substitute for that special tool.

Anyway was just a thought, you replaced it and one code and your statements suggest you didn't adjust it correctly doing so. One code suggests you didn't have it in park for the test but surely did right?

The MLPS shares a common reference circuit with most/all the sensors you have voltage codes/issues with. If you have it set funny, the MLPS, it might just be influencing the voltages for them while in some or all its positions.

However before you changed the MLPS, why did you change it? and did you have these issues before doing so?

Ok I reread your first post,

O/D light was flashing you changed the MLPS for that only? or was the motor missing then too?

 

yes i had it in park for all testing. and in neutral for changing the mlps, it was missing od light flashing and had a code 654 manual lever position. that's why i change it, the old one probably wasn't bad.

 

A new computer should fix most if not all of the codes.

 

Yea wasn't anything you did then, time to pull the computer.

 

you really think it needs a computer? is there a way i can test it? could a used one be recommended? is it under the dash? thanks for all your help!