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1990 code help

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#1 greyhound


    Duck Tape L'fixer :)

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Posted 12 February 2010 - 06:56 PM

I have a 1990 ford f-150 with a 5.8 motor and e4od tranny 2 wheel drive.I put my code meter on the truck and had a code 26 and a second code 67.My book said the map sensor was out of sinc.I replaced that a year ago.Also code 67 said that neutral shifting indicator switch on the tranny was the problem,changed that a year ago also.After that I had no codes showing.My book is no help in what to look for and how to fix these two codes.Thanks Rick FROM OHIOEmail me

#2 miesk5


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Posted 14 February 2010 - 09:30 AM

One poss is that the NSS (or also called the MLPS) was ok...or connector was/is bad/corroded; or AC was left on, or transmission was in gear during the Self Test..........

DTC 67 Neutral Drive Switch (NDS) Circuit Open; "...In some cases all of us at one time or another have had to "jiggle' the column shifter to get the vehicle to start because over time things losen up from DD useage.....in the Haynes Manual transmission section and www.broncolinks.com there's a diagram referring to "Point A" which is the column shift linkage and the transmission tab. A sure way to correct the "jiggling" is to go underneath the BKO on the drivers side and LOSEN the "nut" on column shift linkage and tranny tab JUST ENOUGH to click the tranny tab all the way back until it stops then 2 clicks forward and tighten the "nut".....now the column shift linkage and transmission are in sync when you go thru the grears, assuming the steering column is in resonable condition this should help correct that problem.......TOO MANY TIMES THE NSS IS DEEMED THE CULPRIT for none start when it isn't so this is a simple check to make sure. There is also another PRNDDL adjustment, but you need to remove the black plastic collar on the steering wheel, this is usually done when an actuator breaks and using pliers drive the rod downward with key on to start.....there is usually a white cable that wraps around and attached to a small mm screw IIRC that when lossened a bit it allows you to adjust the "needle" that registers on each letter of the PRNDDL..be careful because it's attached with a very fine wire loop and easily broken. The "upper ignition actuator" is another culprit because they're made of cheap pot metal.....and a PITA job to do..." by JKossarides

DTC 67 & DTC 634; "E4OD Nagging Neutral Nonsense & Pinpoint Test, Manual Manual Lever Position (MLPS) also called Transmission Range (TR) Sensor. Some of the problems the MLPS can cause are wrong gear starts, TCC hunting, no 4th gear, engine stalling, high or erratic line pressure & a sudden neutral condition; The negative lead of the multimeter should be placed at the MLPS signal-return ground terminal at the MLPS..." Source: by Pete L at transonline.com
Water Intrusion of Manual Lever Position (MLPS) also called Transmission Range (TR) Sensor TSB 95-2-12 for 89-94; Some vehicles may exhibit a shift concern and/or a harsh engagement concern due to water intrusion into the MLP/TR sensor and vehicle harness. There may also be a number of different DTC's along with those concerns Source: by Ford via miesk5 (Al M) at comcast.net

MAF Operational Description, pic & Parameters (click on Sensors) Source: by Ryan M (Fireguy50) at fordfuelinjection.com
26 (or): MAF (Mass Air Flow) signal out of range. Suspect sensor and/or connector and harness, check both to see if they are really dirty.

Troubleshooting & Operation, Bronco & Ford Source: by sensorland.com

MAF Sensor (Mass Air Sensor) also known as NSS

The MAF is one of the most important sensors in your engine, it is composed by 2 elements, the housing and the meter. The housing is a 3"+ aluminum cylindrical element that sits inside the air filter housing. On top of the housing sits the meter, it is a small black box that contains 2 thin heated wires (when on). Those wires change their resistance as air flow cools them down and the resulting voltage is sent to the EEC to tell it how much air is flowing, the EEC then will adjust injector pulse to change fuel delivery.

One of the most common MAF failures is caused by DIRT that passed through the air filter. If you use a stock air filter, the time it would take for the sensor wires to gather enough dust to fail would be long. But in the case of aftermarket OILED filters such as a K&N it will take a short time if the filter is over-oiled.

So if you have a K&N that has been cleaned and re-oiled, let it sit for a while to let the excess oil drip, then clean it with a lint free cloth.

A contaminated Maf sensor can be diagnosed by several symptoms:

LEAN CONDITION, displayed as KOER codes from the O2 sensors
Backed-up timing, a result of the lean condition in which the EEC will back timing to reduce chance of detonation
Low TOP END power, as a result of reduced timing and fuel.
So what can you do to remedy this?

The answer is simple, remove the MAF housing from the air box. At the top of it remove the 2 retaining tamper proof Torx Bit screws and GENTLY pull the sensor out. If the 2 filaments of the sensor are dirty (dark in color) clean them with a Qtip until all contaminants are removed. Check the Maf wiring harness for loose or dirty connectors and bad wiring.

Reinstall and test your car.

You will instantly feel a GREAT difference in horsepower, probably as much as 30hp are lost when the MAF fails by contamination.
by allfordmustangs.com

Did you do both Tests?Do this, a Self Test by BroncoJoe19 do the KOEO = Key On Engine Off portion first & Remember to have engine @ Normal Operating Temperature before doing the KEY ON ENGINE RUNNING (KOER) portion

DTC 26, 56, 66, or 76 (part ad) - Mass Air Flow (MAF) Failure Symptoms, Bronco by CARDONE® cardone.com

Edited by miesk5, 14 February 2010 - 10:02 AM.

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