1990 Bronco XLT 5.8l

[racrx]

So 1990 Bronco XLT 5.8l. new to me, it was sitting for a few years. I cleaned the throttle body, changed out the TPS, map and IAC. Vehicle runs very well but it has no acceleration under load< cant get out of my own way. Checked codes KEEO got a 32, 63. and 67. I believe code 32 is for the egr, code 63 is a memory code which is for the TPS and code 67 also memory code is for the NSS. The first TPS i installed was bad out of the box, replaced. check engine light was on but after replacing the TPS for the second time it is now off. I checked the timing and it was off so i put it at 10 degrees. Still getting the same codes.

The OD off lamp stays lit all the time. Would you get transmission code in KOEO test mode? Any suggestions would be appreciated.

I haven't changed the NSS yet but have the part. It has to be re-pinned.

 

[miesk5]

Yo racrx,
Welcome!
The OD light comes on when you turn OD off. so the light is letting you know you need to turn it back on.
OD is on by default every time you start up your Bronco.

DTC:
32

JOwens has an easier EGR test, "all you really need is a piece of vacuum tube. remove egr valve, attach vacuum line, **** on the open end, look at the bottom of the egr valve to make sure the pintle moves and hold vacuum on the line to make sure it doesnt leak down and close. thats pretty much all you need to do there. You can clean the insides up with brake kleen to get all the gunk out of it. It will make it move alot easier."

Next up to bat is EGR Valve and EGR Position (EVP) Sensor Testing & Replacement @ EGR Valve Position (EVP) Sensor Testing & Replacement
by Seattle FSB

63
KOEO TPS circuit below minimum 0.6 volts.
CM TPS circuit has intermittently failed below minimum 0.6 volts

and 67
MLPS Test by Mikey350 @ http://www.fullsizebronco.com/forum/7-1980-96-bronco-tech/405778-very-high-idle-pulled-codes.html
●
Here are the 1990 Bronco Pre-Delivery Shop, Emission and Electrical & Vacuum Troubleshooting Manuals (EVTM), Partial by member Kingfish999 in Google Drive @ 1990 Ford Truck service manuals - Google Drive
&
1990 Ford Truck Emissions Manual.pdf by Ford via member 90.CaliBronco in Google Drive @ 1990 Ford Truck Emissions Manual.pdf
Suggest you download both for faster scrolling and to use the table of contents index.

1990 Ford Bronco Brochure by Ford via Dezo's Garage @ https://www.xr793.com/wp-content/uploads/2020/07/1990-Ford-Bronco.pdf

Haynes Red Manual for 80-95 Bronco & F Series @ Hanes guide 80-96 bko f series.pdf found by BroncMom!

See my mostly recovered View attachment 202203
site by schwim @ Ford Bronco And F-150 Links - FORD BRONCO

Iggie BOO INFO, MY ERROR
Be well racrx!
Al

 

[miesk5]

Also, my tablet is mixing up info such as the BOO.

 

[racrx]

Also, my tablet is mixing up info such as the BOO.
View attachment 30665View attachment 30666

Thanks for the response. The od off light doesn't go off at all. Pressing it in and out has no effect. I will run the EGR tests. My biggest concern is that the engine runs good and goes into gear no problem, but the is very little acceleration. Would the egr cause this condition?

 

[miesk5]

Yo racrx,
See Table 12 below on Left Side;

Ignore Scope Engine for now to save your $
Quick Test is the Diagnostic Trouble Code Test
Check Fuel Pressure & IAC port in throttle body.for gunk.
View attachment 193621
●See my Vacuum leak test in post #11 includes jowens1126 HVAC Control Panel info @ Help with dtc codes and idle

 

[racrx]

Yo racrx,
See Table 12 below on Left Side;
View attachment 30667
Ignore Scope Engine for now to save your $
Quick Test is the Diagnostic Trouble Code Test
Check Fuel Pressure & IAC port in throttle body.for gunk.
View attachment 193621
●See my Vacuum leak test in post #11 includes jowens1126 HVAC Control Panel info @ Help with dtc codes and idle

thanks. back to work then will try these steps

 

[Motech]

Code 67 will set during On-Demand KOEO test (not continuous) if:

1. AC switch turned on, or
2. Incorrect voltage at AT Shift Lever Position sensior during self test

First, disregard EGR codes. Most have miscalibrated EVP sensor from factory, will always set that code but never trigger light or symptoms.

TPS code might be memory, it it might be reading lower voltage than old one. Memory reset will clear that.

My recommendation:

First erase Keep Alive Memory with a 30minute battery disconnect.
Then fire up engine and, if doable, take a quick spin around the block.

Upon return, shut it down, make sure HVAC controls are shut completely off and run KOEO Self-Test again.

Disregarded EGR codes.
If TPS code returns, that will need to be diagnosed.
If 67 comes back, you now know your problem is with the shift selector sensor, commonly called the Park/Reverse/Neutral/Drive/Lo sensor(PRNDL, or prindle)
A problem here can and will cause your OD Off lamp to stay in AND your gutless power output too. It will need to be diagnosed and repaired.

Unlike earlier eighties models, 1990 EEC IV controllers do display sensor values with a scan tool capable of Ford scanability. This will make your job SO MUCH easier, so borrow one if possible.

 

[Motech]

the time. Would you get transmission code in KOEO test mode?

Yes. AT controls are included within PCM. In fact, that's why it is called PCM, or powertrain control module, including AT compared to ECM, engine-only control module.

All EEC IV systems with 2 digit codes generate AT codes beginning with 6, as in 67.

 

[Motech]

Heck, since you already have one, if 67 and OD Off light return after above steps, pin and replace that sensor, reset KAM again with extended battery disconnect and try it again!

 

[racrx]

Heck, since you already have one, if 67 and OD Off light return after above steps, pin and replace that sensor, reset KAM again with extended battery disconnect and try it again!

thanks for the feedback. appreciate it

 

[racrx]

I plan on swapping out the MLPS sensor tomorrow. The new sensor came with no directions. Is it just a pin for pin swap?

 

[Motech]

I plan on swapping out the MLPS sensor tomorrow. The new sensor came with no directions. Is it just a pin for pin swap?

The pin I spoke of is alignment installation pin. Comes with replacement and locks rotating sensor in place for installation with transmission in NEUTRAL.

A drill bit is commonly used too.




PROCEDURES

EXCEPT AOD TRANSMISSION

1. Disconnect battery ground cable.
2. Remove downshift linkage rod return spring from low-reverse servo cover.
3. Apply penetrating oil to outer lever attaching nut, then remove transmission downshift outer lever attaching nut and lever.
4. Remove neutral safety switch attaching bolts, then disconnect electrical connectors and remove switch from vehicle.
5. To install, position switch on transmission and secure with attaching bolts. Do not tighten bolts at this time.
6. Place transmission manual lever in neutral position, then insert a .091 inch gauge pin through gauge pin holes, Fig. 4.
7. Tighten switch attaching bolts, then remove gauge pin.
8. Install outer downshift lever and retaining nut.
9. Install downshift linkage rod return spring between lever and retaining clip on low-reverse servo cover.
10. Reconnect electrical connectors, then check operation of switch.

AOD TRANSMISSION

1. Disconnect battery ground cable.
2. Raise and support vehicle.
3. Disconnect electrical connector at neutral safety switch, lifting connector straight up.
4. Using suitable socket, remove neutral safety switch and O-ring seal.
5. Reverse procedure to install, installing new O-ring seal.

 

[racrx]

i have a newer switch so i have to repin the connector to the new one. im assuming since no directions were included that the pin sequence is the same. so i should just detach a pin and attach in same position on new switch? thx for responding so quick!

 

[racrx]

So now i decided to check my fuel pressure at the schrader valve. i have no reading at all. i jumped the fuel pump and still no pressure. the pressure gauge is a rental from the auto parts store. im pretty sure it works because i got a reading that was leas than 5. is there one fuel pump on a 1990 bronco 5.8l or two. ive looked and im not seeing the second one? weird part is with very little pressure the vehicle still starts and idles????

 

[miesk5]

Yo racrx,
Your 90 has a single, high pressure pump which is part of the modular, In-Tank Reservoir (ITR) assembly. Besides the pump, the ITR consists of a venturi jet pump, a supply check valve and a shuttle selector valve. All this is mounted on the fuel gauge sender ******. The sending unit is separate from the ITR module.

Ask family members or friends if they have a similar fuel injected vehicle with the Schrader valve.

 

[goodO1boydws]

So 1990 Bronco XLT 5.8l. new to me, it was sitting for a few years. I cleaned the throttle body, changed out the TPS, map and IAC. Vehicle runs very well but it has no acceleration under load< cant get out of my own way.

Unless I missed it, you didn't mention getting rid of the old gas.
Old gas loses octane-which lowers performance.
(And can compromise filters and injectors.)

 

[chrlsful]

2 Qs if any 1 is willing. I could C it as a thread jack, but I will go nowhere further w/answ: When did OBDI come in? Was it only "the counting the flashes system"? (nothing B4 or after that? I wuz not there when it went from DSII to OBDII) Was B4 and after. Thank you.

 

[Tiha]

OBD I has been around as long as fuel injection. So mid 80's? You could get hand held scanners that would do a little more, like run self diagnostics, but yeah for the most part it displayed a number for the error code or you counted the flashes.

OBD II came in 1995? I think.

Before OBD I you had some electronic carbs, electronic ignitions but no ECM to run it all. For the Dura spark system there was a test kit that would run self diagnostics but it usually didn't work because they system only acted up when the ignition module was hot.

Or at least it was something like that.

 

[miesk5]

Yo,
Electronic Engine Control History, Ford;
1978: "...Ford Motor Company introduces its first Electronic Engine Control (EEC-I) system. This system was very limited in the control of engine functions and only controlled ignition timing, EGR flow and the air pump's injection of air into the exhaust.
1979: Ford introduces the EEC-II system. This system added air/fuel ratio control (feedback carburetor), throttle kicker (controls engine idle speed during start up and AC function) and canister purge control to the ECC-I system.
1980: Ford introduces the EEC-III system. This system included all the sensors used by the ECC-II system, with the addition of a temperature Sensor.
In 1981, the ECC-III system was modified to include controls for the new Electronic Fuel Injection systems. The EEC-III system was used on some models of Ford vehicles until 1984.
1980: In addition to the EEC-III system, Ford introduced another computer control system, called the Microprocessor Control Unit (MCU). This system was used on a limited number of Ford vehicles up until 1991.
1983: Ford introduces the Electronic Engine Control - IV (EEC-IV) system. This system is capable of controlling a larger number of sensors, switches and actuators, and was used on a greater number of Ford vehicles. The ECC-IV system was used from 1983 to 1995. 1994:

Ford introduced the EEC-V system (OBD-II). This is a highly sophisticated system that uses more special programs to enhance the computer's capability to monitor, detect and report failures, especially to the vehicle's emission system. This system was introduced on a limited number of 1994 and 1995 vehicles. Starting in 1996, all Ford vehicles (cars and light trucks) sold in the US are equipped with the EEC-V system..."

 

[King Daddy Rabbit]

So 1990 Bronco XLT 5.8l. new to me, it was sitting for a few years. I cleaned the throttle body, changed out the TPS, map and IAC. Vehicle runs very well but it has no acceleration under load< cant get out of my own way. Checked codes KEEO got a 32, 63. and 67. I believe code 32 is for the egr, code 63 is a memory code which is for the TPS and code 67 also memory code is for the NSS. The first TPS i installed was bad out of the box, replaced. check engine light was on but after replacing the TPS for the second time it is now off. I checked the timing and it was off so i put it at 10 degrees. Still getting the same codes.

The OD off lamp stays lit all the time. Would you get transmission code in KOEO test mode? Any suggestions would be appreciated.

I haven't changed the NSS yet but have the part. It has to be re-pinned.