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2 Posts
Discussion Starter · #1 · (Edited)
Hey guys I have a 1995 ford bronco with the 5.8 or 351 Windsor and have been having nothing but issues lately. It was working fine for about a month and then it just died and will not start. It cranks and cranks but does not start. It says I have a 121 and 122 code. I just replaced the TPS, fuel pressure regulator, fuel pump, spark plugs, spark plug wires, and all the vacuum lines and it still will not start. Any ideas or information would be great. Thank you

2 Posts
Discussion Starter · #2 · (Edited)
Any help would be greatly appreciated. I do not know if it matters but is is mostly a desert truck and after hitting a whoop it started running rough and then died. I found the PCV valve had came out. It has been put back in but it still will not start

Super Moderator
29,100 Posts
Yo Andrew,
DTC 121, 122, 123, 124, 125 & P0122 and P0123 in TSB 94-26-4 "...The following is a list of vehicle symptoms which have been associated with the TPS, but can also be related to other vehicle components. Check engine light, ➡Stalls, quits, hesitation/stumble, fast idle; To minimize the replacement of good components, be advised that the following non-EEC areas may be the issue: Excessive blow-by, PCV malfunction, Vacuum leaks, Fuel pressure, Throttle sticking or linkage binding. MANY VOLTMETERS WILL AUTOMATICALLY CHANGE RANGES WHEN MEASURING TPS OUTPUT FROM IDLE TO WOT. WHEN A VOLTMETER IS USED TO MEASURE TPS OUTPUT FROM IDLE TO WOT, THE METER SCALES OR CHANGES RANGES AUTOMATICALLY. THERE MAY BE AN ERRONEOUS METER DISPLAY UNTIL THE VOLTMETER HAS LOCKED TO THE APPROPRIATE VOLTAGE READING. THE ERRONEOUS METER DISPLAY DOES NOT REPRESENT A DEFECTIVE TPS. NOTE: IT IS RECOMMENDED THAT THE "RANGE LOCK" FEATURE ON MANY METERS BE SET FOR CHECKING TPS VOLTAGE..."

●SEE Throttle Position Sensor Testing & Management @ Bronco Forum - Full Size Ford Bronco Forum by by Seattle FSB

See See my Vacuum leak test in post #11 incl jowens126 's HVAC Control Panel info @ Help with dtc codes and idle

Fuel Pressure;
Fuel Pump Circuit Operation
When the ignition is switched to the ON position, it turns the EEC Power Relay on. The EEC Power Relay provides power to the EEC-IV processor and the control side of the fuel pump relay. Power for the fuel pump is supplied through a fuse link or high current fuse attached to the starter solenoid (battery side). From the fuse link or high current fuse, current flow is through the fuel pump relay and Inertia Fuel Shutoff (IFS) switch to the fuel pump. The IFS switch is a safety device used to shut off the fuel pump in the event of a collision. If the IFS switch is "tripped," it must be reset by depressing the white or red button on the top of the switch. The fuel pump relay is controlled by the Powertrain Control Module (PCM).

When the ignition switch is turned to the ON position, the fuel pump will operate. If the ignition switch is not turned to the START position, the PCM will shut the fuel pump off after approximately one second. The PCM will operate the fuel pump when the ignition is in the START position to provide fuel while cranking.

After the engine starts, the PCM will continue to operate the fuel pump unless the engine stops, engine speed drops below 120 rpm, or the IFS switch is "tripped.

Note: Maximum fuel pressure is obtainable at WOT or the vacuum hose removed from the fuel pressure regulator.

If fuel lines/systems have been drained or evacuated, it may take up to 15 seconds to obtain the pressure specified.
System Diagnosis
Note: Grounding the FP lead at the DLC will allow the pump to run continuously with the ignition switch on.

Figure 15: Data Link Connector (DLC)

ASAP, find out if speed control recall work, if equipped was completed. If you still have concerns about Recalls, please contact the Ford Customer Relationship Center:
US: 800-392-3673 | CA: 800-565-3673
Note: 3673 spells "FORD" on phone keys
For the hearing- or speech-impaired: Please contact the Telecommunication Relay Service by dialing 71
See this guide by jowens1126 to confirm recall status @ 93 & 94-96 Cruise Control Recalls Repair
Note that the 93 recall is different than 94-96.

1995 Bronco Dealer Brochure @ 1995 Ford Bronco

1995 Bronco Drivetrain, Powertrain Service Manual - Google Drive
1995 Bronco Chassis, Service Manual - Google Drive
To switch between folder list & grid views, click the button to the right of the "DOWNLOAD ALL" button in the upper right corner of the window) by HawkDriver

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

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Premium Member
1,841 Posts
I would check the pins for the TPS and compare to what is supposed to be there. The VREF pin is supposed to have 5 volts. After my last rounds of modifications I had transmission and idle issues. After pulling codes found 122. The issue was ultimately traced to the VREF for the TPS had "displaced" itself from being fully seated in the harness. Funny thing, I had done a mass air conversion several years ago. This pin isn't relocated, but since the conversion I have not had torque converter lockup and some other slight transmission issues. My theory is it got displaced some during the conversion and finally "gave up". By your description of "is mostly a desert truck and after hitting a whoop it started running rough and then died. I found the PCV valve had came out." leads me to believe you may have a similar issue.

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