Bronco Forum - Full Size Ford Bronco Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
659 Posts
Discussion Starter #1
Greetings FSB

Second owner of 94 351 Bronco, about 210k miles.

My no run situation started after a normal start and a brief idle while loading the Bronco. The motor speed up to fast idle then died. I started with electrical, and replaced battery as the former battery did not hold charge. After numerous start attempts, hearing both fuel pump and strong starter, I tried starting fluid which resulted in normal start and idle. Was able to drive Bronco, but lacks power. Noticed check engine light on, tried unsuccessfully to pull codes with OBI both KOEO and engine running. Newly bought code reader, so still researching how to use it.

When outside temperatures permits, will perform basic tune up and have fuel filter and vacuum line kit to install. Understand importance of bringing in that trouble code. Starting fluid might be compensating for low fuel rail pressure and lack of power and a blocked fuel filter is my best case fix. Checking fuel pressure after fuel filter replaced would point me to fuel pump as next step. Will refresh my understanding of fuel pressure testing in the meantime.

Just writing to confirm if my approach is logical and if I should be looking at egr or other components if fuel system test out ok.
 

·
Super Moderator
Joined
·
25,795 Posts
Yo Tom,
Reasons for "tried unsuccessfully to pull codes with OBI both KOEO and engine running..." are;

Scan Tool Won’t Initiate Self-Test Due to Poor Grounds, Corroded Wiring, etc.; read more on how to Ground the STI & Proceed w/ Test; miesk5 Note; Steve advises; "...If the CEL is burned out, connect CEL (C) to a 12V test light, and the light's other terminal to a 12V source on the same vehicle..."
Jeremy wrote on Page 2; "...I was able to get codes the old fashioned way by counting the flashes on dashboard, so I think that would eliminate any prospect of it being something in the wiring; ....As luck would have, it appears that changing out the old EEC relay did the trick. At first I didn't think it would. Instead of using wire from the self test connector to the battery, I plugged it directly into the connector on the tool and went through the KOEO code retreival process and lo and behold I got codes..I even got the KOER test to work as well..."; miesk5 Note; Steve83 advises; "...If the CEL is burned out, connect CEL (C) to a 12V test light, and the light's other terminal to a 12V source on the same vehicle..."


Source: by Jeremy M (Big '92, jermil01) at 1992 Ford Bronco Scan Tool picture | SuperMotors.net

Scan Tool Won’t Initiate Self-Tests (solid tone only); E4OD transmission control switch wiring may be misrouted causing a short in the steering column and a blown # 17 fuse for 92-96 in TSB 92-22-5 for 92 Bronco & all Light Trucks
Source: by miesk5 at Overdrive light cycles with brake application
Electrical Systems - Multiple Malfunctions
Article No. 92-22-5 10/21/92
LIGHT TRUCK: 1992 BRONCO, F SUPER DUTY, F-150-350 SERIES
ISSUE:
The transmission control switch wiring may be misrouted causing a short in the steering column and a blown # 17 fuse. The following symptoms may be associated with this concern.
Early shifts
Loss of power
Poor acceleration
3-4 shift cycling
Transmission control light cycling ON/OFF or inoperative
Transmission control switch inoperative
Rear Anti-Lock Brake System (RABS) electronics (dash lights on, etc.) inoperative
Loss of instrumentation (tach, fuel gauge, etc.)
Unable to read Self-Test codes (solid tone only)
ACTION:
Inspect the transmission control switch wiring for damage and repair or replace as necessary. Refer to the following procedure for service details.
1. Remove the steering column cover. Refer to the 1992 Bronco/F-Series Service Manual, Section 11-04B, for the removal procedure.
2. Examine the transmission control switch wiring for damage, Figure 1. (I don't have this Figure)
3. Repair or replace the wiring as necessary.
4. Install the steering column cover. Refer to the 1992 Bronco/F-Series Service Manual, Section 11-04B, for the installation procedure.
CAUTION:
DURING REASSEMBLY, ROUTE WIRING AWAY FROM ATTACHING SCREW SO AS NOT TO PINCH OR DAMAGE WIRE.
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS:
Eligible Under Bumper To Bumper Warranty Coverage
OPERATION DESCRIPTION TIME
922205A Repair Wiring 0.6 Hrs.
DEALER CODING
BASIC PART NO. CONDITION CODE
15A808 X1
OASIS CODES:
201200, 203200, 204000, 206000, 301000, 501000, 503300, 504000, 614000, 614600
--------------------
Will look fwd to new scan tool results with baited breath😎
 

·
Registered
Joined
·
659 Posts
Discussion Starter #3
Well tripple

spray cleaned w electric cleaner test connectors, tried test no joy dang.

ran jumper wire to single wire test connector to neg bat and to frame, tried test no joy dang.

pulled 17 fuse intact and replaced, tried test no joy, dang

ECM fail??
 

·
Super Moderator
Joined
·
25,795 Posts
Yo Tom,
Inspect EEC connector for corrosion, bent or pin "back-out". If ok, yes, pull EEC.

Here are some PCM KILLER perpetrators and other causes:
Old leaky capacitors, see swapped EEC and no more codes by jowens1126
Smell around the PCM. If it smells like dead fish, it's bad.
Burned PCM printed circuit board circuits and resistors, etc.(brown burn marks).
Water damage from cowl leaks, ESPECIALLY if you you have wet carpet or mat near driver kick panel;
or on PCM Connector due to a bad hood seal near cowl panel, viewable with hood up.
Corrosion or damage due to moisture is one of the main reasons for failure. Corrosion can enter through the wiring harness and moisture can enter by a failure in the seals in the PCM itself. This happens over a period of time (5 to 10 years) due to exposure to the elements.
The alternator could be generating an AC voltage spike due to bad diode(s) or supply Voltage Overloads.
I recommend bench-testing the alternator for voltage output and AC voltage ripple.
Thermal stress due to excessive heat and excessive vibration that causes sensitive parts to fail.
Bronco was jump started on reverse polarity.

Internally
Overheated PCM.
Bad Intel 8061 chip or bad Intel 8361 memory chip
Bad Internal Voltage Regulator, see Wayback Machine by Ryan M

EEC Removal in 92-96 by bossind @ Changing out the Bronco Computer ECU
 

·
Registered
Joined
·
659 Posts
Discussion Starter #5
As always greatly appreciate FSB documentation! In final stages of gaining access to bottom EEC bracket bolt via inner fender, ran out of daylight last night. Then determine which EEC I need....

Find a old school tire shop looking for the hydraulic bumper jack they no longer use, buy it! Will lift the old Bronco with no effort.
 

·
Registered
Joined
·
659 Posts
Discussion Starter #6
Always appreciate when post are closed. So here goes...

Followed tech how to remove EEC via driver side inner fender. If your arms are long enough to reach the bottom nut on the EEC then it is possible to remove and to install by reaching down by firewall. I learned this by first attempt having EEC in wrong orientation to wiring harness. The EEC bracket has two slots that face outward while the wiring harness cover has two slides that face inward toward motor.

After several online searches where multiple EEC where shown as fitting my Bronco, I took old EEC and my VIN to part store. A day and half latter can report new part installed and no codes!
Because I had tire removed I noticed that my lug nuts could not be removed with only a tire iron. So, if tire shop installed your tires then check to ensure you can fix your next flat! I purchased shocks at a great discount some years ago so replaced quad shocks. Also noticed brake pad wear and decided to replace. And noticed that my last brake job resulted in the top brake bolt coming out! And finally, a pint of rust preventive pain on the frame sure makes the old Bronco look better!
 
1 - 6 of 6 Posts
Top