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JohnnyT

Help! New ecm/ecu equals new problems :-(

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Hello all. I have a 1990 bronco with a 351 and e40d. She was my daily driver with no major issues until the ecm decided to burn up one day. The number on my old one was F0TF-12A650-N2A and after much searching I found a rebuilt one at NAPA #XTP730 with the same numbers. Upon installing her, she started right up but would stumble and stall after a couple of minutes in park. I noticed the engine light is now lit all the time. She also shifts differently and stumbles/hesitates after upshfting and when I come to a stop she wants to stall. After searching the forums I decided to read the codes using the jumper method but there is no "self test input" connector under my hood that I can find. The large self test connector is there but the small input connector with the single wire is missing. Any help is appreciated. This is REALLY frustrating. Thanks.

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I don't know if this will help.

http://broncozone.co...587entry74587

 

If you follow the wires that attach to the self test connector to the wiring harness, the STI connector should come out of the harness at the same place. IIRC it is only about 6 inches from the break-out from the harness.

 

Did you remove the cover from the self test conenctor? The STI connector may be protected inside the cover.

Edited by BroncoJoe19

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I don't know if this will help.

http://broncozone.co...587entry74587

 

If you follow the wires that attach to the self test connector to the wiring harness, the STI connector should come out of the harness at the same place. IIRC it is only about 6 inches from the break-out from the harness.

 

Did you remove the cover from the self test conenctor? The STI connector may be protected inside the cover.

 

 

Thanks for the response. I pulled the cover off and the STI wasn't there (although there was the empty spot where it fits) so I figured that it was coming out of the harness and lying loose. It wasn't. Next, I unwrapped the tape covering the harness, figuring maybe the wire had been cut and I found no wire :-/ Do you know what color wire the STI has? Thanks for the input.

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Thanks for the response. I pulled the cover off and the STI wasn't there (although there was the empty spot where it fits) so I figured that it was coming out of the harness and lying loose. It wasn't. Next, I unwrapped the tape covering the harness, figuring maybe the wire had been cut and I found no wire :-/ Do you know what color wire the STI has? Thanks for the input.

 

 

BorncoJoe - I found a wiring diagram that showed the STI wire was white/pink and found the wire in the same large connector in the slot that "is not used" according to what I've read. Assuming this was the STI wire, I jumped it to the terminal directly above it (STO) and the engine light blinked the codes. I'm showing 22 - BP sensor out of test range and 85- Canister purge solenoid circuit failure according to my Haynes manual. Would these cause the symptoms I have? Thanks again.

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yo J,

 

Good job J and Broncojoe!

 

DTC 22 - Manifold Absolute Pressure (MAP)/Barometric Pressure (BARO) sensor is out of Self-Test range. Correct MAP/BARO range of measurement is typically from 1.4 to 1.6 volts.

MAP is on passsenger side firewall, high; here is one circled in blue by Jem (88 Bronco, but should be in same area)

1414197_img.jpg

Possible causes; I listed em in usual suspect line-up:

Vacuum Line is damaged.

 

Following 4 - ck connector and sensor "pins":

circuit open between sensor vehicle harness connector and PCM

circuit shorted to VREF, SIG RTN, or GND

VREF circuit open at MAP sensor

SIG RTN circuit open at MAP sensor

 

Damaged MAP/BARO sensor. It happens, I use Ford MC parts, esp for this

 

High atmospheric pressure.

 

Damaged PCM. LESS LIKELY!

-----------

The pinpoint test directs you to check the voltage to the MAP sensor. With the MAP sensor connected, use thin staright pins ( I use wife's pins that are long and have the plastic type ball @ head to help hold while attaching MM clips to the pins) to back probe the MAP connector so you make contact with the terminals inside the connector by inserting the pins into the back of the connector. This allows you to get voltage readings while the connector is plugged in.

Testing, Symptoms & Overview; "...a multimeter that can read frequency is normally required to check the sensor’s output. But you can also use an ordinary tachometer because a tach can display a frequency signal. Here’s the procedure: Connect the two jumper cables the same as before, (see diagram in site) attaching each end terminal on the sensor to its respective wire in the wiring connector. If you want to measure engine vacuum so you can correlate it to a specific frequency reading, connect a vacuum gauge to a source of manifold vacuum on the engine, or tee the gauge into the MAP sensor hose. Turn the ignition ON and note the initial reading. The reading on the tachometer should be about 454 to 464 at sea level, which corresponds to a frequency output of 152 to 155 Hz. Start the engine and check the reading again. If the MAP sensor is functioning properly, the reading should drop to about 290 to 330 on the tachometer, which corresponds to a frequency output of about 93 to 98 Hz. No change would indicate a defective sensor or leaky or plugged vacuum hose..." a vacuum gauge to a source of manifold vacuum on the engine, or tee the gauge into the MAP sensor hose. Source: by wellsmfgcorp.com .---------

map02.gif

Operational Description, pic & Parameters; MAP sensors are only used in Speed Density systems Source: by Ryan M (Fireguy50) at fordfuelinjection.com

---------------

Will post his part and add one for 85- Canister purge solenoid circuit failure

because Comcast may blink again.

Edited by miesk5

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85- Canister purge solenoid circuit failure

Overview, Failure Symptoms & Depiction, general; "...Vent fuel vapors from the carburetor bowl or fuel tank to the charcoal canister, and control the purging of these and other vapors from the fuel tank into the intake manifold when certain engine speed and temperature conditions are attained. Above idle, the mixture becomes very rich. Stumble on acceleration, poor fuel mileage, flooded charcoal canister and catalytic converter overheat can occur.

Check for ruptured diaphragms inside the valve and misrouted or damaged hoses..."

Source: by tomco-inc.com

 

Ck vacuum line between the passenger side of da engine and the vapor canister on frame rail; could have hit the exhaust manifold.

--

cprvcanp.jpg

p6130044a.jpg

Location pics in a 90 5.8

Source: by SeattleFSB (Seattle FSB) at SuperMotors.net

 

emmisions-label2.jpg

Diagram in a 90 5.8 by SeattleFSB

 

If you don't have a vac diagram on to of radiator, get a copy via;

Vehicle Emission Control Information (VECI) Decal, Vacuum Diagrams & Calibration Parts List for 88 & UP.

On-Line for Free at Ford.

Click "Quick Guides" in left panel;

Scroll to & CLICK VECI Labels "Provides Vehicle Emission Control Information (VECI) and a related calibration parts list."

Enter applicable info (need to know your Calibration number from your B-pillar sticker).

Vacuum Diagram is the same as the one on the core support or hood or air filter cover.

Source: by Ford @ http://www.motorcraftservice.com

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Jonny T,

Nice job tracking that down!

 

Here is a picture of the back end of a self test connector. Unfortunately the colors are not perfectly clear.

It looks like the STI is Yellow/pink on this beast.

 

4886d1263854888-89-f250-no-turn-sigs-then-no-gauges-now-backofselftestconnector.jpg

 

Miesk5... as always smile.gif Great job! smile.gif

Edited by BroncoJoe19

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Jonny T,

Nice job tracking that down!

 

Here is a picture of the back end of a self test connector. Unfortunately the colors are not perfectly clear.

It looks like the STI is Yellow/pink on this beast.

 

4886d1263854888-89-f250-no-turn-sigs-then-no-gauges-now-backofselftestconnector.jpg

 

Miesk5... as always smile.gif Great job! smile.gif

 

Thanks guys for all the help and encouragement. I picked up a new MAP sensor from NAPA today and will switch her out and report my findings once it stops raining. That should at least tell me if the issue is the map or the rebuilt computer having a problem communicating. The funny thing is that before my old computer started smoking, she ran fine and the check engine light wasn't on. I'm a little puzzled as to why the new one sees these faults...

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GOOD NEWS!!!!! After disconnecting the negative bat cable to clear the computer and installing the new MAP sensor things are back to normal. I let her idle for 2 minutes and then took her for a ten mile drive so the computer could re-learn things and had no issues. The engine light is now off :-) I looked for the canister purge solenoid but my truck doesn't have one that looks like the pic in that location. There is a green plastic vacuum hose that runs around to a black plastic solenoid mounted by the coil. Is there another place I should look or is this a canister purge soleniod that looks different. Thanks a TON for your help.

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yo,

 

Good to hear that on the MAP; and glad you took time to read my long and sometimes boring novels...lol

 

For that canister purge solenoid; here is a pic http://ecx.images-amazon.com/images/I/318MQM6J4NL._SL500_AA300_.jpg

Motorcraft CX1100 Vapor Canister Purge Solenoid

1990 Ford Bronco

Engine: 5.8L V8 Gas OHV Distributor-Breakerless Naturally Aspirated EFI Electronic FI MFI

 

 

maybe a prev owner removed it & plugged or re-routed lines?

 

Just in case, can you ck your Calibration Code on your driver side B-pillar sticker and either post it here or look up the; Vehicle Emission Control Information (VECI) Decal;

Contains Vacuum Diagram & Calibration Parts List for 88 & UP. On-Line for Free at Ford. Click "Quick Guides" in left panel;

Scroll to & CLICK VECI Labels "Provides Vehicle Emission Control Information (VECI) and a related calibration parts list." Enter applicable info (need to know your Calibration number from your B-pillar sticker).

Vacuum Diagram is the same as the one on the core support or hood or air filter cover.

Suggest Right Clicking this Hot Link & Open in New Window

Source: by Ford @ http://www.motorcraftservice.com

 

I cked a few already and they all show it in the diagrams

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