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#1 Rjet

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Posted 28 October 2012 - 05:59 AM

Hey, new to the forum, early thanks to all that can help.. I have a 1993 Bronco, 5.8, Stock vehicle. Last night it died, No Spark, No Fuel pressure. I've ck'd the most common (what I thought was common) areas. Fuel pump, Fuel relay, Roll over switch, Battery voltage, etc... I did find that the fuel pump relay is not latching, I can manually close it to make the pump run, But without the spark, fuel will do me no good.. When turning the Key on, I can hear a few relays clicking under the hood, but could not tell you which ones. Is it common on these for the PCM to cook, My son did say he thought.. he smelled some electrical burning, but I could not find any evidence of burning. I did try to see if there was a spark from the coil, when turning the engine over, no spark, until you release the key, I get one hit only. It will do this everytime. I replaced the coil, no help. I do have batt voltage at the coil. Would the TFI have anything to do with controlling the fuel also, or is it controlled by the PCM? Have not tried to pull codes. I just downloaded the code sheets and how to pull them. Ill get these later if anyone needs them to help trbl shoot this.

Thanks...

#2 miesk5

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Posted 28 October 2012 - 08:26 AM

yo RJET,

Welcome!
A quick Relay test for both Fuel Pump & EEC Power Relays is to Swap relay w/Horn Relay & try to start - as long as Horn does honk



Operational Sequence, Depiction & Wiring Diagram in 92-95; "...Operational Sequence: 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 high current MAXI fuse ). Current flow is then 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.

If the ignition switch is not turned to the START position, the EEC-IV 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: Grounding the FP lead at the DLC will allow the pump to run continuously with the ignition switch on.

MIESK5 NOTE; from Ford EVTM; The Control Module (PCM) runs the pump for one second when it receives an ignition- on signal. It also runs the pump as long as it receives a PIP signal from the Hall-effect devices (inside the Distributor), it continues pump operation even after the key is released from START. If the PIP signals fall below 120RPM, the control module cuts off the signal to the fuel pump relay. MIESK5 Note, The PCM then opens the fuel pump relay ground circuit. The pump will also run when the terminals of the fuel pump test connector are jumped. the Control module signals the pump when it receives a CRANK signal, and when the Control module gets PIP signals that the engine is running. the pump does not run if the PIP indicates the engine is not running even with ignition ON {except for that first one second}. (MIESK5 Note, A timer circuit in the PCM will open the ground circuit to the fuel pump relay, causing the fuel pump relay contacts to OPEN)..." READ MORE http://www.thediesel...ra/vra09001.htm

Power Distribution Box Diagram in a 93 Bronco & F Series
Source: by Steve83
Posted Image


No Start Troubleshooting but Starter Cranks Engine in 4.9, 5.0, or 5.8L; "....TIP 1: Since a lot of folks confuse a No Crank Condition with a No Start Condition... I'll clear it up right now: In a No Start Condition means your vehicle's Starter Motor is cranking the Engine but the Engine is not starting. In a No Crank Condition, the Engine is not cranking when you turn the key to crank the Engine. This article only deals with a No Start Condition..." read more
Source: @ http://troubleshootm..._no_start_1.php

EXCERPTS:
•Test the PIP Sensor..
◦The PIP Signal is at the heart of the Ignition System and it triggers the Ignition Control Module to start activating the Ignition Coil.
◦The PIP Signal is also used by the PCM to start injecting Fuel into the Cylinders.
◦You can test the PIP Sensor on your Ford vehicle.
◦You can find the PIP Sensor Test here (the test is bundled in with how to test the Ignition Control Module):
◦Distributor Mounted Ignition Control Module Test ◦Fender Mounted Ignition Control Module Test

in my archived BRONCO TECHNICAL

site; http://web.archive.o...s.com/index.php?;
select a LINK, Right Click and and Hit Properties;

copy the second HTTP address

paste in a new browser to see the original page

96 Bronco, E4OD, Man Xfer Case & Hubs
Thanks to All Who Serve


#3 miesk5

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Posted 28 October 2012 - 10:39 AM

yo, also
If the fuel pump relay kicks on when cranking, the TFI & Stator are good..."
Source: by Ryan M (Fireguy50) at http://oldfuelinjection.com/?p=12

in my archived BRONCO TECHNICAL

site; http://web.archive.o...s.com/index.php?;
select a LINK, Right Click and and Hit Properties;

copy the second HTTP address

paste in a new browser to see the original page

96 Bronco, E4OD, Man Xfer Case & Hubs
Thanks to All Who Serve


#4 Rjet

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Posted 28 October 2012 - 11:08 AM

Thank you for the info.. Here is another issue. I went home for lunch and tried to pull the codes. Grounded out the connetors and fuel pump kicked on and now will not shut off. (Prior to this it would not even come on) Even with the shorting wire removed from the connector. As soon as you turn on the key the pump runs continuesly. It still will not start. I ckd for spark again, no spark.. If i Disconnect the Spout conn, it will backfire but not start. My son is going to pick me up a TFI module and try it while im here at work. I can smell electrical burn under the dash where the module is. Its a faint smell but nonetheless its there. I can not get any codes from the computer, everytime I try the pump just runs and runs, and never gets to codes. I would like to try the PCM, but alas, they are special order everywhere here in Louisville. Am I going down the correct path?

#5 90bronco86

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Posted 28 October 2012 - 09:43 PM

Thank you for the info.. Here is another issue. I went home for lunch and tried to pull the codes. Grounded out the connetors and fuel pump kicked on and now will not shut off. (Prior to this it would not even come on) Even with the shorting wire removed from the connector. As soon as you turn on the key the pump runs continuesly. It still will not start. I ckd for spark again, no spark.. If i Disconnect the Spout conn, it will backfire but not start. My son is going to pick me up a TFI module and try it while im here at work. I can smell electrical burn under the dash where the module is. Its a faint smell but nonetheless its there. I can not get any codes from the computer, everytime I try the pump just runs and runs, and never gets to codes. I would like to try the PCM, but alas, they are special order everywhere here in Louisville. Am I going down the correct path?

I had the exact same problem on my 90, for me it was the ignition control module, its located on the side of the distributur its not too hard to check, u have to loosen the distributor (make sure to mark it and double check it with a timing gun after your done, i believe its supposed to be set at 12 degrees) then rotate it till you can get a rachet in there, you will need either an inverted torx bit or in my case an deep well thin walled 5.5 socket, theen you can take it to any parts store and they can test it for you.
1990 bronco Edie Bauer 5.8 351 stock besides 33 12.50 15 all Terrains

1986 bronco xlt 5.0 302 stock besides 33 12.50 15 thornbirds and a chopped exhaust. (sold) will miss greatly!

#6 Rjet

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Posted 29 October 2012 - 03:53 AM

Thats what Im Going after next, We took the TFI to a Local shop and they tested it, Worked fine. The PIP module is next. Miesk5 had sent in his post above some really good info on Trbl shooting the modules. I went thru the sites he sent , they contain a world of info... They went as far as showing you how to make the test rigs. I will get to this week as I am working for the next few days. Thanks to all for the info. I will post the test results...

#7 miesk5

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Posted 29 October 2012 - 04:05 AM

yo,
The TFI Ignition Module is located below driver side hood hinge.

The Control Module (PCM) is located inside cab, drivers side below dash
Control Module (PCM) Location pic by Dustin S (Dustball, Mellow Yellow, Mr. Laser Boy) @ http://ylobronc.user...llclearance.jpg
from under the hood; un-bolt the 10 mm bolt recessed in the center of its connector, set the connector aside, remove the 2 11mm nuts (above & below), then pull the PCM & its weather seal straight forward into the engine bay. It may be necessary to bend the plastic wheel well liner to make room.
If this PCM is smoking, most likely it's capacitors are leaking, PCM ckt board is shorted to caase as reported by BroncoJoe or more.

A timer circuit in the PCM will open the ground circuit to the fuel pump relay, causing the fuel pump relay contacts to OPEN; if PCM is burnt & inop now, the timer circuit will not open the FP relay and pump will continue to run


FAILURE, PCM, Capacitor Repair: "... finally pulled the computer and
Source: by dolittle (seedpress) at Ford Bronco Zone Forums http://broncozone.co...livery-problem/



Could be FP relay is stuck closed
Did you Swap w/horn relay & try again?
( - as long as Horn does honk)
same for EEC relay
or,


do accessories (radio, etc.) turn on when turning key to accessory or run positions? if not; The ign switch actuator and or switch needs to be adjusted

in my archived BRONCO TECHNICAL

site; http://web.archive.o...s.com/index.php?;
select a LINK, Right Click and and Hit Properties;

copy the second HTTP address

paste in a new browser to see the original page

96 Bronco, E4OD, Man Xfer Case & Hubs
Thanks to All Who Serve


#8 Rjet

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Posted 29 October 2012 - 08:14 AM

I ck'd the relay's. The fuel pump relay is not stuck, I did do the swap as you suggested. Right now the pump stays on all the time, Like you mentioned, as if the PCM timer has gone out. But I still have no spark. According to the Links you sent me Ive tested all the componants up to the PIP module in the Dist. They said this is what creates the spark to get the ball rolling.. Then once the PIP senses 120 rpm the PCM takes control. The moudle is only 19.00 at the store, (not the zone) so I am just going to replace it and try. If this does not fix it, then the last part is the PCM. All other avenues have been exhusted.. Ill post the results.. Thanks for the info....

#9 Rjet

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Posted 31 October 2012 - 02:06 PM

Got it going..... Ater following the well put advice of all the members on the forum, I ended up having to change the PIP module, and the computer. The comp fried the PIP. I uploaded a pic of the inside of the comp. Toast.... And believe it or not, the local Oriellys had one in stock for 83.00 THANK YOU TO ALL WHO HELP ME GET THIS GOING, THIS SITE IS AWESOME....

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