!!!1990 bronco will crank but not start!!!

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Mason437

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I have a 1990 Bronco XLT 5.8. About a week ago I was driving down the road and all the sudden my engine completely shut off. I checked everything and everything looked perfect. The engine wasn't even hot yet. Out of nowhere it decided to start back up and I was able to pull it into the driveway.

It drove perfect for the next few days but come yesterday... I went outside to start it and it wouldn't. I figured it was a dead battery because over the last few days it would take a little bit longer to start each day. Brought the battery in and it was for sure dead so I bought another one.

I connected the battery and jumped in thinking my problem was fixed. I was wrong. It would crank up but no chance of starting. I am thinking the fuel pump may be trashed but I honestly don't have any experience other than reading these forums. I'm 20 and am at college so all of my dads tools are 3 hours away other than some basic tool kits I have.

I decided to check the relays just to make sure it's not a simple fix instead of having to replace the fuel pump. I opened the eec and the fuel pump relay (so the brown bottom and the green bottom) one had a little bit of corrosion in it.

I forgot to mention that when I turn the key to the in position... I can't hear anything but a faint click coming from under the hood. I also checked the inertia switch and it was like it's supposed to be. I still reset it though. I also took the fuel filter off to see if it was clogged but I could blow air pretty easily through it.

I don't have a pressure gauge or any kind of testing tools so I used jumper wires to pull codes and all I got was

81

82

96

Then it repeats over and over.

If anyone can please help... any info would be awesome.

 

miesk5

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Yo Mason437,

Welcome!

When you turn the key to the start position, does  it have a spring back to run feeling?

If not it could be a bad ignition actuatactuator pos in column thatthat actuates ignition swiswitchh at column base. Can remove column lower cover and move the actuator rod such as done in an 85; "...He turned the key on to crank (nothing happened), reached low on the column, just below the dash, and shoved his pick tool into the column and pulled down. That thing not only rolled over but it started...SO IN CONCLUSION REACH UNDER YOUR DASH AND PULL DOWN ON THAT COLUMN SWITCH ACTUATOR ROD(with the key on) AND SHE'LL LIKELY START RIGHT UP. He told me yes the switches die but they can also "walk" up the column and and get so loose the rod coming down from the key will not actuate the column switch(it's also a sign the $11 switch is about to die). He also recommended I change that *** metal actuator rod assembly (Ford # E9TZ*3E715*B, $16.32 CDN). This took him half an hour and if I'd been able to do it I estimate even after my install lesson would have taken me most of the day..." 

Source: by Sixlitre (Malcolm H, Eddie Bauer) 

...

Great job on checking for Codes!!!

DTC 96 koeo & CM, Fuel pump secondary circuit failure. The EEC did not sense battery voltage on the Fuel Pump Monitor circuit. Fuel Pump circuit failure, battery to processor;

To test fuel pump try this Fuel Pump Test & Diagram at the Diagnostic Link Connector in 84-95; "...Connect FP Relay to any ground to force the fuel pump(s) on when the key is in RUN...". dlc-eeciv.jpg

...

Long or no crank- Inspect for loose battery posts, connectors, cables and visible wire strands & under insulation an inch or so under coonectors:

- for corrosion, damage or looseness.
- include ground cables from battery post & connector to engine, frame, intake manifold, hood, etc.; 
- and positive cable from battery to relay to starter.
 

check starter relay body to inner fender for tightness to a clean, non-rusted/grime -free surface

Inspect for loose battery posts, connectors, cables and visible wire strands & under insulation an inch or so under coonectors:
- for corrosion, damage or looseness.
- include ground cables from battery post & connector to engine, frame, intake manifold, hood, etc.; 
- and positive cable from battery to relay to starter.
- check starter relay body to inner fender for tightness to a clean, non-rusted/grime -free surface

Check voltage @ FP relay & pump

Fuel Pump Relay Wiring Diagram in a 90 

1990-bronco-fpr-and-eec-relay.jpg

Source: by Seattle FSB

or try :

 http://easyautodiagnostics.com/ford/4.9L-5.0L-5.8L/fuel-pump-relay-tests-1

http://easyautodiagnostics.com/ford/4.9L-5.0L-5.8L/eec-power-relay-tests-1

http://troubleshootmyvehicle.com/ford/4.9L-5.0L-5.8L/how-to-troubleshoot-a-no-start-1

For some of the tools/test devices, check with local parts stores for a loan a tool program, refundable deposit for such as:
Fuel Pump Diagnostic Kit, spark tester ...
http://www.autozone.com/

..

Codes 81/and 82 will not cause your no start issue; they indicate voltage output for secondary air injection solenoid did not change when activated. Possible causes for this fault are:

• AIRB/AIRD (TAB & TAD circuit(s) shorted or open. 
• Fault in solenoid or PCM.
Location pic in a 90 5.8; 
tab-tad-evr-coil2a.jpg
"...the Yellow Vacuum Line goes from the TAD Solenoid (driver's side forward solenoid) to the TAD (Diverter) Valve located at the rear of the Intake Manifold. You have to climb up onto the engine to feel the Diverter Valve or remove the Intake Manifold..The Pink Vacuum Line goes from the TAB Solenoid (driver's side rear solenoid) to the passenger side (adjacent to the Vacuum Reservoir Can) and down to the bottom of the TAB (Bypass) Valve.." 
Source: by Seattle FSB (SeattleFSB) 

Disconnect both solenoid connectors. Turn ignition on. Measure voltage between VPWR terminal (RED WIRE in wiring diagram below) of wiring harness connector and battery ground for both solenoids. If either voltage reading is less than 10.5 volts, repair wiring harness open circuit, and repeat QUICK TEST. If both readings are 10.5 volts or more, go to step 9).

9)Measure Solenoid Resistance :
Turn ignition off. Leave solenoid connectors disconnected. Measure resistance of both solenoids. If either reading is not 50-100 ohms, replace solenoid assembly and repeat QUICK TEST. If both readings are 50-100 ohms, go to step 10).

10) Check Circuit Continuity :
Leave ignition off. Disconnect PCM 60-pin connector. Inspect terminals, and repair if damaged. Install EEC-IV Breakout Box

instead of Box, go to PCM connector PIN
eec04.gif

EEC IV PCM Connector Pin Depiction Pic by Ryan M (Fireguy50) @ eec04.gif
And ÈEC IV Pin Legend @ http://web.archive.org/web/20120118104425/http://www.oldfuelinjection.com/truckpinouts.html

leaving PCM disconnected. Measure resistance between AIRB test pin (PCM PIN 51) and AIRB terminal at wiring harness connector. Measure resistance between AIRD PCM PIN 11) test pin and AIRD terminal at wiring harness connector. If either reading is 5 ohms or more, repair open circuit and repeat QUICK TEST. If both readings are less than 5 ohms, go to step 11).

11) Check For Short To Ground :
Leave ignition off and solenoids disconnected. Measure resistance between test pin No. 51 and test pins No. 40, 46 and 60 at breakout box. Measure resistance between test pin No. 11 and test pins No. 40, 46 and 60. If any reading is less than 10,000 ohms, repair short to ground and repeat QUICK TEST. If all readings are 10,000 ohms or more, go to step 12).

12) Check For Short To Power Circuit :
Turn ignition off. Measure resistance between test pin No. 51 and test pins No. 37 and 57 at break-out box. Measure resistance between test pin No. 11 and test pins No. 37 and 57 at breakout box. If any resistance is less than 10,000 ohms, repair short to power and repeat QUICK TEST. If code is repeated, replace PCM. If all resistances are 10,000 ohms or more, replace PCM and repeat QUICK TEST.

Wiring Diagram in a 90 
1990-bronco-eec-schematic.jpg
Source: by SeattleFSB (Seattle FSBFSB)...

...

1990 Bronco Pre-Delivery Shop & Electrical & Vacuum Troubleshooting Manual  (EVTM), Partial by Kingfish Google Drive @ https://drive.google.com/drive/mobile/folders/0BzRTW4yeT2u4UkhzR0ZydDd3MzA?usp=sharing&tid=0BzRTW4yeT2u4NXB6NW5neFRoZGc

Slow to scroll, so I get a drink and Find page # of item desired in contents, then flip screen flip down like spinning a bearing then stoping perioically to see what page you are now on.

 

miesk5

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Yo,

Will be back after 4:00 PM EDST until ~ 7:00 PM.

Then back Thursday around lunch time off and on [SIZE=23.9997px]until ~ 7:00 PM.[/SIZE]

[SIZE=23.9997px]Friday through next week from 8 AM until 7P M[/SIZE]

 
OP
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Mason437

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I will for sure go rent the tools from Autozone right now and do the tests. Thank you for all the info.

I pulled the FP Relay off and it has a rattle when you shake it. I've heard that means it's for sure broken. Any advice? Either way I am going to buy a new relay just invade.

Thanks!

 

miesk5

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Yo,

Good!

I recommend just Ford Motorcraft relays.  Other brands are iffy.

Spring back is good!  Means actuator i ign switch are good.

 
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Mason437

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So I put the new FP relay on there and have it a shot but no difference. Should I replace the eec relay too or do you think it's just a bad fuel pump? Autozone doesn't rent the tool out so I'm going to another parts store.

 
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Mason437

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I read on here about people jumping their fuel pump to make sure it works. I've yet to find out how they do this. I read that all you need is a piece of wire? I mayb be completely wrong. I just really don't have the money to blow on a new pump IF that's not the problem.

 

miesk5

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Yo,

Here is the test..I posted it in my first reply:

To test fuel pump try this Fuel Pump Test & Diagram at the Diagnostic Link Connector in 84-95; "...Connect FP Relay to any ground to force the fuel pump(s) on when the key is in RUN...".

dlc-eeciv.jpg

You can replace EEC IV RELAY.

 
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Mason437

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Okay I did the test and all that happened was a lot of clicking in my new FP relay

 

miesk5

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Yo,

Inspect wiring to EEC & FP Relay connectors.

Esp the Red wires at both.

Background;

When the ignition switch is turned ON, the Electronic Engine Control (EEC) power relay is energized, providing power to the fuel pump relay for 1 to 2 seconds through the Powertrain Control Module (PCM) and an Inertia Fuel Shutoff (IFS) switch. 

Fuel pump power is provided through the fuel pump relay contacts, if the PCM does not receive an ignition signal within approximately one second after the ignition switch is turned to the "ON" position. A timer circuit in the PCM will open the ground circuit to the fuel pump relay, causing the fuel pump relay contacts to OPEN. This action stops the power supply to the fuel pump. 

When the ignition switch is turned to the "START" position, the PCM closes the ground circuit to the fuel pump relay, resuming operation of the fuel pump.

After the ignition switch is returned to the "ON" position, power to the fuel pump is supplied through the fuel pump relay. 

The PCM monitors engine speed and opens the fuel pump relay ground circuit if the engine speed drops below 120 rpm.

...

Have a doc appointment.

Bb after lunch time.

 

miesk5

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Yo,

Can you check the circuit using the wiring diagram?

DTC 96 means a fuel pump secondary circuit failure....secondary circuitis the on/off circuit in the relay that supplies the 12-vdc voltage to the pump and is monitored by the Fuel Pump Monitor (FPM) pin or signal at the ECM pin 19.

bronco_1991_49-2.gif

http://troubleshootmyvehicle.com/ford/4.9L-5.0L-5.8L/fuel-pump-circuit-tests-1

Test to see if voltage is getting to the fuel pump secondary circuit through the inertia switch and FP relay after the engine has been turned off

Lightly tap the relayS, if power is still being supplied through the relayS

No Start, or Low State of Battery Charge or Buzzing or Humming Noise from the Fuel Pump after the Engine has been Shut Off Caused by Sticking Fuel Pump Relay TSB 90-18-3 by Ford

1983-1990 CROWN VICTORIA, ******, EXP, MUSTANG, TEMPO, THUNDERBIRD
1986 LTD
1986-1990 TAURUS
1983-1990 BRONCO IIBRONCO, ECONOLINE, F-150F-250F-350, RANGER
1988-1990 F SUPER DUTY
LINCOLN: 1983-1990 CONTINENTAL, MARK VII, TOWN CAR
MERCURY: 1983-1987 LYNX
1983-1990 COUGAR, GRAND MARQUIS, TOPAZ
1985-1986 CAPRI, MARQUIS
1986-1990 SABLE
ISSUE OTHER APPLICABLE ARTICLES: None
A “buzzing” or “humming” noise from the fuel pump may occur after the engine has been shut off. There may also be a no start condition or a discharged battery. These conditions are caused by a sticking fuel pump relay. Install a new fuel pump relay. Refer to the following procedure for service details. 
1. Check the fuel pump relay circuit for proper operation. Refer to the appropriate EVTM for troubleshooting details.
2. Install a new fuel pump relay, if the old one is defective.
3. Check the vehicle for proper operation.

 

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