Engine 88 LX - Dies at highway speed fires up with key off/on rotate.

jrp27540

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Sep 9, 2016
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I have been trying to troubleshoot a issue with my car dieing randomly at highway speeds. I'm just cruising along...and then it just shuts off. All electric still works. While still flying down the road with the engine dead, if I rotate the ignition switch off then back on (not engaging the starter) the engine starts firing again with no issues. I know the injectors are still squirting gas while the motor is dead because there is an obvious strong raw fuel smell that builds up before I rotate the ignition to get it firing again. Symptoms don't sound like TFI or PIP; I changed those not long ago anyway. I'm leaning towards ignition? I only have one key on my keychain, so there isn't a lot of weight hanging on the ignition. Thoughts?
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
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Check your ignition switch under the dash on the steering column, and check the fusable links that go to your ignition, veryuseful.com can help with wiring diagrams, you should also wiggle the key switch while the car is running to see if it cuts off.
 

jrichker

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Recall on Ford Ignition switches:

Revised 7-June-2014 to add Torx bit picture and source. Also added replacement ignition switch wiring pigtail picture, part numbers and sources.

Some of the symptoms of ignition switch problems are things that don’t work or are intermittent like radio, turn signals, wipers or heater.

There was a FREE recall on Ford ignition switches. They overheat and sometimes catch fire. That burns up the steering column and sometimes the car interior. Since this is very old information, you may not be able to get the switch replaced for free anymore. The auto parts stores sell the switches for $13-$15.

4.jpg


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While you are working on the switch, check the wiring and connector closely. A replacement connector with new wiring pigtails is available from most auto parts stores

AutoZone and Advanced Auto Parts have the same Part Number: 434 - may have to order, not always in stock

Advanced Auto Parts alternate part number: PT5534



Saleen0679 was nice enough to dig this up for us awhile back: How to replace ignition switch on 1979-1993 Mustangs.
http://www.mustangandfords.com/how-to/engine/5657/


Torx bit set from Advance Auto Parts



Autocraft torx bit set – have small hole in tip for tamper proof screws.
Part No. AC571/W1386 Cost approx. $12 +tax

Diagrams courtesy of Tmoss & Stang&2birds

Ignition switch wiring
IgnitionSwitchWiring.gif


Fuel, alternator, A/C and ignition wiring
fuel-alt-links-ign-ac.gif


See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.

Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

O2 sensor wiring harness
http://www.veryuseful.com/mustang/tech/engine/images/mustangO2Harness.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pin out
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

87-92 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang87-92 PowerWindowWiring.gif

93 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang93PowerWindows.gif

Visual comparison of the Ford Fuel Injectors, picture by TMoss:
http://www.veryuseful.com/mustang/tech/engine/images/Ford_Injector_Guide.jpg
 

jrp27540

Active Member
Sep 9, 2016
173
35
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Thanks everyone. I just got a chance today to dig into it. I'm going to say this is definitely the issue... It's definitely shot as the casing has split apart and has a lot of wiggle play in it (
pic below).

I'll call this the resolution to this issue if anyone comes across this thread in the future. If the issue persists after replacing the switch, I'll let everyone know.

Thanks again for the help/advice!

IMG_20180624_153403.jpg
 
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