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Item Posts    Sort Order

Car is shutting off while driving

 
athubbard123
New User
Posts: 7
Joined: 11/13
Posted: 11/21/13 03:00 PM

Ok guys heres my problem. The other day I was driving my car, was in it prob 20 minutes. Car shut off, so I dumped my clutch to get it started. Had to do it prob 3 times in 30 seconds. Well got home took the tfi off and had it tested at the parts store. came back fine. dropped the distributor back in and started driving it again. nothing happened for 3 -4 days and today it did it again just cut off out of no where. no sigh that its gonna cut off it just does. Only loss to motor, lights, cd player.. etc all still works. Once it shuts off im able to start it rite back up, except for when the first day it started doing this the last time it cut off it took a couple minutes to get it started. Ignition coil is new new cap and button new wires and plugs. My distributor went out about 3 months ago and my buddy had one so I threw it in there and it worked fine... Please help!!!! scares me to death to drive it. im afraid when I go around a turn its gonna cut off and im gonna lose all my power steering and brakes.... No check engine light either  

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athubbard123
New User
Posts: 7
Joined: 11/13
Posted: 11/21/13 03:01 PM

oh and its a 93 5.0  

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athubbard123
New User
Posts: 7
Joined: 11/13
Posted: 11/21/13 03:05 PM

another error in my post... it only loses power to motor.. lights cd player etc stays on sorry bout that  

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athubbard123
New User
Posts: 7
Joined: 11/13
Posted: 11/21/13 05:01 PM

do people even reply on this page? 112 views and not one response.....  

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wayne712222
User
Posts: 62
Joined: 10/13
Posted: 11/21/13 05:58 PM

so many things that can cause it to just die..


i would like to have you get under the dash.. usually pulling the panel across the area above your knees.. and perhaps the lower half of the column cover and look at the ignition switch to make sure its properly working..

or just flat out replace it.. they are normally under 15 bucks and they do wear out..

they are a slight challenge to change.. but not impossible.. you normally have to knock a dent in the side of the head of the tamper proof screws.. and use that tool at an angle to start to loose the screws..  then use an 20 degree offset needle nose pliers to completely unscrew the tamper proof screw..

this allows you to get the side of the column mounted switches out without pulling the column.. or needing the special tamper proof torx bit to access it.


i have had the contacts edges burn away.. i have had the plastic electrical section separate from the zinc housing..  its spring loaded and under a lot of pressure..


got a test light... stick the PROBE end into the positive side of the coil connector .. ground the clip..  hopefully you can see this from the drivers seat or standing beside the car.. slowly rotate the ignition key from OFF to ON.. to CRANK  then back to ON.. you should not loose power..

on the TFI module... did you apply silicone dielectric grease or thermal paste to the back so it does not over heat and can transfer the heat created by the power transistor switching the coil on and off  4 times per crank revolution.  

failure at any time to have had fresh thermal paste or dielectric tune up grease behind the module will wreck the module forever..  it may work for a short while.. but it may fail..


have you replaced the EECIV main relay.. and the fuel pump relay..

they are DIFFERENT..

the EFI main relay is a conventional relay..

the EFI fuel pump relay has a diode to protect it and the ECM from a high voltage spark that will wipe it out.

i will have more later if you reply..

i cover about 10 forums.. so i don't get to every one but 3 or 4 times in 24 hours.. to see if anything is there. and today i was out and about..  

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wayne712222
User
Posts: 62
Joined: 10/13
Posted: 11/21/13 09:17 PM

please... follow the tests above... then there are more here..

189674Ba Dfbd 4746 8B76 626Dd7372e40 Zps39a79681

cleaning and tightening grounds... i have found so many mustangs and other fords that the 2 grounds on the core support where not just loose.. but the wires into the crimp terminals were almost fatigued thru.. only a few strands left is not enough.


Fordcoresupportgrounds Zps48c74c23

Fordbatterytobodygroundwire Zps74c67080

92 Mustang50dashharnesstoengine Zps6b8bd958

88Mustangefiharness Zpsd8a5c042

1995 Mustang 50Engineharness Zpsa2c34211

92 Mustang50ecmconnector Zpsbf55ea49

you might want to print this one

91 to 93 5.0..
this images below is larger than you can see..

you will see that a red and green wire comes in at the upper left and goes into the PCM power relay winding.. the other side is grounded.. this is the same circut that comes in on the right top of the image and powers the coil positive.. so that is why i want you to monitor the coil positive for power while you cycle the key thru ON, crank and back to ON without loosing power.. .

next.. key on.. see if the main relay is sending power thru to the red wire that feeds a bunch of other stuff on the fuel injection system.. the easiest one to get to is the red wire on the idle air control valve.. key on.. if the main relay is working.. you will have power at the red wire of the idle air solenoid???

thats easy..

lets look at the fuel pump circuit..

and if you find the EEC4 test connector.. one of the wires will be light blue with an orange stripe.. if you ground that wire.. the fuel pump relay should turn on..

you can then check for power to the pump via probing the wiring into the inertia switch.. where ever they stick that in that model.. but you should be able to hear the fuel flowing thru the fuel rail with the engine off..



91 93 50 EEC4 Enginecontrolwiring Zps655c81e0



every once in a while.. one runs into the 6 pin connector into the TFI module where the wires break inside the insulation..  this is a wiggle test.. wiggle the harness with the engine idling.. if the engine dies.. replace the connector and as much of the wire as the new pigtail will allow..

i think i have covered most of it..

i would also like you to perform a voltage drop test..

engine running.. headlights on..  digital meter set to 20 volts DC.

1. Negative battery post to the positive battery post... 14.1 to 14.8 volts.

2. Negative battery post to the Engine block.. 0.04 volts DC max.

3. Negative battery post to the body.. 0.02 volts DC MAX..

4. Engine block to the Body.. 0.02 volts DC max..

if you get more than these readings on tests 2, 3, and 4.. then you have loose or missing ground connections around the engine compartment.  

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wayne712222
User
Posts: 62
Joined: 10/13
Posted: 11/21/13 09:26 PM

and a slight variation.. in fuel pump control on these..

EECIV Fuelpumprelaydiagnostic Zps67d80b9d

270 Eec Fuel Pumprelayconnector Zps5cdcc7b3  

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athubbard123
New User
Posts: 7
Joined: 11/13
Posted: 11/25/13 06:13 PM

thank you for your help. im going to get out there tomorrow and mess around with it.. when I took the tfi off I could see the paste was worn off. that could be my problem?  

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wayne712222
User
Posts: 62
Joined: 10/13
Posted: 11/25/13 08:59 PM

absolutely... buy a new squeeze tube and another TFI module...

when they are thermally damaged.. they will fail again.. leaving you stranded..

if you have it tested.. have them test it six times in a row.. that is usually enough to create enough heat to make it fail if its going to fail..


Permatex/.33 oz. (9.355 g.) dielectric Tune-Up grease

   
   
 
Part Number: 81150
Alternate Part Number: 67VR
Category: Grease
Type: Dielectric

try to spread it across the middle of the TFI module plate.. so it spreads out evenly without any air bubbles.  and try not to get it on or over the mounting screw holes.. this stuff along with any other thermal grease.. becomes SAND again when exposed to heat..  or friction..  so it will lock your screws in..  and ruin your day...

radio shack also sells thermal compound..   5 to 10 bucks...

this permatex stuff works great..  

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athubbard123
New User
Posts: 7
Joined: 11/13
Posted: 11/29/13 09:04 AM

ok so I bought the new tfi and just used the compound it came with.. is that ok? do I need to take it off and get some better stuff?  

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wayne712222
User
Posts: 62
Joined: 10/13
Posted: 11/29/13 10:43 AM

what came with it will be fine..


if you have to remove it for any reason..

you have to use a fresh application of dielectric tune up grease or thermal compound.


and a TIP....

when there is a repeatable shut down failure...   use a timing light hooked over the coil wire.. the trigger on the timing light taped or rubber banded in the on position.. and the timing light placed under a wiper.. close the hood to build heat..

sit or stand with the engine at a fast idle.. or driving it around the block.. so you can push it home.. but keep an eye on the timing light flashing..

if the timing light goes out.. just as the engine dies..  but before the engine stops turning..  the ignition is failing..


if the timing light continues flashing until the engine comes to a stop.. its fuel or fuel injector related..


you might want to toss a new set of MAIN and FUEL pump relays on it anyway..

if they are original.. they are over 20 years old..

be sure to install them in the proper location..

the FUEL PUMP RELAY has a DIODE in the diagram on the side of the relay.. -|>- looks like that..

the main relay will not have that as its  only operated by the ignition key...

i would really like you to also... stick your test light into the positive or battery side of the ignition coil.. ground the clip..   slowly turn the key on.. go up and crank the engine.. and then slowly turn the key from the RUN position.. to the off.. you should NOT loose power to the ignition coil. until the key turns off.

i do this test with the starter relay solenoid wire unhooked so the engine does not start..  and i can slowly work the key thru the on.. crank and back to the ON..


being able to instantly restart it.. could be the TFI.. but it sounds more like a relay or ignition switch issue..   do you have a big ring of keys swinging from the ignition key..  

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athubbard123
New User
Posts: 7
Joined: 11/13
Posted: 12/09/13 07:46 AM

Ok so after I put on the TFI the car ran fine for about 2 weeks... Then yesterday it just shut off on me again  Mad  shut off when I got in my neighborhood. I had to dump my clutch prob 4 times just so I could get it back in the driveway..  

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wayne712222
User
Posts: 62
Joined: 10/13
Posted: 12/09/13 12:16 PM

you are going to need to follow some of my tests above..

perhaps rig some additional wires.

first one i would do is to unplug the push on connector at the starter solenoid..

stick the probe of a test light into the coil positive connector.. ground the clip.. and work the ignition key thru its cycles..  chances are the ignition switch is failing.. ..


second one.. would be the timing light on the coil wire test..  this requires driving around.. ...

third.. would be to find the inertia switch..  disconnect the connector.. hove the stripped end of some wire into the connector and plug it back in..

monitor the other end.. properly taped to a test light on the dash board..


you could have the ECM going bad..


or the main and fuel pump relays..

or a wire breaking..

we need to narrow it down

to primary ignition power as the ignition switch turns everything on..

to secondary high voltage..   no spark .. engine dies.. ..

voltage to the fuel pump...

could also be the fuel pump failing..  do you have a harbor freight store near your house????30 Amp Automotive Fuse Circuit Tester  Item #67724   this can have some wires attached with quick connects of the correct size.. the inertia switch disconnected.. and the amp meter installed..  to check the amp draw of the fuel pump..

have you checked for codes.???  sometimes they will set a code..  

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wayne712222
User
Posts: 62
Joined: 10/13
Posted: 12/09/13 12:19 PM

and.. did you run the VOLTAGE DROP TEST???



this is printable..


Voltagedroptesting  

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