I'm having some sort of electrical stall in my 87 Mustang GT. The car will buck and hesistate, and other times just stall completely. The car will do this whether the throttle is engaged or not. The RPMS will flux and the car will just die. No sputter, just a shut off. If the car dies, I can usually start it right back up and it will be fine the rest of the day. I replaced the Ignition Control Module and Ignition Coil and the car has a brand new battery and new plugs, wires, cap and rotor. I ripped off the steering column and checked all the wiring. I'm thinking it might be my alternator. I noticed that my alternator is reading a steady 14 volts, but occassionally will drop to 11 and shoot right back to 14. Today, the car stalled going down a hill. It bucked once and my volts dropped to 11, there was a loud grinding noise from the right front of the engine bay, and the car died. I rolled to a stop, fired her up, and drove 30 miles to work with no problems. I've had a couple people say the MAF sensor is bad, but just to debunk that theory, my car is not a MAF conversion, and to any fuel starvation issue theories, the car never sputters, it just cuts. This is definitely electrical. I had my alternator tested and according to the non-mechanic manning the machine "everything looks fine." I have my doubts about that test, but I'd rather not throw money into an alternator when it might be something as small as a bad ground. Any advice?
87 Mustang Stall problem
- Thread starter ChaosXIW
- Start date
Does any other electrical accessories such as heater fan, radio or turn signals malfunction at the same time? If so replace the ignition switch.
No other concurrent malfunctions? Dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.
Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
See Troublcodes.net Trouble Codes OBD & OBD2 Trouble Codes and Technical info & Tool Store. By BAT Auto Technical
If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.
What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems.
Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.
Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.
Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.
Or for a nicer scanner see EQUUS DIGITAL FORD CODE READER (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.
No other concurrent malfunctions? Dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.
Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
See Troublcodes.net Trouble Codes OBD & OBD2 Trouble Codes and Technical info & Tool Store. By BAT Auto Technical
If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.
What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems.
Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.
Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.
Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.
Or for a nicer scanner see EQUUS DIGITAL FORD CODE READER (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.
Thanks, i'll take a look. To your question about the other electronics malfunctioning, I have an aftermarket stereo, and the head unit reboots every time I experience a surge. I was thinking it was the ignition switch, cylinder, or alternator. I'll replace the switch today and see how it does, since the switch is WAY cheaper than the alternator. The only problem is my car only stalls or surges once every couple days, so it may be a while before I know if thats the problem. Is there any way to test the ignition switch once it's out so I know it's fried?
On another note, when I experience the power failure, I lose power steering and brakes as well. After some research it's my understanding that the ignition switch maintains power supply to power steering and brakes as well. I think, and hope, that you're onto something here, because electrical system issues are irritating to solve.
Fellas, make like the Dallas Cowboys and get along for sixty minutes please? Santa is a friend of mine, he's just being a chode. Thanks for sticking up for me though, he can be an ass. Paz, I hear you, so i'm thinking my alternator is starting to wear down, resulting in the loss of the volts. However, the ignition switch, the little box under the steering column, not the actual cylinder, was badly worn and stock from 1987. It's separated from the contacts, which would definitely cause my sudden stall. The loss of volts is probably an indicator that my alternator is due to be changed in the future, but if the way my car runs now is any indicator, the alternator was not the root of my stalling problem. Time will tell. Thanks
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