Car Dies- WEIRD

Wow, you've nailed most of the things I was going to suggest. Sure sounds like the TFI. Are you spreading plenty of the heat sink paste around under the TFI module before you mount the new one ? It's really important for getting good heat transfer.

i'm the friend. the other parts replaced were ign. switch x2 fuel pump relay eec relay bypassed the inertia switch and checked for spark which i got but i beleive it was firing again so not sure if it was a good test .

You have hit all the suspect problems and replaced the high failure rate parts, so this isn't going to be easy.

Step 1.) Dump the codes. Find some, then post them here and we'll take a look to see if any of them are relevant to your current problem. Fuel pump wiring, sensors and several other systems will post codes to help pinpoint them as possible failure areas.

Step 2.) Don't find any codes, the problem is probably electrical with some loose connections: some critical part like the computer, fuel pump or TFI is losing power or signal and shutting down.
Do things like the radio, A/C or wipers, turn signals get crazy when the engine starts acting up? if so, look at the connector & wiring on the ignition switch very carefully. Tug lightly on the wires to make sure that none of them slide out of the connector shell and none of the wiring shows signs of overheating or other damage.

Step 3.) Check the wiring on the TFI modle: tug lightly on the wires to make sure that none of them slide out of the connector shell and none of the wiring shows signs of overheating or other damage.

Dumping The computer diagnostic codes on 86-95 Mustangs

Revised 19-May-2009 to update drawing for dumping the codes on 86-88 Mustangs with no check engine light.

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 way 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.

Be sure to turn off the A/C, and put the transmission in neutral when dumping the codes. Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.

Dumping the Engine Running codes: The procedure is the same, you start the engine with the test jumper in place. Be sure the A/C is off and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.

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.


WARNING!!! 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 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.

I didn't see anything mentioned in your first list about the computer itself. If the trouble shooting list by jrichker doesn't work you might try and swap out a known good computer from a similar car. Also check all of the engine grounds, especially the computer and injector grounds. Try cleaning and re-attaching the 10 pin connectors.

Removing the SPOUT causes the ignition timing to drop back to whatever was set with the SPOUT out. That is how you set the base ignition timing.

To time the ignition: remove the SPOUT and use the timing light to check the timing against the marks on the harmonic balancer. Loosen the distributor hold down bolt and turn the distributor slowly until the light and the desired mark on the harmonic balancer line up. Tighten down the distributor hold down bolt and re-install the SPOUT jumper. When you put the SPOUT back in the computer will advance the spark. The timing may move around some with the SPOUT installed.

Strype said:

Exctly what we thought. Timing is set at 14 degrees... Something is losing time and I suspect a spout connector or computer.

Click to expand...

From what I gather, the spout connector is just a jumper that you disconnect to take the computer out of the equation to set timing. So there is hardly any way it can go bad. I'd still try to borrow a like computer from a similar car and see if that helps.