87 LX stang sputter 3500 up RPM

It is a symptom of one mode of TFI failure. However, the situation will often worsen in a short period of time.

Though wires are new, being sure they are really well separated isnt a bad idea. It also could be a PIP issue. Look inside the bowl for metal shavings (or run a magnet down there to see if it picks up ferrous materials). Spray down the PIP with electrical contact cleaner and see if the issue improves.

Good luck.

It is unlikely that your fuel injectors are causing the problem you describe.

There is no need to remove the distributor to replace the TFI. You may need a special socket to loosen the screws. Most auto parts stores will carry the socket if you need it.

You should only have to loosen distributor and rotate it enough to get to get the module off. Be sure to pull it down to free the connections on the top kof the module. Mark where the distributor was positioned and realign and time it after new one is on. It also helps to have it unplugged prior rotating it. I am just going by what I remember from my old car My Cobra is mounted on the fender.

Don't install the TFI module if you bought it from anywhere other than ford.
Chain store ones have been known to not last long, and some even are DOA.

Uhhhh, didn't think to ask late last night:

What flavor of plugs do you run? If platinums, swap them out for Autolite or Motorcraft copper plugs and the issue may very well go away.

Cool. If it pops back up, swap the plugs. Platinum doesnt conduct as well as copper, ergo some folks have a funky idle and a ~3500-4000 RPM cut-out/miss with plats.

Glad to hear you got it.

Don't replace the MAP sensor if it does not set a code. You could be spending $65 for nothing.

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 http://www.troublecodes.net/Ford/





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.



89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.



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.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 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 http://www.midwayautosupply.com/pc-7208-90-equus-digital-ford-code-reader-3145.aspx – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

Code 22 MAP (vacuum) or BARO signal out of range. The MAP or BARO sensor is pretty much the same sensor for both Mass Air & Speed Density cars. The main difference is where it is connected. Mass Air cars vent it to the atmosphere, while Speed Density cars connect it to the intake manifold vacuum. Its purpose is to help set a baseline for the air/fuel mixture by sensing changes in barometric pressure. The MAP or BAP sensor puts out a 5 volt square wave that changes frequency with variations in atmospheric pressure. The base is 154 HZ at 29.92" of mercury - dry sunny day at sea level, about 68-72 degrees. You need an oscilloscope or frequency meter to measure it. There is no way you can use a common cheap voltmeter or DVM to accurately measure the output signal.

The MAP/BARO sensor is mounted on the firewall behind the upper manifold.

Baro or MAP test using frequency meter - run the test key on engine off. The noise from the ignition system will likely upset the frequency meter. I used a 10 x oscilloscope probe connected from the frequency meter to the MAP/BAP to reduce the jitter in the meter's readout.

If it is defective, your air/fuel ratio will be off and the car’s performance & emissions will suffer

Some basic checks you can make to be sure that the sensor is getting power & ground:
Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter.
Check the resistance between the black/white wire on the MAP/BARO sensor and then the black/white wire on the EGR and the same wire on the TPS. It should be less than 1 ohm. Next check the resistance between the black/white wire and the negative battery cable. It should be less than 1.5 ohm.

The following power on check requires you to turn the ignition switch to the Run position.
Use a DVM to check for 5 volts on the orange/white wire. If it is missing, look for +5 volts at the orange/white wire on the TPS or EGR sensors. Use the black/white wire for the ground for the DVM.

DominickS said:

Ok this is off topic but to you jrichker or anyone else that knows

I replaced my 95 F-150 EEC computer with a EEC from a 95 mustang
code is W4H0 now my truck did not have a MAP/BARO sensor so now that I have the
mustangs EEC should I put one in and wire it into the EECs harness??

Click to expand...

The W4 EEC internally takes care of the BAP correction (there is no separate sensor).