ok still backfires another new question

The MAP sensor gets connected to the manifold vacuum unless the car is converted to mass air.

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.

See http://www.troublecodes.net/Ford/
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

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.

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/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $35.

Wal-Mart may now have the LCD display scanner for less than $35


Above method to dump codes does not work:
Fix the can't dump the codes problem and your other problems may go
away as a result. The can't dump the codes problem is usually a wiring
problem that affects the signal ground for the MAP/BARO, ECT ,ACT,
TPS & EGR sensors. The same wire that acts as signal ground is the
return path for the test mode circuit.

When the computer won't go into diagnostic mode, there are usually
several other problems hiding that reduce performance considerably.

With the power off, measure the resistance between the computer
test ground (black/white wire) on the self test connector and battery
ground. You should see less than 1.5 ohms.



If that fails, remove the passenger side kick panel and
disconnect the computer connector. There is a 10 MM bolt that holds
it in place. Measure the resistance between the STI computer self
test connector (red/white wire) and pin 48 on the computer main
connector. You should see less than 1.5 ohms. More than that means a
break in the wiring .

Measure the resistance between the black/white wire on the computer test connector
and pin 46 on the computer wiring connector. You should see less than 1.5 ohms.
More than that means a break in the wiring .


Next measure the resistance between pin 48 on the computer and pins 40 & 60.
They should be less than 1.5 ohms. If it is more than 1.5 ohms, then the signal
ground inside the computer has failed. Unless you are an experienced electronic
repair technician, this means the computer needs to be replaced..

Diagram courtesy of Tmoss & Stang&2birds



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

The following is a view from the computer side of the computer connector.

noslow1986 said:

i did convert to mass air so do i need to connect the tube to the map sensor or can i plug it.

Click to expand...

The map sensor vents to the open air. Do not cap or plug it.

The vacuum line that connected it to the intake manifiold gets capped or plugged.