my car is really pissing me off every part is new from heads up well mods in sig i have 24 lb fms injectors with a 76mm c&l meter but i don't know if i have the right mas sensor on top of it or the right map sensor because the car did not have them on it when i got it ! does anybody with a 90 gt have part numbers for map and mas sensor's also what is your base fuel pressure vac off . thanks !
My cars running rich and wont idle ?
- Thread starter 89lxcoupe
- Start date
txstang84
15 Year Member
First off, if your car is a '90 it won't have a MAP sensor, it'll be a BARO, or BAP sensor. It mounts in the same place as the MAP sensor in the SD cars, but the BAP sensor doesn't hook up to manifold vacuum like a MAP...all it measures is ambient barometric pressure, whereas a MAP sensor measures engine vacuum (also translated as engine load to the ecu).
As far as part numbers, I can't remember the one for a MAP or BAP, but for the factory 89-93 Mustang MAF, I think it's something like: E9ZF-12A679, or F1ZF-12A679...something like that. All you really need to confirm is the first four digits (E9ZF, or F1ZF)...unless you're using a Cobra computer (X3Z) in which case, the MAF should say F2VF. (edit
It's possible you have the wrong sample tube for the MAF and injectors...? Ck the C&L website to make sure. If you're using an A9L, with 24lb injectors, I think the sample tube needs to be blue.
About FP though, if you're only using a fairly small cam, just set your pressure to 40 and go from there. You can also ck the sticky for "surging idle cklist"
As far as part numbers, I can't remember the one for a MAP or BAP, but for the factory 89-93 Mustang MAF, I think it's something like: E9ZF-12A679, or F1ZF-12A679...something like that. All you really need to confirm is the first four digits (E9ZF, or F1ZF)...unless you're using a Cobra computer (X3Z) in which case, the MAF should say F2VF. (edit
It's possible you have the wrong sample tube for the MAF and injectors...? Ck the C&L website to make sure. If you're using an A9L, with 24lb injectors, I think the sample tube needs to be blue.About FP though, if you're only using a fairly small cam, just set your pressure to 40 and go from there. You can also ck the sticky for "surging idle cklist"
its a 90 gt with a9l computer yeah i meant bap sensor, the one i have on there now might have come off my old 88 sd coupe i can't remember yea there no vaccum going to it. also i have the blue sample tube thats supossed to be for 24 lb inj ? still confused...... when i bought the car the map,bap plug was cut off so i went and cut one from a wrecked car when i got home i noticed that one of the wires didn't match one of them in the harness so i just tied it to the one that was left ! don't know if that has anything to do with it !
Measure out the diameter of the sample tube, on both ends. Then compare your dimensions to those listed on the C&L page on my site.
C&L doesn't provide the diameters, but they have been known to mis mark a sample tube before.
It is best to confirm with the diameter...
You need to use the factory MAS sensor on the C&L meter. By that I mean factory sensor for the A9L computer.
It sounds like you need to confirm some wiring on the BAP sensor too.
Ford did make some wiring harness changes through the fox years, so it would be easy to get screwed up.
Also, pulliing your codes could give some good info.
I have a link in my sig if you don't have a scanner.
Hope that helps.
jason
C&L doesn't provide the diameters, but they have been known to mis mark a sample tube before.
It is best to confirm with the diameter...
You need to use the factory MAS sensor on the C&L meter. By that I mean factory sensor for the A9L computer.
It sounds like you need to confirm some wiring on the BAP sensor too.
Ford did make some wiring harness changes through the fox years, so it would be easy to get screwed up.
Also, pulliing your codes could give some good info.
I have a link in my sig if you don't have a scanner.
Hope that helps.
jason
Codes? this post is useless without codes...
Dump the codes and see what the computer says is wrong… Codes can be present without setting the Check Engine Light.
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 Walmart.
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.
Dump the codes and see what the computer says is wrong… Codes can be present without setting the Check Engine Light.
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 Walmart.
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.
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 cablet. 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.
Code 34 Or 334 - EGR voltage above closed limit - Failed sensor, carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the flange side of the EGR by mouth. If it leaks, there is carbon stuck on the pintle valve seat, replace the EGR valve ($85-$95).
If the blow by test passes, and you have replaced the sensor, then you have electrical ground problems. 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 post. It should be less than 1 ohm.
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.
Let’s put on our Inspector Gadget propeller head beanies and think about how this works:
The EGR sensor is a variable resistor with ground on one leg and Vref (5 volts) on the other. Its’ resistance ranges from 4000 to 5500 Ohms measured between Vref & ground, depending on the sensor. The center connection of the variable resistor is the slider that moves in response to the amount of vacuum applied. The slider has some minimum value of resistance greater than 100 ohms so that the computer always sees a voltage present at its’ input. If the value was 0 ohms, there would be no voltage output. Then the computer would not be able to distinguish between a properly functioning sensor and one that had a broken wire or bad connection. The EGR I have in hand reads 700 Ohms between the slider (EPV) and ground (SIG RTN) at rest with no vacuum applied. The EGR valve or sensor may cause the voltage to be above closed limits due to the manufacturing tolerances that cause the EGR sensor to rest at a higher position than it should.
This will affect idle quality by diluting the intake air charge
Code 67 - clutch not depressed (5 speed) or car not in neutral or park (auto) or A/C in On position when codes where dumped. Possible neutral safety switch or wiring problem. This code may prevent you from running the Key On Engine On tests. You can generally ignore this code, since it has no effect on engine performance.
Code 81 – Secondary Air Injection Diverter Solenoid failure AM2. The solenoid valve located on the back side of the passenger side wheel well is not functional. Possible bad wiring, bad connections, missing or defective solenoid valve. Check the solenoid valve for +12 volts at the Red wire and look for the Lt Green/Black wire to switch from +12 volts to 1 volt or less. The computer controls the valve by providing a ground path on the LT Green/Black wire for the solenoid valve.
With the with the ignition on, look for 12 volts on the red wire on the solenoid connector. No 12 volts and you have wiring problems.
With the engine running, stick a safety pin in the LT Green/Black wire for the solenoid valve & ground it. That should turn the solenoid on and cause air to flow out the port that goes to the pipe connected to the cats. If it doesn't, the valve is bad. If it does cause the airflow to switch, the computer or wiring going to the computer is not signaling the solenoid valve to open.
Putting the computer into self test mode will cause the solenoid valve to toggle. If you listen carefully, you may hear it change states.
Code 82 – Secondary Air Injection Diverter Solenoid failure AM1. Possible bad wiring, bad connections, missing or defective solenoid valve. Check the solenoid valve for +12 volts at the Red wire and look for the Red/White wire to switch from +12 volts to 1 volt or less. The computer controls the valve by providing a ground path on the Red/White wire for the solenoid valve
With the engine running, stick a safety pin in the Red/White wire for the solenoid valve & ground it. That should turn the solenoid on and cause air to flow out the port that goes to the pipe connected to the heads. If it doesn't, the valve is bad. If it does cause the airflow to switch, the computer or wiring going to the computer is not signaling the solenoid valve to open.
Code 84 - EGR Vacuum Regulator - Solenoids. The EGR vacuum regulator solenoid is inop, missing vacuum, broken vacuum lines, vacuum leaks, or bad electrical wiring from the computer or no power to the solenoid.
Code 85 - CANP solenoid - The Carbon Canister solenoid is inoperative. Check vacuum lines for leaks and cracks. Check electrical wiring for loose connections, damaged wiring and insulation. Check solenoid valve operation by grounding the gray/yellow wire to the solenoid and blowing through it.
The computer provides the ground for the solenoid. The red wire to the solenoid is always energized any time the ignition switch is in the run position.
Charcoal canister plumbing - one 3/8" tube from the bottom of the upper manifold to the rubber hose. Rubber hose connects to one side of the canister solenoid valve. Other side of the solenoid valve connects to one side of the canister. The other side of the canister connects to a rubber hose that connects to a line that goes all the way back to the gas tank. There is an electrical connector coming from the passenger side injector harness near #1 injector that plugs into the canister solenoid valve. It's purpose is to vent the gas tank. The solenoid valve opens at cruse to provide some extra fuel.
It does not weigh but a pound or so and helps richen up the cruse mixture. It draws no HP & keeps the car from smelling like gasoline in a closed garage. So with all these good things and no bad ones, why not hook it up & use it?
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 cablet. 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.
Code 34 Or 334 - EGR voltage above closed limit - Failed sensor, carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the flange side of the EGR by mouth. If it leaks, there is carbon stuck on the pintle valve seat, replace the EGR valve ($85-$95).
If the blow by test passes, and you have replaced the sensor, then you have electrical ground problems. 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 post. It should be less than 1 ohm.
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.
Let’s put on our Inspector Gadget propeller head beanies and think about how this works:
The EGR sensor is a variable resistor with ground on one leg and Vref (5 volts) on the other. Its’ resistance ranges from 4000 to 5500 Ohms measured between Vref & ground, depending on the sensor. The center connection of the variable resistor is the slider that moves in response to the amount of vacuum applied. The slider has some minimum value of resistance greater than 100 ohms so that the computer always sees a voltage present at its’ input. If the value was 0 ohms, there would be no voltage output. Then the computer would not be able to distinguish between a properly functioning sensor and one that had a broken wire or bad connection. The EGR I have in hand reads 700 Ohms between the slider (EPV) and ground (SIG RTN) at rest with no vacuum applied. The EGR valve or sensor may cause the voltage to be above closed limits due to the manufacturing tolerances that cause the EGR sensor to rest at a higher position than it should.
This will affect idle quality by diluting the intake air charge
Code 67 - clutch not depressed (5 speed) or car not in neutral or park (auto) or A/C in On position when codes where dumped. Possible neutral safety switch or wiring problem. This code may prevent you from running the Key On Engine On tests. You can generally ignore this code, since it has no effect on engine performance.
Code 81 – Secondary Air Injection Diverter Solenoid failure AM2. The solenoid valve located on the back side of the passenger side wheel well is not functional. Possible bad wiring, bad connections, missing or defective solenoid valve. Check the solenoid valve for +12 volts at the Red wire and look for the Lt Green/Black wire to switch from +12 volts to 1 volt or less. The computer controls the valve by providing a ground path on the LT Green/Black wire for the solenoid valve.
With the with the ignition on, look for 12 volts on the red wire on the solenoid connector. No 12 volts and you have wiring problems.
With the engine running, stick a safety pin in the LT Green/Black wire for the solenoid valve & ground it. That should turn the solenoid on and cause air to flow out the port that goes to the pipe connected to the cats. If it doesn't, the valve is bad. If it does cause the airflow to switch, the computer or wiring going to the computer is not signaling the solenoid valve to open.
Putting the computer into self test mode will cause the solenoid valve to toggle. If you listen carefully, you may hear it change states.
Code 82 – Secondary Air Injection Diverter Solenoid failure AM1. Possible bad wiring, bad connections, missing or defective solenoid valve. Check the solenoid valve for +12 volts at the Red wire and look for the Red/White wire to switch from +12 volts to 1 volt or less. The computer controls the valve by providing a ground path on the Red/White wire for the solenoid valve
With the engine running, stick a safety pin in the Red/White wire for the solenoid valve & ground it. That should turn the solenoid on and cause air to flow out the port that goes to the pipe connected to the heads. If it doesn't, the valve is bad. If it does cause the airflow to switch, the computer or wiring going to the computer is not signaling the solenoid valve to open.
Code 84 - EGR Vacuum Regulator - Solenoids. The EGR vacuum regulator solenoid is inop, missing vacuum, broken vacuum lines, vacuum leaks, or bad electrical wiring from the computer or no power to the solenoid.
Code 85 - CANP solenoid - The Carbon Canister solenoid is inoperative. Check vacuum lines for leaks and cracks. Check electrical wiring for loose connections, damaged wiring and insulation. Check solenoid valve operation by grounding the gray/yellow wire to the solenoid and blowing through it.
The computer provides the ground for the solenoid. The red wire to the solenoid is always energized any time the ignition switch is in the run position.
Charcoal canister plumbing - one 3/8" tube from the bottom of the upper manifold to the rubber hose. Rubber hose connects to one side of the canister solenoid valve. Other side of the solenoid valve connects to one side of the canister. The other side of the canister connects to a rubber hose that connects to a line that goes all the way back to the gas tank. There is an electrical connector coming from the passenger side injector harness near #1 injector that plugs into the canister solenoid valve. It's purpose is to vent the gas tank. The solenoid valve opens at cruse to provide some extra fuel.
It does not weigh but a pound or so and helps richen up the cruse mixture. It draws no HP & keeps the car from smelling like gasoline in a closed garage. So with all these good things and no bad ones, why not hook it up & use it?
Similar threads
