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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

MAF sensor or distributor modual

  • Thread starter Thread starter cj99
  • Start date Start date Sep 11, 2006

cj99

New Member
Aug 19, 2006
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0
Tonopah,AZ
Sep 11, 2006
#1
  • Sep 11, 2006
  • #1
can I check to see what the compression ratio is by using a compression gauge ? like how psi = 9.5:1 or 10:1 etc
also I am starting to have another problem. you may know by some of my past post that I was chasing a timing problem were at first the EEC was not controlling my timing and then it started to work so I reset my base timing , today 2 time while driving my car after shutting it off then getting back to goto store, it would do the missing thing again and if I put my foot into it would stop at about 3k RPM then drive normal then when I would shift it would do it again almost like a light switch when the power kick back in. some how I think the eec control is dropping in and out
I know by tracing the wire (at least I pretty sure) that the wire is good.
so its ether the EEC or the distributor ? and I had that rebuilt too but I think they just did bushing's , so is the electronic part on the
now a friend of mine had this problem years ago and it turned out to be his MAF sensor . is there a way to check this
 
T

TENGRAM

New Member
Mar 18, 2006
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0
Sep 11, 2006
#2
  • Sep 11, 2006
  • #2
you should Check for Codes. that will tell you if the MAF or any other sensor or actuator is malfunctioning. let us know what codes you get or if you need any help getting the test to work
 

cj99

New Member
Aug 19, 2006
74
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0
Tonopah,AZ
Sep 11, 2006
#3
  • Sep 11, 2006
  • #3
no code reader

TENGRAM said:
you should Check for Codes. that will tell you if the MAF or any other sensor or actuator is malfunctioning. let us know what codes you get or if you need any help getting the test to work
Click to expand...


and there is were the problem is.. i have one but ether its broke or something on the car does not like it. its old and has been put up for years. so i got it down and put a new battery in it. hooked it up to the car and i just get a steady light and beep. no codes
 

jrichker

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Sep 12, 2006
#4
  • Sep 12, 2006
  • #4
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 checks good, 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.

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.
 

cj99

New Member
Aug 19, 2006
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0
Tonopah,AZ
Sep 12, 2006
#5
  • Sep 12, 2006
  • #5
good info see if i can take it all in over the next week
thanks
 
T

TENGRAM

New Member
Mar 18, 2006
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Sep 12, 2006
#6
  • Sep 12, 2006
  • #6
cj99 said:
and there is were the problem is.. i have one but ether its broke or something on the car does not like it. its old and has been put up for years. so i got it down and put a new battery in it. hooked it up to the car and i just get a steady light and beep. no codes
Click to expand...
you don't need a code reader to read codes...only a single wire or a paperclip. check the link that i provided previously.
 

cj99

New Member
Aug 19, 2006
74
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0
Tonopah,AZ
Sep 12, 2006
#7
  • Sep 12, 2006
  • #7
ok got code reader to work.. did not have the extra wire hooked up
with engine off
8 - 1
8- 2
8- 5
9-5
engine running 4-2
3-3
thats it
 

jrichker

StangNet's favorite TOOL
In Remembrance. Thank you for your contributions
Mar 10, 2000
27,512
2,813
234
Dublin GA
Sep 13, 2006
#8
  • Sep 13, 2006
  • #8
cj99 said:
ok got code reader to work.. did not have the extra wire hooked up
with engine off
8 - 1
8- 2
8- 5
9-5
engine running 4-2
3-3
thats it
Click to expand...
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 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.

Code 82 – Secondary Air Injection Diverter Solenoid failure AM1. The dump valve air diverter valve (front vacuum operated valve) isn’t working on the Thermactor Air System (smog pump). Look for broken or missing vacuum lines on the solenoid valve to the diverter 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


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?

Most likely cause of the above codes is that someone removed the smog control equipment.


Code 95 - the following test path is for 86-90 model Mustangs.

The 95 code is because at one time or another, the fuel pump relay hiccupped and didn't provide power the pump when the computer told it to run. Sometimes this is a one time thing, other times it is a no run or runs poorly condition.

To help troubleshoot the 95 code, follow this link for a wiring diagram http://www.autozone.com/images/cds/gif/large/0900823d80167162.gif

Using the diagram, check the red/black wire from the fuel pump relay: you should see 12 volts or so. If not, check the inertia switch: on a hatch it is on the driver’s side by the taillight. Look for a black rubber plug that pops out: if you don't find it, then loosen up the plastic trim. Check for voltage on both sides of the switch. If there is voltage on both sides, then check the Pink/black wire on the fuel pump relay: it is the power feed to the fuel pump. No voltage there, check the Orange/Lt blue wire, it is the power feed to the fuel pump relay & has a fuse link in it. If there is good voltage there & at the Pink/black wire, swap the relay.

Some Mass Air conversions neglect to run the extra fuel pump wire, and they always have a 95 code. See http://www.stangnet.com/tech/maf/massairconversion.html for more information on the Mass Air wiring conversion.

Code 42 & 92 (running) System rich - Fuel control or (memory) System was rich for 15 seconds or more (no HO2S switching) - Fuel control. Look for leaking injectors, fuel pressure too high, cylinder(s) not firing due to bad ignition.

Fix this one or it will kill your gas mileage & hurt performance.

Code 33 - Insufficient EGR flow detected.
Look for vacuum leaks, cracked vacuum lines, failed EGR vacuum regulator. Check to see if you have 10” of vacuum at the EGR vacuum connection coming from the intake manifold. Look for electrical signal at the vacuum regulator solenoid valves located on the rear of the passenger side wheel well. Using a test light across the electrical connector, it should flicker as the electrical signal flickers. Remember that the computer does not source any power, but provides the ground necessary to complete the circuit. That means one side of the circuit will always be hot, and the other side will go to ground or below 1 volt as the computer switches on that circuit.
Check for resistance between the brown/lt green wire on the EGR sensor and pin 27 on the computer: you should have less than 1 ohm.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif


EGR test procedure courtesy of cjones

to check the EGR valve:
bring the engine to normal temp.
connect a vacuum pump to the EGR Valve
apply 5in vacuum to the valve.
if engine stumbled or died then EGR Valve and passage(there is a passageway through the heads and intake) are good.
if engine did NOT stumble or die then either the EGR Valve is bad and/or the passage is blocked.
if engine stumbled, connect vacuum gauge to the hose coming off of the EGR Valve
snap throttle to 2500 RPM (remember snap the throttle don't hold it there).
did the vacuum gauge show about 5in vacuum?

if not, check for manifold vacuum at the EGR vacuum valve.
if you have manifold vacuum then connect vacuum gauge to the EGR valve side of the vacuum valve and snap throttle to 2500 RPM.
should read about 5in vacuum

The operation of the EGR vacuum regulator can be checked by using a test light applied across the wiring connector. Jumper the computer into self test mode and turn the key on but do not start the engine. You will hear all the actuators (including the EVR vacuum regulator) cycle. Watch for the light to flicker: that means the computer has signaled the EGR vacuum regulator successfully.

In your case, the most likley cause of the 33 code is removal of the smog control equipment. Removal of the smog equipment on these cars can causes more performance loss than leaving it on. All of it shuts off at wide open throttle, so it doesn't hurt power. A short belt that bypasees the smog pump for track runs is a better solution.
 
C

chadjones99

New Member
Aug 19, 2006
7
0
0
Sep 13, 2006
#9
  • Sep 13, 2006
  • #9
codes

well most of that makes sence being that i have done a total smog delete
and the EGR is hooked up but no vac line going to it.
and i have been playing with the fuel pressure
so thanks for the help ! it looks like you took some time on that, and i do mean thanks
chad
 
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