Progress Thread My centrifugal ppl, how’s this deal?

Sweeet . Very nice numbers . A single 70 or 76 , or an s trim would top that right off !!
Ha that’s the plan I like the V3, got a guy trying to sell me on procharger. Turbo stuff idk but possibly an option. Not a track car, just street fun and car shows etc. so want something that can give me that power now kinda deal!!
 
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Got the alignment all dialed in after the 03 cobra rack install, MM hybrid shaft and MM bump steer kit, but just waited till after the tune and dyno time was done to button it up. I’ll need to upgrade my CC plates eventually which I’ll get MM as well. Only thing needing to be finished is getting the ecu all back in its place and I’ll pick up the car this weekend. It’s been cold and raining here in Austin and the shop owner wants to get my car detailed up for me. Just excited to finally hear the car running after all the changes made. Gotta say deciding to swap out my entire exhaust brings a huge smile to my face!!!

View: https://youtu.be/uD1M07xkI90


View: https://youtu.be/XbnvZSq12uc
 
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Alrighty so here is the story. Picked up the car Saturday, super pumped! Cranked her on and it just sounds nasty. I go out and run it, and cruise around for about an hour and a half. Car stays nice and cool btw with the contour fans. Get to a buddies, he has a fox as well and we are about to head out for a drive and grab a beer. Get in and car cranks and cranks and cranks no start. Wtf!!! Try again and nothing. It’s turning like it wants to fire but won’t. Fuel pump is priming, etc so another friend shows up in his 4 eye, and has a jumper mod for the tfi module. Well by golly I get in and it fires right up. Ok so ran to autozone and picked up the tfi module or ignition control module, replace it, turns on go for a cruise and head home. Sunday morning it’s car show time. Head out, stop by a car wash, as I pull in the check engine pops on? Ok so I have the car in neutral talking with the car wash attendant, put it in 1st, gas and it dies. Try to crank and nothing. So I pushed it back out of the way. Try again and nothing. Mother F why!! So I get a ride and pick up a 30 dollar ford obd1 scanner from autozone. Does it’s thing tells me a couple of codes 15 O and 85 O but then gives me code 11 system clear. Get in and car starts right up. Ok so let it run, quick wash, 15 minutes later check engine light comes again, cars in neutral running, get in 1st gear hit the gas and dies!!! So turn it off let it sit, and check the codes again so this time I get 15 O, 85 O, 67, and 66 C I had let the car sit for a bit, got in tried to start it and it cranks on no check engine light again and I say screw I’m heading home. About a 10-15 minute drive home, pull up to the garage, check engine light again, hit the gas peddle and it dies again. Let it sit for awhile, went out it cranks on no problem and drive it in the garage. Any ideas what could be going on?
 
Take the cap off and look below the metal plate the rotor sits on. You'll see a little sensor down there. It shouldn't look powdery or soft. All the ones I've found that we're bad has some weird corrosion.... almost like battery acid on a battery post. It's easy to overlook.

It's the part the TFI module plus into inside the distributor and reads the metal piece under the rotor button.

Screenshot_20181023-165037_eBay.jpg
 
Take the cap off and look below the metal plate the rotor sits on. You'll see a little sensor down there. It shouldn't look powdery or soft. All the ones I've found that we're bad has some weird corrosion.... almost like battery acid on a battery post. It's easy to overlook.

It's the part the TFI module plus into inside the distributor and reads the metal piece under the rotor button.

Screenshot_20181023-165037_eBay.jpg
Gotcha! So why would I get code 66C which reads no Mass Air Flow sensor signal or my book with codes from the scanner states something like MAF below minimum voltage? The mass air is not brand new but new to my car. It’s a pro-m 80, which is now tucked into the fender well on an Anderson power pipe. The plug isn’t loose or anything, could said ignition pick up above have anything to do with the code at all?
 
I wouldn't think so.... but if voltsge to the computer is dropping you could get all types of weird codes. The Msf could be bad ( or the wiring connections ). I've started mustangs without the maf hooked up though. They'd run like crap but start. You could always double check where the harness was lengthened to get it into the fender.
 
I wouldn't think so.... but if voltsge to the computer is dropping you could get all types of weird codes. The Msf could be bad ( or the wiring connections ). I've started mustangs without the maf hooked up though. They'd run like crap but start. You could always double check where the harness was lengthened to get it into the fender.
Hmm so by Msf you were meaning maf right like maybe the meter is bad? Like I said it starts up and runs good, I can drive and it runs strong, but then that check engine light comes on and it will just shut down. They didn’t have any issues with it at the tune/dyno time. I’ll have to double check on the lengthening of the harnes bc that part I didn’t do and it might have been. Yeah before the tune I had everything in the engine bay, and the car ran better with the mass air unplugged after everything was done and pending the tune. Then I picked up the power pipe and had them install it for me since it was in the shop.
 
Usually, when a maf sensor goes bad it stays bad. They usually don't work sometimes and not work others. That's why I'm thinking a bad connection somewhere. That " somewhere " could realistically be anywhere between the computer itself to a circuit inside a sensor somewhere. It's very hard to diagnose intermittent problems....even harder to diagnose them online.
 
Gotcha! So why would I get code 66C which reads no Mass Air Flow sensor signal or my book with codes from the scanner states something like MAF below minimum voltage? The mass air is not brand new but new to my car. It’s a pro-m 80, which is now tucked into the fender well on an Anderson power pipe. The plug isn’t loose or anything, could said ignition pick up above have anything to do with the code at all?

Code 66 or 157 MAF below minimum test voltage.

Revised 15 mar 2018 to clarify how to do resistance checks on the MAF wiring

Insufficient or no voltage from MAF. Dirty MAF element, bad MAF, bad MAF wiring, missing power to MAF. Check for missing +12 volts on this circuit. Check the two links for a wiring diagram to help you find the red wire for computer power relay switched +12 volts. Check for 12 volts between the red and black wires on the MAF heater (usually pins A & B). while the connector is plugged into the MAF. This may require the use of a couple of safety pins to probe the MAF connector from the back side of it.

Computer wiring harness connector, wire side
71316.gif


Computer wiring harness connector, computer side side
88243.gif




Diagrams courtesy of Tmoss and Stang&2Birds

ECC Diagram for 88-90 5.0 Mustangs
88-91_5.0_EEC_Wiring_Diagram.gif


ECC Diagram for 91-93 5.0 Mustangs
91-93_5.0_EEC_Wiring_Diagram.gif


94-95 Diagram for 94-95 5.0 Mustangs[/b]
94-95_5.0_EEC_Wiring_Diagram.gif



How the MAF works

There are three parts in a MAF: the heater, the sensor element and the amplifier. The heater heats the MAF sensor element causing the resistance to increase. The amplifier buffers the MAF output signal and has a resistor that is laser trimmed to provide an output range compatible with the computer's load tables. Changes in RPM causes the airflow to increase or decrease, changing the voltage output.. The increase of air across the MAF sensor element causes it to cool, allowing more voltage to pass and telling the computer to increase the fuel flow. A decrease in airflow causes the MAF sensor element to get warmer, decreasing the voltage and reducing the fuel flow.

The MAF element is secured by 2 screws & has 1 wiring connector. To clean the element, remove it from the MAF housing and spray it down with electronic parts cleaner or non-inflammable brake parts cleaner (same stuff in a bigger can and cheaper too).

89-90 Model cars: Measure the MAF output at pins C & D on the MAF connector (dark blue/orange and tan/light blue) or at pins 50 & 9 on the computer. Be sure to measure the sensor output by measuring across the pins and not between the pins and ground.

91-95 Model cars: Measure the MAF output at pins C & D on the MAF connector light blue/red and tan/light blue) or at pins 50 & 9 on the computer. Be sure to measure the sensor output by measuring across the pins and not between the pins and ground.


At idle = approximately .6 volt
20 MPH = approximately 1.10 volt
40 MPH = approximately 1.70 volt
60 MPH = approximately 2.10 volt

Actually MAF pins C & D float with reference to ground. The signal output of the MAF is a differential amplifier setup. Pins C & D both carry the output signal, but one pin's output is inverted from the other. The difference in signal between C & D is what the computer's input circuit is looking for. The difference in the two outputs helps cancel out electrical noise generated by the ignition system and other components. Since the noise will be of the same polarity, wave shape and magnitude, the differential input of the computer electronically subtracts it from the signal. Then it passes the signal on to an Analog to Digital converter section inside the computer's CPU chip.


Check the resistance of the MAF signal wiring
For the next 2 checks make your measurement with the MAF disconnected from the wiring harness.

Pin D on the MAF wiring harness and pin 50 on the computer (dark blue/orange wire) should be less than 2 ohms. Pin C on the MAF wiring harness and pin 9 on the computer (tan/light blue wire) should be less than 2 ohms.

There should be a minimum of 10K ohms between either pin C or D on the MAF wiring connector and pins A or B.

Reconnect the MAF to the wiring harness and proceed to the next section.

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/

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel pump, alternator, ignition & A/C wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Computer,. actuator & sensor wiring
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Fuse panel layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

Vacuum routing
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
 
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Code 66 or 157 MAF below minimum test voltage.

Revised 15 mar 2018 to clarify how to do resistance checks on the MAF wiring

Insufficient or no voltage from MAF. Dirty MAF element, bad MAF, bad MAF wiring, missing power to MAF. Check for missing +12 volts on this circuit. Check the two links for a wiring diagram to help you find the red wire for computer power relay switched +12 volts. Check for 12 volts between the red and black wires on the MAF heater (usually pins A & B). while the connector is plugged into the MAF. This may require the use of a couple of safety pins to probe the MAF connector from the back side of it.

Computer wiring harness connector, wire side
71316.gif


Computer wiring harness connector, computer side side
88243.gif




Diagrams courtesy of Tmoss and Stang&2Birds

ECC Diagram for 88-90 5.0 Mustangs
88-91_5.0_EEC_Wiring_Diagram.gif


ECC Diagram for 91-93 5.0 Mustangs
91-93_5.0_EEC_Wiring_Diagram.gif


94-95 Diagram for 94-95 5.0 Mustangs[/b]
94-95_5.0_EEC_Wiring_Diagram.gif



How the MAF works

There are three parts in a MAF: the heater, the sensor element and the amplifier. The heater heats the MAF sensor element causing the resistance to increase. The amplifier buffers the MAF output signal and has a resistor that is laser trimmed to provide an output range compatible with the computer's load tables. Changes in RPM causes the airflow to increase or decrease, changing the voltage output.. The increase of air across the MAF sensor element causes it to cool, allowing more voltage to pass and telling the computer to increase the fuel flow. A decrease in airflow causes the MAF sensor element to get warmer, decreasing the voltage and reducing the fuel flow.

The MAF element is secured by 2 screws & has 1 wiring connector. To clean the element, remove it from the MAF housing and spray it down with electronic parts cleaner or non-inflammable brake parts cleaner (same stuff in a bigger can and cheaper too).

89-90 Model cars: Measure the MAF output at pins C & D on the MAF connector (dark blue/orange and tan/light blue) or at pins 50 & 9 on the computer. Be sure to measure the sensor output by measuring across the pins and not between the pins and ground.

91-95 Model cars: Measure the MAF output at pins C & D on the MAF connector light blue/red and tan/light blue) or at pins 50 & 9 on the computer. Be sure to measure the sensor output by measuring across the pins and not between the pins and ground.


At idle = approximately .6 volt
20 MPH = approximately 1.10 volt
40 MPH = approximately 1.70 volt
60 MPH = approximately 2.10 volt

Actually MAF pins C & D float with reference to ground. The signal output of the MAF is a differential amplifier setup. Pins C & D both carry the output signal, but one pin's output is inverted from the other. The difference in signal between C & D is what the computer's input circuit is looking for. The difference in the two outputs helps cancel out electrical noise generated by the ignition system and other components. Since the noise will be of the same polarity, wave shape and magnitude, the differential input of the computer electronically subtracts it from the signal. Then it passes the signal on to an Analog to Digital converter section inside the computer's CPU chip.


Check the resistance of the MAF signal wiring
For the next 2 checks make your measurement with the MAF disconnected from the wiring harness.

Pin D on the MAF wiring harness and pin 50 on the computer (dark blue/orange wire) should be less than 2 ohms. Pin C on the MAF wiring harness and pin 9 on the computer (tan/light blue wire) should be less than 2 ohms.

There should be a minimum of 10K ohms between either pin C or D on the MAF wiring connector and pins A or B.

Reconnect the MAF to the wiring harness and proceed to the next section.

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/

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel pump, alternator, ignition & A/C wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Computer,. actuator & sensor wiring
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Fuse panel layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

Vacuum routing
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
Uhhhhhhhhh yup!! That went right over my head and level of electrical now how which is basically nothing. I’m gonna send this to my buddy that might understand this way better than me and see if he can help me with this stuff. Thanks though man for this info. So say I have code 66, why can I start up the car, drive it normally but then all of a sudden the check engine light appears and it cuts off. If the mass air was bad would the car even start or even be driveable? Bc the car runs great up until that check engine light comes on. Idk just asking bc I’m clueless.
 
When the engine quits, will it restart immediately?
Have you cleared the codes to make sure you aren't seeing old codes?

How to clear codes.

Clearing the codes by pressing a button on the scan tool or disconnecting the test jumper used to start the code dump does not erase the “learned settings”. All it does is erase the stored codes in memory.

You must clear the codes anytime you replace any sensor. The following tells you how and is different from the method above

Clear the computer codes by disconnecting the battery negative terminal and turn the headlights on. Turn the headlights off and reconnect the all sensors including the MAF and anything else you may have disconnected. Then reconnect the battery negative cable.. This clears all spurious codes may have been generated while troubleshooting problems. It also clears the adaptive settings that the computer "learns" as it operates. Clearing the codes does not fix the code problems, it just gives you a clean slate to start recording what the computer sees happening.

Run the car for at least 30 minutes of driving and dump the codes again to assure that you have fixed the code problem or sensor problem. This is necessary for the computer to relearn the adaptive settings that the computer uses for proper operation. The engine may run rough at first, but should smooth out as it runs for the 15-20 minute learning period.