MAF Guru's needed

PrplMonster · 08-31-2001, 11:31 AM

Hey guys/gals. My MAF finally took a sh*t! When i was going through the test procedures Pro-Flow describes, a few things were slightly off key..

When testing pins C & D i got 9.2-11.3vDC(bad sensor) Ok now when i test pins C & D with the key on engine off i get like 5.8vDC

Is the 5.8vDC with the KOEO supposed to be there?

I am asking these questions, because the idiot at pro-flow, told me that there wasn't supposed to be 5+/- vDC through C/D with the KOEO. Yet LaMotta perf. here in orlando says it's a VREF wire(just like the TPS has) and is supposed to have anywhere from 4-5vDC. Any idea's?

After hearing what pro-flow had to say, I untapped the ENTIRE computer harness and found no burns/breaks. ...hmm...aggrevating...

thanx much guys!
.dave

Capri306 · 08-31-2001, 02:37 PM

I'll give you the long answer just to cover all of the bases.

Pin A -- VPWR, Vehicle Power (battery)
Pin B -- PWR GND, Vehicle Power Ground
Pin C -- MAF RTN, Signal Return
Pin D -- MAF SIG, Signal to EEC-IV module

*Note: Power to the MAF sensor is controlled by the EEC-IV module; Ground is through the PWR GND circuit to the battery negative (-) terminal.

At idle, the MAF signal voltage should be approximately 0.6V.

I'd first test for power and ground by disconnecting the plug and seeing if there's at least 10.5V between A and B.

Next, with the MAF connected and the engine running (all hoses connected), backprobe the MAF connector to battery ground. You should come up with between 0.2 and 1.5V. If not, I'd consider it junk. Mebbe good time for an upgrade anyway, huh? C&L's make more (proven) power anyway.

------------------
Capri306, Moderator, The Mustang Works Online
1979 Mercury Capri, 5.0L -- C4 -- 2.73
1987 Mustang LX Notch

PrplMonster · 09-01-2001, 09:40 AM

Capri, thanx for the reply, but i have covered those bases

With the car running i get like 9-11vDC(rediculously high). I have checked the entire harness for burns/shorts and there ins't any.

If anyone out there has some time, i would appreciate you hooking up a meter between pins C & D with the key on engine off and the air meter disconnected.

I get the same reading when i use my computer or a known good one from a friends car.

any help guys..?

.dave

08-31-2001, 11:31 AM	#1
PrplMonster Registered Member Join Date: Mar 1999 Posts: 88	MAF Guru's needed Hey guys/gals. My MAF finally took a sh*t! When i was going through the test procedures Pro-Flow describes, a few things were slightly off key.. When testing pins C & D i got 9.2-11.3vDC(bad sensor) Ok now when i test pins C & D with the key on engine off i get like 5.8vDC Is the 5.8vDC with the KOEO supposed to be there? I am asking these questions, because the idiot at pro-flow, told me that there wasn't supposed to be 5+/- vDC through C/D with the KOEO. Yet LaMotta perf. here in orlando says it's a VREF wire(just like the TPS has) and is supposed to have anywhere from 4-5vDC. Any idea's? After hearing what pro-flow had to say, I untapped the ENTIRE computer harness and found no burns/breaks. ...hmm...aggrevating... thanx much guys! .dave

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Ack, amidst my motor rebuild I screwed up...(ford guru's needed!)	chickendreamer	Windsor Power	3	03-25-2003 09:02 AM
blower guru's needed asap!!!	briand	Windsor Power	1	01-03-2003 11:13 PM
Follow up to cam swap question - cam gurus needed	mysweetlx	Windsor Power	3	07-31-2002 06:56 PM
Suspension gurus needed!!!	mysweetlx	Windsor Power	2	07-09-2002 04:12 PM
Turbo gurus needed!	mysweetlx	Windsor Power	5	05-13-2002 06:22 PM

08-31-2001, 02:37 PM	#2
Capri306 Moderator Join Date: Sep 1998 Location: Grand Rapids, Michigan, USA Posts: 1,001	I'll give you the long answer just to cover all of the bases. Pin A -- VPWR, Vehicle Power (battery) Pin B -- PWR GND, Vehicle Power Ground Pin C -- MAF RTN, Signal Return Pin D -- MAF SIG, Signal to EEC-IV module Note: Power to the MAF sensor is controlled by the EEC-IV module; Ground is through the PWR GND circuit to the battery negative (-) terminal. At idle, the MAF signal voltage should be approximately 0.6V. I'd first test for power and ground by disconnecting the plug and seeing if there's at least 10.5V between A and B. Next, with the MAF connected and the engine running (all hoses connected), backprobe the MAF connector to battery ground. You should come up with between 0.2 and 1.5V. If not, I'd consider it junk. Mebbe good time for an upgrade anyway, huh? C&L's make more (proven) power anyway. ------------------ Capri306, Moderator, The Mustang Works Online* 1979 Mercury Capri, 5.0L -- C4 -- 2.73 1987 Mustang LX Notch

09-01-2001, 09:40 AM	#3
PrplMonster Registered Member Join Date: Mar 1999 Posts: 88	Capri, thanx for the reply, but i have covered those bases With the car running i get like 9-11vDC(rediculously high). I have checked the entire harness for burns/shorts and there ins't any. If anyone out there has some time, i would appreciate you hooking up a meter between pins C & D with the key on engine off and the air meter disconnected. I get the same reading when i use my computer or a known good one from a friends car. any help guys..? .dave