HELP! 50lb injector trouble.

STOCK LX · 09-17-2001, 08:08 PM

Help. I have 50lb injectors and a bullet 75mm MAF. I am getting a check engine light with a code 66 low MAF voltage. Is this because the 50lb's are so big that the voltage signal to the computer is below the low limit? Is there any way to correct this? Maybe with a different meter? The MAF has just been recalibrated, so that isn't it.
Thanks.

PKRWUD · 09-17-2001, 09:12 PM

Your injectors have nothing to do with it. A code 66 is caused by one of the following:
Open MAF circuit
Open VPWR circuit to MAF sensor
Open PWR GND circuit to MAF sensor
MAF circuit shorted to ground
Faulty ECM or MAF sensor
Air leak before or after MAF sensor
MAF sensor disconnected

Start checking!

Take care
~Chris

------------------
Retired Moderator
MustangNet

My site: JimPorterRacing

RACECAR spelled backwards is RACECAR

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Unit 5302 · 09-17-2001, 10:18 PM

The real question is, why in the world are you running 50lb injectors that can support 1000hp on a 75mm MAF sensor?

STOCK LX · 09-17-2001, 11:06 PM

I have an ATI procharger, and I thought since it is a blow through it didn't need such a big meter.
Also, the car runs fine with the stock MAF, and injectors, no light at all. So I don't think it is in the wiring.

Unit 5302 · 09-18-2001, 06:00 PM

Just as an FYI the ProM 75mm Bullit has had calibration problems with the 24lb injectors, this could be what you are experiancing with the 50lbers.

How many hp are you going to be pushing?

STOCK LX · 09-20-2001, 11:42 AM

I don't know how much power. I can't dyno it yet, because it won't take full throttle!! It is a 393 with 8.5 to 1 comp. So I am thinking 500+? Also I think I found the problem, the MAF is only putting out .1 to .2 volts at idle. So I think the meter is defective.

09-20-2001, 01:08 PM

You're WAY over injected. Eve with the procharger, on a stock engine, 36#ers would've been more than enough. Not that that's the problem, just an observation.

------------------
'90 LX 5.0;12K original miles (no sh*&);3.55 gears; March pulleys;Edelbrock Performer Heads;BBK 1 5/8" equal length shorties;MSD 6AL ignition w/ blaster 2 coil;FMS E303 cam;Pro-M 75mm MAF;BBK 70mm TB; Eibach drag-launch spring kit;Southside welded subs;9" K&N cone filter charger;Hurst shifter;Cervini's 3" turbo hood;A/C delete; gutted cats;2 chamber Flomasters;Corbeau racing seats;FMS 30# injectors;JMS chip; Holley 190lb fp;TFS track heat Intake (12.299 @ 113 - 1.78 60')

302 LX Eric · 09-20-2001, 01:14 PM

Did you get the blow-thru type meter from Pro-M? The blow-thru type has a rim on each end of the meter to help keep the air tubes from blowing off in boost situations.

Also, a properly built 393 with any decent amount of intercooled boost should produce some serious HP. Like in the area of around 650 HP!

Keep us posted on your ride - sounds like one mean "STOCK LX."

I'm curious about the details of your combo - would you mind providing some details?

Also, IMHO, your injector size is just fine. A 393 stroker with a big huffer and high flowing heads, et al calls for some serious fuel demands.

Take care, E

------------------
1991 5.0 LX Coupe - 38,000 miles

13.17 @ 106.14 mph w/ 2.138 60'

[This message has been edited by 302 LX Eric (edited 09-20-2001).]

09-20-2001, 01:34 PM

Quote:

Originally posted by bada$$lx:
You're WAY over injected. Eve with the procharger, on a stock engine, 36#ers would've been more than enough. Not that that's the problem, just an observation.

I think U need to read his last message or so. He might be under injected depending on how much boost he is running.

------------------
Black SN95
TFS heads, Holley intake, AFM B-2 cam,
12.9 @110mph best ET
13.06 @111mph best MPH After gutting out clogged cats and a much better tune. Took Nitrous out for warranty work

didn't have time to put back in for track.

Unit 5302 · 09-20-2001, 07:33 PM

Under injected? Not unless he's making over 900hp, and that would take some SERIOUS boost.

302 LX Eric · 09-21-2001, 08:02 AM

FYI (and FWIW), LaRocca's runs 50# injectors on several of their ProCharged 302/306s. I spoke to Jimmmy LaRocca a couple times regarding injector size about 9 months ago for my coupe. I too was skeptical of the large injector size, but Jimmy insisted on no less than 42's for my combo - and actually encouraged me to go with 50's. His expertise on ProCharged Mustangs is very extensive. I am no fuel system guru, just lending my observations.

And, again, a properly built 393 w/ adequate cfm from a blower will make some serious HP. I sure wouldn't want to lean out that motor!

E

09-17-2001, 08:08 PM	#1
STOCK LX Registered Member Join Date: Jan 2001 Location: San Jose Posts: 11	HELP! 50lb injector trouble. Help. I have 50lb injectors and a bullet 75mm MAF. I am getting a check engine light with a code 66 low MAF voltage. Is this because the 50lb's are so big that the voltage signal to the computer is below the low limit? Is there any way to correct this? Maybe with a different meter? The MAF has just been recalibrated, so that isn't it. Thanks.

09-17-2001, 09:12 PM	#2
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	Your injectors have nothing to do with it. A code 66 is caused by one of the following: Open MAF circuit Open VPWR circuit to MAF sensor Open PWR GND circuit to MAF sensor MAF circuit shorted to ground Faulty ECM or MAF sensor Air leak before or after MAF sensor MAF sensor disconnected Start checking! Take care ~Chris ------------------ Retired Moderator MustangNet My site: JimPorterRacing RACECAR spelled backwards is RACECAR HEY !!! Are you ASE Certified ??? If you are, ask me about iATN. The best tool you'll ever have, and it's free !!!

09-17-2001, 10:18 PM	#3
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	The real question is, why in the world are you running 50lb injectors that can support 1000hp on a 75mm MAF sensor?

09-17-2001, 11:06 PM	#4
STOCK LX Registered Member Join Date: Jan 2001 Location: San Jose Posts: 11	I have an ATI procharger, and I thought since it is a blow through it didn't need such a big meter. Also, the car runs fine with the stock MAF, and injectors, no light at all. So I don't think it is in the wiring.

09-18-2001, 06:00 PM	#5
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	Just as an FYI the ProM 75mm Bullit has had calibration problems with the 24lb injectors, this could be what you are experiancing with the 50lbers. How many hp are you going to be pushing?

09-20-2001, 11:42 AM	#6
STOCK LX Registered Member Join Date: Jan 2001 Location: San Jose Posts: 11	I don't know how much power. I can't dyno it yet, because it won't take full throttle!! It is a 393 with 8.5 to 1 comp. So I am thinking 500+? Also I think I found the problem, the MAF is only putting out .1 to .2 volts at idle. So I think the meter is defective.

09-20-2001, 01:08 PM	#7
bada$$lx Guest Posts: n/a	You're WAY over injected. Eve with the procharger, on a stock engine, 36#ers would've been more than enough. Not that that's the problem, just an observation. ------------------ '90 LX 5.0;12K original miles (no sh*&);3.55 gears; March pulleys;Edelbrock Performer Heads;BBK 1 5/8" equal length shorties;MSD 6AL ignition w/ blaster 2 coil;FMS E303 cam;Pro-M 75mm MAF;BBK 70mm TB; Eibach drag-launch spring kit;Southside welded subs;9" K&N cone filter charger;Hurst shifter;Cervini's 3" turbo hood;A/C delete; gutted cats;2 chamber Flomasters;Corbeau racing seats;FMS 30# injectors;JMS chip; Holley 190lb fp;TFS track heat Intake (12.299 @ 113 - 1.78 60')

09-20-2001, 01:14 PM	#8
302 LX Eric or '331 LX Eric' Join Date: Jan 1999 Location: Columbus, Ohio Posts: 2,142	Did you get the blow-thru type meter from Pro-M? The blow-thru type has a rim on each end of the meter to help keep the air tubes from blowing off in boost situations. Also, a properly built 393 with any decent amount of intercooled boost should produce some serious HP. Like in the area of around 650 HP! Keep us posted on your ride - sounds like one mean "STOCK LX." I'm curious about the details of your combo - would you mind providing some details? Also, IMHO, your injector size is just fine. A 393 stroker with a big huffer and high flowing heads, et al calls for some serious fuel demands. Take care, E ------------------ 1991 5.0 LX Coupe - 38,000 miles 13.17 @ 106.14 mph w/ 2.138 60' [This message has been edited by 302 LX Eric (edited 09-20-2001).]

09-20-2001, 07:33 PM	#10
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	Under injected? Not unless he's making over 900hp, and that would take some SERIOUS boost.

09-21-2001, 08:02 AM	#11
302 LX Eric or '331 LX Eric' Join Date: Jan 1999 Location: Columbus, Ohio Posts: 2,142	FYI (and FWIW), LaRocca's runs 50# injectors on several of their ProCharged 302/306s. I spoke to Jimmmy LaRocca a couple times regarding injector size about 9 months ago for my coupe. I too was skeptical of the large injector size, but Jimmy insisted on no less than 42's for my combo - and actually encouraged me to go with 50's. His expertise on ProCharged Mustangs is very extensive. I am no fuel system guru, just lending my observations. And, again, a properly built 393 w/ adequate cfm from a blower will make some serious HP. I sure wouldn't want to lean out that motor! E