Engine 1992

stanley514

Founding Member
Dec 23, 2000
302
1
18
South Carolina
331cu A9P C&L meter green sample tube real Ford 42# Injectors. The car will start after plugs pulled and dried over night. It will not start but once. I'm having raw fuel blowing out the exhaust. 37psi fuel pressure. I've tried two A9Ps
Any ideas?
 
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Inj Flow Rate (@ 40 psid) Naturally Aspirated hp (@ 0.50) Forced-Induction hp (@ 0.65) 19 lb/hr258 hp @ 85% Duty Cycle199 hp @ 85% Duty Cycle24 lb/hr326 hp @ 85% Duty Cycle251 hp @ 85% Duty Cycle30 lb/hr408 hp @ 85% Duty Cycle314 hp @ 85% Duty Cycle32 lb/hr435 hp @ 85% Duty Cycle335 hp @ 85% Duty Cycle34 lb/hr462 hp @ 85% Duty Cycle356 hp @ 85% Duty Cycle36 lb/hr490 hp @ 85% Duty Cycle377 hp @ 85% Duty Cycle38 lb/hr516 hp @ 85% Duty Cycle398 hp @ 85% Duty Cycle39 lb/hr530 hp @ 85% Duty Cycle408 hp @ 85% Duty Cycle42 lb/hr571 hp @ 85% Duty Cycle439 hp @ 85% Duty Cycle44 lb/hr598 hp @ 85% Duty Cycle460 hp @ 85% Duty Cycle47 lb/hr639 hp @ 85% Duty Cycle492 hp @ 85% Duty Cycle60 lb/hr816 hp @ 85% Duty Cycle628 hp @ 85% Duty Cycle72 lb/hr979 hp @ 85% Duty Cycle753 hp @ 85% Duty Cycle80 lb/hr1088 hp @ 85% Duty Cycle837 hp @ 85% Duty Cycle98 lb/hr1333 hp @ 85% Duty Cycle1025 hp @ 85% Duty Cycle
It's possible your injectors are too big?
 
Dump codes sticky

Look at the top of the 5.0 Tech forum where the sticky threads are posted. One of them is how to dump the computer codes. Codes may be present even if the CEL (Check Engine Light) isn’t on. You don’t need a code reader or scanner – all you need is a paper clip, or if your lady friend has a hair pin, that will do the job.
I highly suggest that you read it and follow the instructions to dump the codes. http://www.stangnet.com/mustang-forums/threads/how-to-pull-codes-from-eec4.889006/
 
How do you know they weren’t stuck? I had a 2006 f150 that developed bad fuel injectors around 120k miles. The issue was that when you turned it off the bad injectors would leak gas into the cylinder. Startup would then be terrible and raw gas would come out the tail pipe. 2 bad injectors pretty killed an otherwise good motor as the gas washed down the oil and killed the cylinders.
 
I have a set of 24# and a Mark 8 meter. I have installed them hope to have it back together this week. I will report my findings.
MAF interchange for 93 and earlier Mustang.

Swapping the MAF sensors between different MAFs is a big no no. The MAF body and sensor are designed to match each other. Therefore you can't swap sensors between different part number MAF bodies and maintain proper calibration. The assembly is designed to match the computer’s internal program, and swapping a different MAF can upset the computer's calibration. In other words, your monster MAF probably won't match the calibration of your 5.0 Mustang computer.

The OEM Ford MAFs are not calibrated to injector size. The injector sizing is done in the computer’s internal programming. Aftermarket MAF’s “lie” to the computer in an attempt to fool the computer into changing the injector pulse on timing to match the increased airflow.

The exception to the above statements is if you have an aftermarket tuner system such as Moates Quarterhorse, Tweecer, or similar device. Then you can alter the computer's MAF transfer function table to match whatever MAF housing and sensor you have. The tuner device works in conjunction with a high quality Air/Fuel ratio meter so that you can tell what sort of air/fuel mixture you have a any given time.

The only other MAF that is a one for one swap for a 93 and earlier 5.0 Mustang is the 94-95 Mustang MAF.

94-95 Mustang GT MAF - $40-$100. It is 70 MM instead of the stock 55 MM on regular stangs built prior to 94. It uses a slip on duct on the side that goes to the throttle body and a 4 bolt flange on the other. You need a flange adapter to fit the stock slip on air ducting that goes to the air box. Wiring plugs right in with no changes. *1 *2

Once your replacement 70MM MAF is in place, disconnect the battery for about 10 minutes. When you reconnect the battery and start the engine, the computer will relearn the settings for the new MAF.

*1.) Metal flange adapter http://www.kustomz.com/components.html Buy the TR70 for $39.95. Or spend some time on eBay looking for one that may fit.

*2.) MAF & sensor interchange
The 94-95 Mustang 5.0 MAF & sensor is also found on:
1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.
 
How do you know they weren’t stuck? I had a 2006 f150 that developed bad fuel injectors around 120k miles. The issue was that when you turned it off the bad injectors would leak gas into the cylinder. Startup would then be terrible and raw gas would come out the tail pipe. 2 bad injectors pretty killed an otherwise good motor as the gas washed down the oil and killed the cylinders.
First they are new 2nd I put them under 65psi with carb cleaner in the line. I fired each one to verify all worked correctly. None of them leaked while under pressure. I used the same tool to clean other injectors and check for leaks.
 
MAF interchange for 93 and earlier Mustang.

Swapping the MAF sensors between different MAFs is a big no no. The MAF body and sensor are designed to match each other. Therefore you can't swap sensors between different part number MAF bodies and maintain proper calibration. The assembly is designed to match the computer’s internal program, and swapping a different MAF can upset the computer's calibration. In other words, your monster MAF probably won't match the calibration of your 5.0 Mustang computer.

The OEM Ford MAFs are not calibrated to injector size. The injector sizing is done in the computer’s internal programming. Aftermarket MAF’s “lie” to the computer in an attempt to fool the computer into changing the injector pulse on timing to match the increased airflow.

The exception to the above statements is if you have an aftermarket tuner system such as Moates Quarterhorse, Tweecer, or similar device. Then you can alter the computer's MAF transfer function table to match whatever MAF housing and sensor you have. The tuner device works in conjunction with a high quality Air/Fuel ratio meter so that you can tell what sort of air/fuel mixture you have a any given time.

The only other MAF that is a one for one swap for a 93 and earlier 5.0 Mustang is the 94-95 Mustang MAF.

94-95 Mustang GT MAF - $40-$100. It is 70 MM instead of the stock 55 MM on regular stangs built prior to 94. It uses a slip on duct on the side that goes to the throttle body and a 4 bolt flange on the other. You need a flange adapter to fit the stock slip on air ducting that goes to the air box. Wiring plugs right in with no changes. *1 *2

Once your replacement 70MM MAF is in place, disconnect the battery for about 10 minutes. When you reconnect the battery and start the engine, the computer will relearn the settings for the new MAF.

*1.) Metal flange adapter http://www.kustomz.com/components.html Buy the TR70 for $39.95. Or spend some time on eBay looking for one that may fit.

*2.) MAF & sensor interchange
The 94-95 Mustang 5.0 MAF & sensor is also found on:
1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.
I have a SCT chip and it's programmed for the 24s and mark 8 meter. The same chip was flashed for the lighting meter and 42#s. I haven't tried the 24s yet I hope to later this week.
 
First they are new 2nd I put them under 65psi with carb cleaner in the line. I fired each one to verify all worked correctly. None of them leaked while under pressure. I used the same tool to clean other injectors and check for leaks.

If they are new they are likely good. Agreed. The issue with mine is that they leaked when no power was going to them but still under pressure as the truck was just turned off. Instead of the pressure bleeding off back to the tank it just bled out into the cylinders of the bad injectors. When truck was started all that gas was just pushed straight through into the exhaust and out the tail pipes.