multiple codes - cannot figure it out....

[stangman16]

'66 Mustang with an '93 A9L GUFB style EFI setup. I have the quarterhorse by moates and binary editor from Clint. My problem is with the O2s, binary editor reports a steady voltage of .00125 from both O2s. I checked pin 29 and 43 at the back of the computer and both read ~.50 and fluctuating as they should. I have the non-HO firing order so I needed the quarterhorse to tune it with.

My KOEO: 15, 95 and then a 10 (Ford OBDI code reader from autozone)
My KOER: 41, 91
Engine passes multiple Cyl. balance tests

Either my computer (practically new) is toast or the software is not functioning correctly, because I'm getting the correct voltage readings for the EEC pins to the HEGOs and I've got 10.5+v to the HEGO heater wire in "RUN" position. I have double and tripple checked the HEGO wiring and can verify it is correct.

Any suggestions on what the next step would be?

 

[jrichker]

I see that you have an A9L computer. Did you do something with the tuner software to change the firing order? Using an A9L computer with a non HO firing order camshaft will result in the code 41/91 problems.

If you have not altered the firing order, the engine fuel injector harness needs to have come from a HO engine to get the fuel injector sequence correct.

If you have altered the firing order, your need a non HO engine fuel injector harness to get the correct fuel injector sequence.

Moving the pins around in the 10 pin connector does not fix the firing order problems caused by a computer and camshaft mismatch. You can do it if you don't wish to purchase the correct engine fuel injector harness and re-pin the one you have to match the existing firing order.

 

[stangman16]

yeah, its an A9L computer with non-HO firing order that I did change with the quarterhorse. I'm not sure how to identify which style injector harness I have - how can I verify this? And if its not the correct one, why would it not work if I re-pin the harness?

I really didn't want to buy a 5.0 camshaft (non-roller block) or 351w, but it's looking as if that would be the best option..?

 

[stangman16]

You can do it if you don't wish to purchase the correct engine fuel injector harness and re-pin the one you have to match the existing firing order.

Do you happen to have a diagram for the non-HO fuel injector harness? I'm surprised to see they are different, and I've not come across any diagrams in my searches for the non-HO injector harness. I'm real curious to know how they differ.

 

[jrichker]

See Ford Fuel Injection Injector Firing Order maybe there is some help there.

 

[stangman16]

See Ford Fuel Injection Injector Firing Order maybe there is some help there.

Yea, I've seen that page. I did step 2 - I reprogrammed the computer using my quarterhorse. So this should not be an issue causing the 41/91 then, correct?

Edit: If I go ahead and get this 351w hydraulic flat tappet cam with the HO firing order, new lifters and chain - will that solve the 41/91 issue I'm having? I still don't see why the tuner software is not displaying the voltages I'm reading from Pins 29/43 at the back of the computer. I am lead to believe the ECM is taking the same values as I'm reading with the volt-ohm-meter. But if the A9L, reprogrammed for the nonHO firing order, is not working & causing 41/91 - I would at this point just buy the HO style cam and get it over with. What do u suggest? I really don't understand why it would throw a 41/91 if the A9L is set to the same firing order as the nonHO cam I have in there - can you tell me more info on this?

here's the cam I"m looking at: Edelbrock 2182 - Edelbrock Performer-Plus Cam and Lifter Kits - Overview - SummitRacing.com

 

[jrichker]

Since my experience with moates and quaterhorse is very limited, I would recommend that you email or PM vristang. He is the resident tuner guy here and may be able to give you more help than I can. Send him the link to you post so that he can reply easily.

 

[stangman16]

PM sent, thankya!