Difficulty tuning after mass air conversion
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
On that O2 wiring adapter, is the short pigtail connected to the pass side sensor and the longer one to the drivers side?
I suspect what they have done here is split the power and ground connections to feed both sensor.. which is fine, and only the left O2 signal wire itself is new. That should work fine as long as the sensors aren't switched left for right. Whatever one of those two connectors has the new (pin43) wire in it has to go to the drivers side.
I suspect what they have done here is split the power and ground connections to feed both sensor.. which is fine, and only the left O2 signal wire itself is new. That should work fine as long as the sensors aren't switched left for right. Whatever one of those two connectors has the new (pin43) wire in it has to go to the drivers side.
New User
Joined: Mar 2006
Posts: 9
Likes: 0
From: NorthEast Ohio
Our ECU's can run Speed Density or Mass Air. Out of thousands of customers essentially nobody uses Mass Air because speed density works so well. People who deal with this era of Fords have the "SD is bad" drilled into them but that statement isn't true once the stock ECU is out of the equation. SD is only bad when it's an ECU that you can't tune in which case mass air gives you more room for mods. That's no longer the case with an ECU you have full control over. Then mass air is just more cost and more complicated than it needs to be. Either way, our ECU's support it if you choose to go that way.
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Junior User
Joined: Jan 2019
Posts: 80
Likes: 1
On that O2 wiring adapter, is the short pigtail connected to the pass side sensor and the longer one to the drivers side?
I suspect what they have done here is split the power and ground connections to feed both sensor.. which is fine, and only the left O2 signal wire itself is new. That should work fine as long as the sensors aren't switched left for right. Whatever one of those two connectors has the new (pin43) wire in it has to go to the drivers side.
I suspect what they have done here is split the power and ground connections to feed both sensor.. which is fine, and only the left O2 signal wire itself is new. That should work fine as long as the sensors aren't switched left for right. Whatever one of those two connectors has the new (pin43) wire in it has to go to the drivers side.
Former Vendor
Joined: Apr 2019
Posts: 279
Likes: 3
From: Shawnee KS
Speed Density can be batch fired or sequentially fired, same for MAF. They are independent processes (MAF doesn't have to be sequential, it just was from the factory, and SD doesn't have to be batch fire, it just was from the factory). Our ECU uses all new components inside the ECU case so it is not constrained by anything Ford did originally. So we offer the PiMPx (batch fire, 4 at a time) or the PiMPxs (sequential injection, each fired independently). To fire sequentially you need to have the injector harness wired for sequential (8 injector wires to the ECU) rather than wired for batch firing (2 injector wires to the ECU). So factory batch fire applications use a PiMPx, or add the additional injector wires and can run the PiMPxs for sequential. Factory sequential applications would run the PiMPxs to retain sequential injection. PiMPxs and PiMPxshift (the one for E4OD and 4R70w/AODE trans) can do batch or sequential, it's just a software setting.
New User
Joined: Mar 2006
Posts: 9
Likes: 0
From: NorthEast Ohio
Speed Density can be batch fired or sequentially fired, same for MAF. They are independent processes (MAF doesn't have to be sequential, it just was from the factory, and SD doesn't have to be batch fire, it just was from the factory). Our ECU uses all new components inside the ECU case so it is not constrained by anything Ford did originally. So we offer the PiMPx (batch fire, 4 at a time) or the PiMPxs (sequential injection, each fired independently). To fire sequentially you need to have the injector harness wired for sequential (8 injector wires to the ECU) rather than wired for batch firing (2 injector wires to the ECU). So factory batch fire applications use a PiMPx, or add the additional injector wires and can run the PiMPxs for sequential. Factory sequential applications would run the PiMPxs to retain sequential injection. PiMPxs and PiMPxshift (the one for E4OD and 4R70w/AODE trans) can do batch or sequential, it's just a software setting.
Former Vendor
Joined: Apr 2019
Posts: 279
Likes: 3
From: Shawnee KS
Thanks for clearing that up. I want to change my '94 351 to sequential firing , but I thought a mass air conversion was necessary for that. I'll look closer at your PiMPxs material. I think I can handle the wiring modifications if I have an accurate pin out schematic.
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Junior User
Joined: Jan 2019
Posts: 80
Likes: 1
So I managed to get in contact with the IST tech again, He believes I have a fuel delivery issue. He instructed me to check fuel pressure at my fuel rails, said it should be 42psi with the vac line off.. also said I should get an adjustable fuel pressure regulator to upgrade from the old factory regulator. also said told him how I installed my 02 sensors and he said it was correct.
Former Vendor
Joined: Apr 2019
Posts: 279
Likes: 3
From: Shawnee KS
Didn't it previously run fine before you swapped on the MAF stuff? If so, while fuel pressure is always a good thing to check, it would be a rare coincidence that something in the fuel system failed at the same time as the MAF swap. It's an easy test so it's certainly worth doing, I just wouldn't throw money at the fuel system if the FP tests good and it ran fine before.
FYI, regarding your PM, I tried to reply but got this message:
cobolt911 has exceeded their stored private messages quota and cannot accept further messages until they clear some space.
FYI, regarding your PM, I tried to reply but got this message:
cobolt911 has exceeded their stored private messages quota and cannot accept further messages until they clear some space.
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Junior User
Joined: Jan 2019
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Didn't it previously run fine before you swapped on the MAF stuff? If so, while fuel pressure is always a good thing to check, it would be a rare coincidence that something in the fuel system failed at the same time as the MAF swap. It's an easy test so it's certainly worth doing, I just wouldn't throw money at the fuel system if the FP tests good and it ran fine before.
FYI, regarding your PM, I tried to reply but got this message:
cobolt911 has exceeded their stored private messages quota and cannot accept further messages until they clear some space.
FYI, regarding your PM, I tried to reply but got this message:
cobolt911 has exceeded their stored private messages quota and cannot accept further messages until they clear some space.
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Junior User
Joined: Jan 2019
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Ok so I checked the fuel pressure, 32PSI Engine off system primed. 30PSI engine running, and when the vac line is disconnected it increases by 10PSI to 40SPI. So all of that seems to be in spec of what it should be, a bit on the lower end of spec but still in spec. I also pulled some engine codes...
KOEO
31- EGR Valve position (EVP) out of range (Low)
67- Neutral drive switch open
84- EGR vaccum regulator circuit failure
29- No input from vehicle speed sensor
I tried all afternoon to get the KOER codes but it would not give me anything. I've followed steps online and steps in my hans manual, no response from the ECM. I also notice my check engine light wont come on at all, so I had to pull the codes I got with an anolog multi-meter. I even went to the extend to take the dash apart to change the check engine bulb and still no check engine light even though it should be on.
I also want to add that when I get a direct reading from the MAF (without dumb air adjuster) the truck will start and idle on it's own at 14.7:1 ratio. After maybe a couple seconds it then runs so lean (18+:1) that I can't even get a reading on the AFR gauge. When I switch back to how I set the truck with the air adjuster, no effect.. I try to enrichen it and still runs super lean. always 1 step forward 2 steps back with this.
SPE mailbox empty
KOEO
31- EGR Valve position (EVP) out of range (Low)
67- Neutral drive switch open
84- EGR vaccum regulator circuit failure
29- No input from vehicle speed sensor
I tried all afternoon to get the KOER codes but it would not give me anything. I've followed steps online and steps in my hans manual, no response from the ECM. I also notice my check engine light wont come on at all, so I had to pull the codes I got with an anolog multi-meter. I even went to the extend to take the dash apart to change the check engine bulb and still no check engine light even though it should be on.
I also want to add that when I get a direct reading from the MAF (without dumb air adjuster) the truck will start and idle on it's own at 14.7:1 ratio. After maybe a couple seconds it then runs so lean (18+:1) that I can't even get a reading on the AFR gauge. When I switch back to how I set the truck with the air adjuster, no effect.. I try to enrichen it and still runs super lean. always 1 step forward 2 steps back with this.
SPE mailbox empty
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
Based on your last post I'm gonna say you likely have wiring problems, and at least some(maybe all) of those may have been pre-existing so the problems are not necessarily at the PCM connector. VSS and EGR/EVR are all on the same PCM pins on both trucks and Mustangs so those things should just work.
I remember there being something different about the Neutral/drive switch between auto and manual vehicles that sets this code, so this one isn't unusual but I don't think it is significant either. The engine running tests available with the MAF mustang PCMs are more comprehensive than most of the trucks... it can do individual cylinder deactivation for example because of sequential injection, so the fact you can't get it to work says something... it could even mean that PCM has some internal problem.
I remember there being something different about the Neutral/drive switch between auto and manual vehicles that sets this code, so this one isn't unusual but I don't think it is significant either. The engine running tests available with the MAF mustang PCMs are more comprehensive than most of the trucks... it can do individual cylinder deactivation for example because of sequential injection, so the fact you can't get it to work says something... it could even mean that PCM has some internal problem.
Lead Driver
Joined: Jan 2019
Posts: 5,083
Likes: 868
From: N.W. Alabama
F350DET, has the IST installed, excerpt from his post #21,.... '1. The one thing missing from their instruction is, you must buy a 1989 Mustang EGR Valve Position Sensor and use it in place of the one on your truck. I had a trouble code re: that sensor (abbreviation for it is "EVP"), replaced it with another truck sensor, no change. Had to pay a local old Ford expert mechanic to diagnose it, and he advised the sensor output voltage ranges are different for truck vs 89 Mustang 302. He put the right sensor in, code went away.'
his thread...IST Products mass air kit - Ford Truck Enthusiasts Forums
his thread...IST Products mass air kit - Ford Truck Enthusiasts Forums
