Speed Density EFI Tuning
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Speed Density EFI Tuning
I have an '86 f150 5.0 with the Speed Density type efi and i know it's hit or mis as far as increasing air flow in and out of the engine. in some cases, the computer will lean out the air fuel mixture, and in others it works just fine. i'm planning on putting new gt40 heads on and high performance exhaust and cold air, and i was wandering if you could tune the computer for the new air flow? anyone who knows anything about it would be great help
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Joined: Jul 2008
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From: Long Beach Calimexifornia
I have an '86 f150 5.0 with the Speed Density type efi and i know it's hit or mis as far as increasing air flow in and out of the engine. in some cases, the computer will lean out the air fuel mixture, and in others it works just fine. i'm planning on putting new gt40 heads on and high performance exhaust and cold air, and i was wandering if you could tune the computer for the new air flow? anyone who knows anything about it would be great help
I've heard talk of replacing the stock Fuel pressure regulator w/ a adjustable & increasing PSI, but it's just talk. Don't know anybody that's done it. I wouldn't.
I could be wrong, but don't know OBD1 ECU's to be tuneable. However it's very easy to bump your base timing. 14BTDC as opposed to stock (10BTDC) is a respectable little kick in the ***.
See link.
This link also cover's ignition system upgrade, which I highly recommend: http://fullsizebronco.com/forum/show...ht=timing+bump
I drive an 87' 302 by the way.
Last edited by ymeski56; Jan 5, 2012 at 07:09 PM.
Senior Member
Joined: Jul 2008
Posts: 58,557
Likes: 1,165
From: Long Beach Calimexifornia
The problem is, because MAP does not measure actual air flow, the ECU does not know to compensate for extra flow. So it's not that the ECU is leaning it out, it just doesn't know to enrich it!
I've heard talk of replacing the stock Fuel pressure regulator w/ a adjustable & increasing PSI, but it's just talk. Don't know anybody that's done it. I wouldn't.
I could be wrong, but don't know OBD1 ECU's to be tuneable. However it's very easy to bump your base timing. 14BTDC as opposed to stock (10BTDC) is a respectable little kick in the ***.
See link.
This link also cover's ignition system upgrade, which I highly recommend: http://fullsizebronco.com/forum/show...ht=timing+bump
I drive an 87' 302 by the way.
I've heard talk of replacing the stock Fuel pressure regulator w/ a adjustable & increasing PSI, but it's just talk. Don't know anybody that's done it. I wouldn't.
I could be wrong, but don't know OBD1 ECU's to be tuneable. However it's very easy to bump your base timing. 14BTDC as opposed to stock (10BTDC) is a respectable little kick in the ***.
See link.
This link also cover's ignition system upgrade, which I highly recommend: http://fullsizebronco.com/forum/show...ht=timing+bump
I drive an 87' 302 by the way.