Help needed! C4 Pin30 66' EFI swap A9l..Details inside.

[mr_woodster]

Ok first off, thanks for atleast looking at this thread, double thanks if you can help me understand some of this wiring.

Currently i have a 66' mustang with a 89' harness and an A9L computer. The swap has been up and running for awhile but with some issues.

I'm trying to get a handle on understanding the Gear selector switch, Pin 30 and the IAB and how they relate to each other. I've looked over Ford fuel inejction.com along with a couple wiring diagrams (pin-outs).

My issues is this C4 and trying to wire in a working selector switch, so as to bump the idle when it goes into gear (load).

I've attached an image of what im talking about...the question marks are pretty obvious I guess.

From what i understand, Pin 30 (purple/yellow)is supposed to see crank power in order to drive the IAB open for a quick start (and cold warm up i)
would think).

The diagrams also say pin 30 is supposed to be Grounded ? I would imagine some sort of diode or relay i in order?

I'm trying to understand what signal the selector switch is sending to the ECM to drive up Idle speed for the gear engagment. Is it + or - or something else?

Is Pin 30 (p/y) live 12v when it cranks and then grounded when running (no meterable voltage?)


Thanks, hopefully someone can help clear this up. The more i look into keep the c4 the more i feel alone around here. Most people just use the t5 and im starting to see why!

 

[BK_CAULEY]

http://www.stangnet.com/mustang-forums/778036-what-do-about-91-harness-non-mustang-application.html

 

[Teddyzee]

It is my understanding that the clutch pedal position switch or nuetral safelty switch connects pin 46 and pin 30, allowing the engine to start. Other than in those conditions, they are not connected.

(I've swapped an EFI H.O 5.0 into my '97 Ranger, with a manual. The Ranger wiring relies only on a clutch pedal position switch, not the nuetral switch from the T-5)

I'm not aware of any other driveability side effects of these circuits.

 

[liljoe07]

Be warned that an Auto setup gets its ground for start voltage for the NSS through a body ground. The manual ECM(A9L) sources its ground from the SIGRTN(PIN 46) If you route start voltage using PIN 46 and 30 you will Fry the A9L ECM

 

[BK_CAULEY]

Be warned that an Auto setup gets its ground for start voltage for the NSS through a body ground. The manual ECM(A9L) sources its ground from the SIGRTN(PIN 46) If you route start voltage using PIN 46 and 30 you will Fry the A9L ECM

well you just threw a stick in my spokes. and what body ground is this? the where do i route it if i have a a9p?

 

[liljoe07]

Manual transmission setups source ground for the "in-neutral" signal from the SIGRTN ground circuit..... and automatic transmission setups source ground for the "in-neutral" signal from the starter solenoid-to-fenderwell ground.

 

[BK_CAULEY]

Manual transmission setups source ground for the "in-neutral" signal from the SIGRTN ground circuit..... and automatic transmission setups source ground for the "in-neutral" signal from the starter solenoid-to-fenderwell ground.

i dont recall any grounds from the starter solenoid? can you be a little more specific. im trying to get this mess straightened out here. so if i have an a9p where do i send the pin 30 wire to? i got that if i have an a9l i can just loop it to pin 46 and call it a day.

and does the connector #39 have to be hooked up in any kind of way? its just dangling there and im not sure of it.

 

[liljoe07]

You may need to take this to your thread.....LOL

 

[BK_CAULEY]

You may need to take this to your thread.....LOL

on the way.