DIY_EFI Digest V4 #651

[Laura & Neil]

> Date: Fri, 19 Nov 1999 18:40:07 -0500
> From: Darren Floen <dfloen at tbaytel.net>
> Subject: Speed sensor
>
> Hi everyone.A while back i was asking questions about fuel injection for
> a 4.3,being swapped into a Toyota.Well,i have now found a newer engine
> to use.I picked up a 91 4.3 throttle body engine,from a Safari van.
>
> So now i need a wiring harness.I contacted Howell and Painless.Howell
> says a speed sensor is not required for the engine to run smoothly.Matt
> at Howell says that it will only affect the EGR,and not the IAC.
> Painless says that the engine will always be stalling on deceleration.
>
> My question is this.How will the IAC motor reset its position if it
> doesn't have a speed sensor input?It is my understanding that this
> happens when the vehicle reaches 30 MPH.
>
> There is no smog testing where i live.
>
> So,do i need a speed sensor or not?
>
> Anyone know of any good websites dealing with 4.3 swaps and such?
>
> Thanks,
>
> Darren Floen
> Thunderbay,Ontario
>

I assume this is going to be an engine and trans swap Darren
The stock trans for the late 4.3 G.M's is the TH700 or derivatives. This uses a PCM
controlled lock-up converter that is activated with the vehicle speed as one of the
inputs.
I'd say the speed sensor is very nessesary.

Neil