OK, half Camaro.
Front sub frame from 1969 Z28 Camaro with discs.
Posi rear end from 70 Camaro
Motor 305 TPI from 1987 Camaro with 1991 Computer and wiring harness
Trans 700 R4 from 1990 Camaro
1957 Chevy truck with 1956 GMC front clip, 3" chopped roof and presently 1969 rear fenders (but those are going away before paint).
Oh the drive shaft is out of a 1991 Camaro as well.

I'm building this on a budget to be a daily driver that averages 20 something MPG and will scoot when I need her to. I remember averaging 25+ MPG back in the day in my 88 Iroc and my 1986 Trans am if I took it easy. So after re-gearing the rear I'm hoping that this approaches that. Anyway, first post story time..

I pulled the 1987 wiring harness off the motor and I'm in the middle of putting on the 91. While trying to figure out some stuff I find the VATS curse info. I have a black wire coming out of B6 on the ECM plug on the wiring harness, I don't know if this wiring harness was from the same car as the ECM and Memcal?? So I need to get everything hooked up to find out if I'm screwed?!? What an awesome way to trouble shoot too, if the ignition module is messed up or something I won't be able to troubleshoot anything until I know I have a memcal that is burnt or came out of a car without the VATS crap.

I found a guy on ebay that sells custom burned memcals for $59 that delete the VATS and also the EGR, AIR pump stuff, and the CCP as well since I'm not running any of that. Yes I have the right knock sensor and I'm putting a O2 sensor in my headers. The trans has the speedometer output and I'm running a mechanical speedo, I was told it will run fine without a VSS.

So to summarize: 1.should I just pay the $59 for the burned memcal?
I've seen the VSS inline conversion deals, but
2.does the compute need the VSS?

I have been scouring these boards for the last few weeks putting this all together and they have been great! I can't seem to find the answers to these questions, so thank you in advance. I uploaded pics to my profile, so you can see what's up. I have a sensor question that should be self evident by the 2nd pic?

 

IIRC by '90, all TPI had VATS

There are several options,
could discuss them with this member
https://www.thirdgen.org/forums/post...781-post4.html

or buy a aftermarket unit that only generates the fuel enable (VATS ) signal required by the ECM ( can be found elsewhere as low as $15 )
http://www.bakerelectronix.com/products_vats/

 

Depends on you definition of " fine " ?
Maybe your " advisor "needs to come here more often ?

https://www.thirdgen.org/forums/post...740-post4.html
https://www.thirdgen.org/forums/post...475-post6.html


This unit will generate the required signal
http://tpiparts.net/inc/sdetail/10956/7587

 

Ok well now I know to copy a post before I submit it as this site logs me out and loses responses randomly.
Yay

Anyway That VSS adapter deal will work and now I know it needs to go on the backburner for when I have the funds to run 100%. That will get done, but right now I just need this to run OK and I can fine tune stuff from there.

$20 will get me the VATS bypass, I had looked at those but it seemed like they still needed the under dash module? I'll look into it more, if it just plugs into some ECm wires that'll work. Assuming it will work and I'm all about saving a few bucks right now, this project is already over budget!

Since I'm not running any emissions stuff (I've already removed the air pump/etc. and got the right belt to delete it) will I have any drive-ability issues if I don't get the memcal made to delete them? I won't have a check engine light hooked up; not anytime soon anyway, it's a down the road goal.

Thanks,

 

What exactly are you buying ?

A VATS " bypass " is not what you want.
It only " fools" the VATS module ( which you don't have ) into thinking the correct key is being used so it supplies the fuel enable signal to the ECM

A "fuel enable " signal generator connects directly to the ECM terminal you mentioned , and replaces the signal expected from the missing VATS module
Check out item # 281179660936 on that popular auction site

Only the EGR delete will generate a code and turn on the SES light

 

That's the $20 (with shipping) unit I'm referring to, they call it a VATS bypass. I can use that to solve the VATS problem which is great news as it's uber affordable. However eventually I'd like to have a check engine light so I know if there are issues right away. Item # 190811631147 on that same site seems to do it all..
Leaning towards the custom memcal. Now figuring out what all these unused connectors are for (needed or not) and getting the vacuum stuff right.

 

Only vac you need is the fuel reg vac hose to a intake port at rear and the vac connection to the MAP sensor.
Your '87 plenum doesn't have provision for the ' 91 MAP sensor ( as shown on left )
so you will have to remote mount it like done on the TBI's and run a line ( as short as possible ) to the other vac port
There is a redundant small vac port under the TB and a large vac port on the pass side that needs sealing.


l]

................................................................................
On the CCV system, a supply hose goes from the top port on the TB to the pass side cover , the PCV valve is located in the drv side.
For your app disregard the purge plumbing shown

 

I'm having the custom memcal burned that deletes EGR, HVAC, Air pump stuff in addition to the VATS! $59 shipped for that and I'll get nearly half of that back for my factory chip (a core credit if you will). $20 to just bypass the VATS or $30 to fix everything so it won't be throwing codes for the emissions junk that I don't need! Hopefully I can sell this emissions crap for $30 and it's essentially free.

I have the rear vacuum line for the Fuel pressure regulator on that, the one next to it goes directly into the MAP, and the one up front behind the throttle body is going to be plugged as I'm deleting the HHC.

I had a driveline from my 69 Nova sitting in the backyard that slipped right into this, SCORE! Beats lengthening the other one, wallet took a sigh or relief.

 

just a FYI If your going with a v6 modified memcal for speed density you will not have any knock retard control. unless you wire in the esc for a tpi maf and solder on a 3.9k resister on the memcal.

 

So long as I don't get any watered down gas I don't think it will be an issue, but thanks for the heads up. I will not be soldering anything on the memcal, I know to ground myself and not be charged with static electricity before I handle them and not touch the connectors. If it wasn't for the VATS engine blocking me I would have made do with the stock chip for awhile.

 

You can bypass the vats with a modulated 30hz @ 50-60% . if you do have a stock memcal and decide you would like it reprogramed I offer that service as a vendor here .
http://www.ebay.com/itm/GM-VATS-or-PASSkey-II-Bypass-Module-For-LS1-and-LT1-/281179660936?pt=Motors_Car_Truck_Parts_Accessories&hash=item41779d2288