VetNutJim

I've about decided to order up a Painless Wiring Harness but there's one big caveat.
The wiring harness requires their Memcal which has a pretty "extensive" price tag attached to it. Some dealers want North of $200 bones just for the MemCal.
The MemCal eliminates the VATS inputs/etc.
Anybody out there know a good alternative ??

I can program my own PROM but don't know what to do about the VATS or how to make the PROM ignore the VATS signals.

BTW, this TPI is going on my old '73 Chevy truck so I don't have any of the Vette stuff on it.

Help,help,help. ......

ZylaRace

What ECM are you using?
Early VATS can be bypassed w/ a simple in-wiring circuit. I'm fairly sure you can bypass it in the PROM as well.

When you say MemCal, you mean a special MemCal for the ECM to use their harness? (I have not looked at the Painless stuff for a while now.)

I used a Howell engine harness when I put a 165 in my 82 P-up. This was may years ago, shortly after the L98 hit the streets. Howell was very difficult to deal w/ back then. He must be retired by now. I think his stuff is still avail. See http://www.howell-efi.com/technical_...t/brochure.pdf


[Modified by ZylaRace, 9:34 AM 12/5/2002]

VetNutJim

Hi ZylaRace,

Thanks for the input.

I have both the 165 in case I want to use the MAF and the 730 for SD systems.

Form what I can tell, either ECM requires VATS to be removed from the PROM on the MemCal.
Painless sells the MemCal with the PROM but the price is totaly outrageous for it.
It's just against my "religion" to buy the wiring harness from them and then turn around and give them a fortune for a MemCal just so's I can use it!!!

Since I have no VATS system that must activate the starter solenoid circuit I'm wondering if this is just a flag in the PROM code that needs to just be set to OFF or FALSE.
I think Nathan Plemmons posted about this a few days ago.

My understanding is without the VATS defeat the ECM will not activate the Injectors during the start sequence. Is this true?

If the ECM just needs to see a specific value resistance during start to activate the Injectors, it seems that one "could" supply that resistance with a little hardwired resistor.
I've been told there are only about 16 different key pellet values so finding the one my particular ECM "likes" shouldn't be too much of a pain.

The truck is just my test mule to get the system running properly.
Ultimately the whole system will be transferred over to my '84 Vette.
Actually I have another whole system to install on it.

I've got a lot of info from dyi-fiy or is that diy-fyi???
ChevyThunder also has a LOT of information on TPI swaps.

How about it boys and girls? What do I need to do to get this to work?

-=Jeff=-

Using the 165 or thre 7730 all you need to do is deselect the VATS ont he ECM Switch section.. On the corvettes there is the CCM to control the dash which also controls VATS and will be something you will not need to worry about.

drive it

:iagree:

ZylaRace

I haven't turned off the VATs at the ECM before. Stands to reason it should just be a bit somewhere. If you wanna send me a PROM, I'm sure I can flip the bit for you.
To bypass it w/ hardware, the easiest way would be to tie a resistor across the VATs module. There is a simple oscillator circuit that can be wired in place of the VATs module, but I don't have those details available.


[Modified by ZylaRace, 9:10 AM 12/6/2002]

1960LS6

Did you get your TPI up and running???