LT1 EFI Question

[Eric Elliott]

Hello,
The VATS defeat problem can be cured by your local alarm system installer. A
resistor or a 555 timer chip are commonly used to defeat (make happy) VATS
systems.

Eric
-----Original Message-----
From: Jennifer and Brock Fraser <fraser at forbin.com>
To: diy_efi at esl.eng.ohio-state.edu <diy_efi at esl.eng.ohio-state.edu>
Date: Thursday, April 02, 1998 6:48 PM
Subject: Re: LT1 EFI Question


>>From: Ron Tyler <dcmckenna at worldnet.att.net>
>>Date: Wed, 01 Apr 1998 20:27:11 +0000
>>Subject: LT1 EFI Question
>>
>>Hello All,
>>
>>     I installed a '95 LT1 in my 240Z. I have removed EGR, air pump,
>>canister purge valve, shift indicator lamp, and MIL. Everything else is
>>intact. About 30 seconds after starting the car, the cooling fan
>>activates. Is this some sort of quasi limp-home mode due to the missing
>>components? The PCM *does* go into closed loop, so I am assuming that it
>>isnt a full blown "limp". Would I be correct?
>>
>>TIA
>>- --
>>Ron & Stephanie Tyler
>>'72 LT1/T56 240Z
>>http://www.whit.org/jcaudle/LT1-3.jpg
>
>
>Ron,
>
>I've got a twin-turbocharged LT1 in my Jaguar that runs on a '96 PCM.  I
>don't have any of the emissions-related equipment you mentioned on my car,
>and my fans don't turn on after startup. (The fans are PCM controlled, as
>in the factory f-body)  If '96 can deal with these losses (with OBD-II
>diags), then your '95 should.  Come to think of it, I've used my '95 PCM in
>the car with no fan errors as well...
>
>How did you defeat the VATS to be able to start the engine?  There are
>really only two possibilities...
>
>1.  modify the PCM data (re-program)
>2.  used the factory "body" wiring, including ign. key cylinder and factory
>key
>
>Assuming you didn't GUT OUT a F/B/Y car to get the body wiring, I guess
>somebody re-programmed your PCM.  I'd start there.  The first sign of a
>seriously un-happy PCM is a fan-on condition.
>
>There's one other thing puzzling me...  You say that the fans turn on after
>30 seconds.  This is very odd.  Usually the "I've lost my mind" PCM
>condition turns on the fans upon key-on, i.e- engine not necessarily
>running.  In fact, that's the DIY_EFI insti-check for a clean programming
>is "key-on, fans-no".
>
>The reason I mentioned the re-programming was that a programming error
>(incomplete file, incompatible T&E side, etc) can make the car run "OK" but
>have the fan-on condition.  A 96/97 PCM will set a code (don't recall the
>P-number) that indicates a calibration error...  I don't recall if this
>code is used in '95 or not.
>
>Does your scan tool indicate "FANS: YES" for the fan status?  Of course, I
>don't know what you are using for a scan tool.  Make sure that the PCM is
>really commanding the fans.  Are both fans on?
>
>Besides the fans, how does the car run?  Is the real-time data from your
>scan tool reasonable?
>
>Good luck,
>Brock
>