C4VetteLS1

Im planning on getting ls1edit shortly (soon as paychecks permit) and the car is completely wired up still with the stock wiring harness which has a bunch of wires that dont go anywhere (stuff to eliminate and ill cut out later) Can i just hook up the computer and will the motor run fine with all the SES check engine lights and computer going crazy????

I just want to make sure the motor is running and ill eliminate all the stuff as i go. But right now lots of wires on the harness are unplugged for stuff im not going to use.

Speartech

iTrader: (14)

I don't know what your setup is, but you have to at least take care of VATS, or no starty <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

AndUAndI

If you want VATS to work, w/o elimination via LS1EDIT, you must do more than wiring. I don't know about other than 1998 model year, but I swapped wiring harnesses, steering column and the BCM (Body Control Module) from my 98 Formula wreck to a 94 Z28. Everything starts up just fine. Steering column takes the key with the resistor plug in it, the BCM reads the resistance and if OK, signals the PCM that it's ok to start and and keep the fuel running.

bgreen

Our Cobra ran fine w/o any editing (course we did some later). 2000 LS1 & 6 speed out of a Trans Am, stock harness, just modified a bit.

How does VATS not let the car start up ? I mean does it not prime fuel pump, no spark, no injector pulse.. ?

Curious as to why ours works and others haven't.

Speartech

iTrader: (14)

VATS shuts off injector pulses.

For yours to have "ran fine" means:

You moved enough of the donor cars electronics and accessories over to keep the VATS requirements satisfied;

OR

You added a 50 Hz oscillator on the VATS signal line to satify the requirement (Camaro and Firebird programs only!);

OR

The PCM was reprogrammed by someone, somewhere, turning off the VATS function.

bgreen

no, no, and *not that I know of*

Unless we did shut it off beforehand. I'll check with my buddy who did the LS1 Edit on it.

68LSS1

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> Our Cobra ran fine w/o any editing (course we did some later). 2000 LS1 & 6 speed out of a Trans Am, stock harness, just modified a bit.

How does VATS not let the car start up ? I mean does it not prime fuel pump, no spark, no injector pulse.. ?

Curious as to why ours works and others haven't. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'd like to know too. I believe the 2000 and later models are different than the '98 and '99's. On the '98's the 5vdc fuel enable signal to the PCM (injectors)is from the BCM. The ignition key has a "resistor pellet" that completes the circuit (also giving a certain resistance value) in order for the BCM to give the PCM the fuel enable signal. The engine will start, but if this signal is not received within 2-5 seconds, you lose the fuel enable signal (injectors).
I found a post on corvetteforum.net showing how to make a 5vdc/50 HZ signal generator to reproduce this signal (I don't thinks it's still there), but I thought it was from a LS1tech member. It was removable (a little plug in box) so even if the vehicle was hot wired, without the box, the car wouldn't get far!

John@PACE

Brian G - John @ Speartech is correct. I disabled VATS through LS1Edit otherwise the Cobra would only start and die. Sorry, I must of snuck that past you when we were playing with the wiring. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

John
www.PACEPerformance.com

<small>[ November 21, 2002, 11:14 AM: Message edited by: John@PACE ]</small>

Speartech

iTrader: (14)

Ahhhh.... Mr. Skiba at the root of the mystery! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

C4VetteLS1

anyone have some info on how disable vats with the resister? instructions?

70 LS1

iTrader: (1)

Here is the VATS box that 68LSS1 was talking about. It cost me about $15 in parts to make.

VATS

<img border="0" alt="[Corvette]" title="" src="graemlins/corvette.gif" />

<small>[ November 21, 2002, 02:48 PM: Message edited by: 70 LS1 ]</small>

bgreen

Damn you John!

You need to sneak more work past me when I start on the Jeep too <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

LS1swap

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by C4VetteLS1:
<strong>anyone have some info on how disable vats with the resister? instructions?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">what year PCM and did it come out of a Y-body or f-body. the f-body is easy. the only way you could do it with "just a resistor" is if you had the BCM

Scott(Billy Bob)

ok its been awhile since I had to do this back in my car installer days but Ill give it a try. Find the little whte wires incased in the orange coating(not yellow which will blow the airbag) and where they go into the computer. Take an Ohm meter to the key take was in the old car and measure it across the 2 little metal bands on it. Do this without holding your fingers on the terminals cuz this will show a bad reading. Take this Ohm rating and get you a resistor to match it or as close as possible ( its not exact science) and it will start. I think this will only work on the LT-1 cars .
Ls-1 cars : Viper makes a box to emulate the key being in the car. This forces you to have a spare made by the dealer and makes you have to leave it in a little black box in the car at all times( just break off the good end if you dont want a theif finding it and driving away). This comes with a little "lasso" that goes around the key cylinder usually for remote starting without the key actually in the ignition.
I hope im right and hope this helps people cuz I'll be needing it soon

Jay Johnson

iTrader: (16)

Gosh, that is the only trick?

I'm going to run a F-body engine harness(M6), freshly
burned in pcm with a known vin(M6), and bcm with a
known key resistance value.

I will be running an aftermarket fuel pump. So,
actually I don't need the bcm and resistor?
I'm hearing that the bcm/keyresistor keeps the fuel
pump running, is that correct?

Is that all it will take to make a stand alone harness run the motor?

Wow, there's shops out there that charge several
hundred dollars to convert a stock harness to a
standalone.

If that's it, I'll be dropping LS1's into EVERYTHING! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Jay Johnson

<small>[ November 27, 2002, 11:46 AM: Message edited by: Jay Johnson ]</small>

C4VetteLS1

ok so i make that little box and the motor will start and run fine just with some SES light problems?

sweeeeeeeeeeeeeeeeet

70 LS1

iTrader: (1)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by C4VetteLS1:
<strong>ok so i make that little box and the motor will start and run fine just with some SES light problems?

sweeeeeeeeeeeeeeeeet</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Just don't forget to supply fused power to all the pins on the computer that should have power and ground to all the pins that should have ground. I used the helms manual and found out what needed to be hot and what needed to be ignition hot.