HELP ASAP LT1 swap starts wont stay running VATS? - Third Generation F-Body Message Boards

Tricked-Out-Toy · 11-13-2003, 02:48 PM

AIght heres what ive got, im doing a 97 LT1 swap into a 91 Z28, ive got a wiring harness simmilar to the painless one and ive taken the blue VATS wire and ran it to the VATS mudule located under the pass side dash, the car starts every time but stalls out after about 3-5 seconds, during these 3-5 seconds your can rev the hell outa the engine or just let it idle nothing changes, also the sup restraint light will flass and as soon as it goes out the car dies, PLEASE ANY HELP thanks guys- Tricked-Out-Toy

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Project: 85 2.8 bird · 11-13-2003, 03:03 PM

I'm not too keen on VATS, but maybe LS1.com might be able to give you some answers.
edit: THe LT1 wiring sticky up top may help also, if not looked at yet.

Tricked-Out-Toy · 11-13-2003, 03:16 PM

ya i checked most of the posts i searched but i cant find anything relavent!!!! its craxy teh car start and revs up no prolem for about 3 seconds then just dies but the security light goes out as soon as it starts????!!!!!!!!!????? HELPP!!

mat89RS · 11-13-2003, 04:21 PM

Are you using a Passkey (VATS) II ??? or the one that was already in your car ???

You could have a problem with the optispark.

TexasLT1 · 11-13-2003, 10:50 PM

yup sounds like VATS. although for mine it was only about 2 seconds that it would run

Trans Am#5 · 11-14-2003, 12:46 AM

I think we'll need a little more info here. Do you have a VATS bypass module for the LT1? If so, what kind....or did you have it programmed out of the PCM?

Tricked-Out-Toy · 11-14-2003, 07:38 AM

Aight now heres what i have it is the passky 2 style, its the one with the chip in the key, the harness was rewired for stand alone use but i do not have the vats module for the lt1 i have all the vats stuf from the TPI 91. I was under the impression with vats stuf i currently have i could tap into it for the LTI ??? thanks for the help guys.

edit. i didnt get the VATS programed out

Tricked-Out-Toy · 11-14-2003, 08:05 AM

also is there any way the problem could be in the SIR system?? because the security light goes out as soon as it starts- thanks for all the help

Trans Am#5 · 11-14-2003, 08:12 AM

I don't think you can just tap into the VATS system from the 91 setup. You will still need to bypass the VATS in the PCM. Either by module or programming out. The security light is for the original 91 VATS system. Someone correct me if I'm wrong.

Tricked-Out-Toy · 11-14-2003, 08:16 AM

is this "bypass mudule" a standard issue part? where do i get it? can i get one out of a 96-97 camaro? is there anyway to "trick" the PCM into thinking its there with out the bypass module? thanks alot

edit: im using the vats module from the 91 for the signal (blue wire)

Tricked-Out-Toy · 11-15-2003, 05:19 AM

Still looking for some input, ANYONE??? im dying to drive this thing!! thanks

Trickster · 11-15-2003, 09:10 AM

when you say you took the blue wire and ran it to the VATS control module, are you referring to the blue wire that runs from pin "B6" of the ECM to Pin "A2" of the VATS control module.

The Trickster!!!!!!!!!!

Tricked-Out-Toy · 11-15-2003, 12:23 PM

Do you mean the "B6" from the '97 PCM? B/C the '97 harness was rewired for stand alone use and had a blue wire labled VATS output. I took that wire and ran it to the blue wire located on the VATS control module of the '91 V28. (under passanger dash)

cd90rs · 11-15-2003, 12:37 PM

The guy that did my harness said you could tap into the VATS output signal that was existing in my car. The signal is the same. I believe its a 50hz sqare wave. Anyway, you should get your PCM programmed for your setup and when you have this done just get the VATS deleted. I had Madwolf do my programming. I was very pleased with his service.

Trickster · 11-15-2003, 12:46 PM

Ok,

The 97 models used a different VATS than the 91 models. GM used the Passkey I system up until about 93 and then switched over to the Passkey II system. As I mentioned in my last post, there is a blue wire that runs from the VATS control module to the ECM (signal wire).

The Trickster!!!!!!!!!!

Tricked-Out-Toy · 11-15-2003, 05:30 PM

ok it seems to be a standard issue to just have them deleted now my next question is rather than mess with getting vats to work what do i need to do it my self, i was burning my own chips for the TPI (obd1) hoow much diff is it change OBD2, not to get off topic by any means if someone knows exactly what i need to do right now to get this thing goin id love to hear it.....

now im getting a few mixed signals, will the existing VATS module from the 91 work for the 97 if so how??? because ive tried.
also i dont know if this was a fluke but i did have it running for about 15 mins then shut it off, but it wouldnt start back up and stay running, it continued to only run for about 5 seconds , i thougth maybe something got crossed but i couldnt find it and she still sits!?
again thanks for all the input!

Trans Am#5 · 11-16-2003, 12:15 AM

It would be much quicker to have Ion(Madwolf) do it for you. But if you are still interested... http://www.carputing.com/
This link has a lot of information you'll need.
For Ion's home page...check the link in my sig....he's on the contacts page.
The wire labeled VATS on the harness would have to be connected to a module such as one from Painless if you wanted to delete it without getting the PCM reprogrammed. I'd go the reprogramming route since you'll eventually want to get it done anyway and you wont be wasting money on the module. Only odd thing is that it ran for 15 minutes.

Tricked-Out-Toy · 11-16-2003, 06:17 AM

YA i think im going to get it programed out but i wanted to make sure everything else was good before throwing money into something that wasnt the problem but thanks for the help, ill let everyone know how it turns out!