Help with Lt1 swap!!!!

[Guest dirtyt]

I just got done with my swap. and it fires up and runs for about 3 seconds then dies. i didnt delete vats but i ran a inline walbro 255 wired into my stock ignition. i deleted a few things from my harness but all checks out to be right i just dont know why it wont stay running any help would be great!

[wheelman]

You'll have to either program the VATS out or put a resistor in the correct circuit of the PCM to fool it into thinking the correct key is in the ignition.

I have no idea what the resistor value should be but if you search http://www.ls1tech.com you should be able to find it.

It's easier to program it out though. Check out TunerCat (http://www.tunercat.com) and LT1Edit (http://carputing.tripod.com/9495LT1Edit.htm) to program the PCM.

You need to get an ALDL cable, they're available from AKM Electronics (http://www.akmcables.com).

I use TunerCat and find it easy to use and sort of intuitive, although there are so many variables that can be modified it's a little overwhelming at first.

 

You should also do a search on this site, there are many threads with questions about the LT1 specifically which you will find useful.

 

One thing you might consider is rewiring your fuel pump to run off a relay thats controlled by an oil pressure switch. This will cut the pump off should the engine die due to a cut fuel line or a sudden loss in oil pressure.

If you have the JTR manual the wiring is described in there and your LT1 should have the correct pressure switch already.

 

Wheelman

[Guest dirtyt]

Thanks for your reply. I had some mis information about the vats and thought it would still run with out a bypass. but after long hours of testing i relized im dumb and its the vats.

 

Now my question is... they have those 25 dollar units on ebay. but i dont have anything from firewall back. all i got with my motor was the engine harness and the stuff that went thru the fire wall cut.

 

I assume i have to wire something in to the fuel enable wire on the pcm but i dont know if that ebay thing will. i sent them a email but i thought perhaps some one here has tried one and can tell me if there a pile or not.

 

Thanks

Bryan

[jbc3]

I don't know anything about the ebay product, but I frequently suggest calling Dana at LT1350.com for any LT1 wiring issues. He has a module.

 

Jody

[deja]

I don't know anything about the ebay product' date=' but I frequently suggest calling Dana at LT1350.com for any LT1 wiring issues. He has a module.

 

Jody[/quote']

I think one of the mudules sold on EBay is LT1.com.

http://cgi.ebay.com/ebaymotors/VATS-Bypass-Module-LT1-LS1-and-many-other-GM-vehicles_W0QQcmdZViewItemQQcategoryZ33598QQihZ018QQitemZ280013189753QQrdZ1QQsspagenameZWDVW

[HB280ZT]

I used PCM for less to reprogram my LT1 in my 96 Impala SS and they did a very good job.

 

http://www.pcmforless.com/

 

Not to mention they even came to one of our local dyno days to program peoples car, very nice! Got an extra 15 hp out of mine on the dyno, not bad.

 

HB280ZT

[240playtoy]

Here's the VATS bypass I used, a bit bigger. didn't see the other one from LT1350.com back then. Pretty sure it wires to a blue wire off the PCM, that and ground and power. I've got it hooked to a switch for a poor man's antitheft system.