LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

93 T/A, bypassed VATS, still need help

Thread Tools
 
Search this Thread
 
Old Feb 18, 2014 | 11:46 AM
  #1  
blackhawk400's Avatar
Thread Starter
Registered User
 
Joined: Feb 2014
Posts: 1
93 T/A, bypassed VATS, still need help

hey all,

background story is that i've had this 93 T/A a long while and keep letting it set up since it's just a project. usually have to jump it off to get it started but she runs great. also, i think the alternator might be dying too. so a few weeks ago i jumped it off, drove it to my new house an hour away, stopped for gas a block from the house and it never started back up.

no click or anything. not the starter. not the battery. definitely VATS. so i bought a resistor from radio shack and wired it in. fires right up, drive it home and park it. couple days later i go to start it up and nothing. no click or anything again. so i replace the resistor with a new one, solder it in and still nothing.

since then i've bypassed the crank enable relay (green and yellow under the passenger side dash, to the right of the glove box) and i've bought the VATS bypass module off ebay (to get the computer to send fuel far as i know)and i'm seeing it's LED flashing for me. i've got power to the pink wires on the injectors, i've got power to the crank wires i jumped, and i'm getting power to the coil. it turns over and starts to fire up but dies. it did start once and i pulled it in the garage and changed the oil. but now i can't get it started to get it back out to the driveway.

at a loss now. can't find any further info, just a bunch of threads on buying a resistor. looked through my haynes and the only service manual i have is for a 1998. no luck.

i think next steps would be spark plug tester/ noid light/ try the 50hz option on the module?

wrote some more notes before falling asleep...

Resistor Pellet bypasses the key chip so decoder gives 1. ok signal for injectors to fire and 2. ground for starter enable relay.

Unplug resistor and try since i've installed bypass module? same results?

Bypass module skips the decoder and gives ok signal for injectors to fire but requires jumper wire for starter enable relay.

Try 50hz signal from bypass module?
Check decoder for power/ground?
Unplug decoder and try again / mixed signals?
Retest ohms on key chip and add extra resistors to bypass, test with bypass module unplugged and functioning decoder?
Check plugs for spark with inline tester?
Check injectors for PWM pulse with noid light?
Check coil for strength?

maybe i'm heading in the right direction?
Old Feb 18, 2014 | 02:40 PM
  #2  
Injuneer's Avatar
Administrator
 
Joined: Nov 1998
Posts: 71,110
From: Hell was full so they sent me to NJ
Re: 93 T/A, bypassed VATS, still need help

Originally Posted by blackhawk400
hey all,
........ definitely VATS. ........
And you determined this based on the "SECURITY" light?
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
68camaroboltz
Fuel and Ignition
2
Oct 5, 2015 01:46 PM
colts0455
LT1 Based Engine Tech
39
Oct 4, 2015 09:47 PM
Bxlt1
Drivetrain
2
Sep 29, 2015 03:18 PM
colts0455
LT1 Based Engine Tech
5
Sep 27, 2015 01:07 PM




All times are GMT -5. The time now is 11:20 AM.