305 TBI won't shoot gas on its own.

Thread Tools
 
Search this Thread
 
  #1  
Old 08-14-2007, 04:44 AM
titan's Avatar
Newbie
Thread Starter
Join Date: Aug 2007
Posts: 4
Default 305 TBI won't shoot gas on its own.

Hi everyone. It's my first post, and it's a question... Go newbs!!... Anyway, I've searched the forum and google, and I cannot find an answer, so now I'm asking. Here's the details.
1990 Camaro RS 305
TBI
700R automatic transmission

I have to pour gas in the carb to get it to start. Once it's started, I have to pump the gas, to keep it running. It does not shoot any fuel on it's own. But shoots plenty when I'm pumping the pedal. It dies as soon as I stop pumping. I have not had a way to check fuel pressure but I did pull the line loose and turn over the engine, and it pumped quite a bit, I'd say around 3 cups in about 2 seconds of turnover.

New parts I've put on it:
Fuel filter
Oil filter
Air filter
New oil
Plugs, gapped correctly
Plug wires
Distributor cap
Rotor button
All the fuses are good.

Used parts off my buddies firebird that we've tried swapping:
MAP sensor
ECU/ECM (which is the correct term please?)

Now the gory details:
Someone before I bought the car had swapped out the steering column and attempted the bypass the VATS system. I do not know what all they did, but I read on here that a jumper from the tan/white stripe in the console to the yellow ignition wire would bypass it. I did that and was able to crank the car from the inside. ( I had been jumping it from under the hood) If everything I've read is correct, the VATS kills the starter only. Is this correct, or could it be killing the injectors too? Remember I am able to crank it via ignition now, injectors are shooting when I press the pedal, and the starter is not disabled.

The car has not run since I bought it, and I did not hear it run before buying. I know I know... but it was only $600.00 and has all the AC components and little body damage.

The only code I get from the OBD is code 53, which is high voltage at battery. The computer is reading error codes, because we unplugged the MAP and coolant sensor and they registered error codes in the computer. I've been getting the codes by jumping pins 5 and 6 in the OBD plug.
The last things I can think to try is the O2 sensor.

I appreciate any suggestions anyone may have, and thank you for the time in reading this. I'm very good with electronics (MECP Certified) so I do have something to contribute back to the board.
 
  #2  
Old 08-14-2007, 11:38 AM
z28pete's Avatar
Tech Droid
Join Date: Aug 2005
Location: North East PA
Posts: 9,215
Default RE: 305 TBI won't shoot gas on its own.

The VATS kills the starter and injectors. You can cut the wires from the VATS to the ignition switch, and strap a resistor across the wires coming from the VATS, but the resistor has to match the one on the original key. If you don't know what the car had, there are 15 resistor values to choose from. The other option is to have the VATS deleted in the ECM software.
 
  #3  
Old 08-14-2007, 09:37 PM
titan's Avatar
Newbie
Thread Starter
Join Date: Aug 2007
Posts: 4
Default RE: 305 TBI won't shoot gas on its own.

So do these things sound symptomatic of VATS? Even though it shoots gas when I'm pumping the pedal? I take it the jumper from the tan/white in the console to the yellow ignition is not the only thing to bypassing the VATS? I've seen the resistor values on here, so if need be, I can just build combinations of each one, and try them one at a time. When you say having the ECM reprogrammed, would a performance chip do what I need? I was considering getting one anyway. I could also just put in a bypass module for the VATS, just as if I were adding a remote starter. I think this would be the way I would go, since I've done that quite a bit, though the resistors would certainly be cheaper. I just want to make sure this is the culprit before I persue this avenue of repair. So once again I ask, do these things sound symptomatic of VATS? Or could I go through all of this, just to find it's some $7.00 sensor...
 
  #4  
Old 08-15-2007, 07:50 PM
titan's Avatar
Newbie
Thread Starter
Join Date: Aug 2007
Posts: 4
Default RE: 305 TBI won't shoot gas on its own.

Problem solved. It WAS the VATS system. Even though I had bypassed the starter portion of it ( meaning I could get the starter to turn over) I still had to present the correct resistance to the ECM to get it to enable the injectors. I simply got all the different possible values from http://www.thirdgen.org/vats_passkey_system and began building the correct values going down the list. Under the steering column there will be a purple/white and white/black set of wires, joined by a plug. Unplug that and cut the plug off of the side farthest from the ignition. Strip your wires back about a quarter of an inch and begin twisting in your resistors, and trying to start the car. Keep in mind waiting 4 minutes between each try, due to the "lock out" feature of the VATS. The 3rd combination I tried worked, and the car fired up and idled wonderfully. After you have found your correct value, sauter in your resistor (don't get too much heat close to the ceramic part of the resistor). I also found a very nice tutorial on how to build a full bypass circuit very cheaply at this link: http://newrockies.ca/vatsbypass/ This was going to be my next step if the "one at a time" trick didn't do it. Thank you for replying z28pete.

Edit: Total cost of the fix, less than 10 cents if you buy the resistors individually, I had tons of them already, so the fix for me was free!
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Andross
70-81 General
15
08-26-2023 05:44 AM
irocktheIROC
70-81 General
4
04-03-2009 09:32 PM
Benny
Intake, Headers, and Exhaust
11
08-23-2008 02:07 PM
titan
Computer & Fuel Systems
1
08-21-2007 11:55 AM



Quick Reply: 305 TBI won't shoot gas on its own.



All times are GMT -5. The time now is 03:31 PM.