what does vats disable, and where can i get a 1990 corvette vacuum hose diagram?
08-30-2009, 04:39 PM
#2
Team Owner
Member Since: Mar 2001
Location: Cincinnati, Oh USA
Posts: 53,932
Likes: 0
Received 26 Likes
on
23 Posts
VATS will not allow the start enable relay to close so the starter motor will not crank the engine. VATS also will not allow injector pulses, so the engine will not get fuel and run. I don't know where you can get a vacuum hose diagram, but I am sure someone will supply that info shortly.
08-30-2009, 11:33 PM
#3
Advanced
Thread Starter
Member Since: Aug 2009
Posts: 51
Likes: 0
Received 0 Likes
on
0 Posts
VATS will not allow the start enable relay to close so the starter motor will not crank the engine. VATS also will not allow injector pulses, so the engine will not get fuel and run. I don't know where you can get a vacuum hose diagram, but I am sure someone will supply that info shortly.
08-31-2009, 12:07 AM
#4
Team Owner
Member Since: Mar 2001
Location: Cincinnati, Oh USA
Posts: 53,932
Likes: 0
Received 26 Likes
on
23 Posts
"Turning over", is a term used to describe the starter motor cranking the engine. If you can unplug the wire from the ign lock that has a 2 pin plug on it and the starter motor will still crank the engine, then someone has installed some kind of defeat for VATS. Also, spark plugs shouldn't be wet from a fuel injected engine. You need a noid light (parts store) or make one with an LED (light emitting diode) in series with a 680 ohm resistor (both available from Radio Shack) and connect it to an unplugged injector and see if it pulses during cranking. This tells you that the injectors are being pulsed by the ECM and VATS is bypassed or at least working properly. If you make a noid light, it must be connected with the correct polarity across the injector socket, try it both ways.
Check for spark with a timing light during cranking and check for correct spark timing. Check for injectors receiving pulses during cranking. Check for fuel pressure and that it holds up for a long time after the ign is off. If you have all of this, then measure compression. Engines require spark and spark at the right time, fuel and air and in the correct ratio and compression in order to start and run.
Check for spark with a timing light during cranking and check for correct spark timing. Check for injectors receiving pulses during cranking. Check for fuel pressure and that it holds up for a long time after the ign is off. If you have all of this, then measure compression. Engines require spark and spark at the right time, fuel and air and in the correct ratio and compression in order to start and run.
