1990 no start
Melting Slicks
Joined: Jan 2014
Posts: 2,183
Likes: 381
From: Lunenburg MA
Start with the basics. Does it have spark? Fuel pressure? Injectors pulsing? Not much else we can tell you without specifics on the alarm. You might want to invest in a factory service manual.
Thread Starter
Cruising
Joined: Jul 2019
Posts: 12
Likes: 0
Duh lol. Every thing turns on when I turn the key to the on position. But I get no crank and a brake indicator light comes on when I try to turn it over. I have fuel at the rail how do I check if the injectors are firing?
Team Owner
Joined: Jul 2004
Posts: 28,379
Likes: 3,261
From: Hartford WI
Hook up an idiot light to the exciter wire (not the positive cable) and try to crank. Is it getting 12V?
Safety Car
Joined: May 2001
Posts: 4,741
Likes: 1,639
From: Fairfax Virginia
Measure the Battery voltage and then measure it again at the fuse panel using the chassis for ground. They should be the same or close.
You might need a set of the Factory Service Manuals for your 1990. They are available for ~$85 in hard copy, RockAuto sells them much cheaper on a DVD. They have all the schematics and troubleshooting guides you could ever want in them and it is accurate to boot!
Your injectors all have 12 volts DC going to them when the Corvette is in the "Run" Position. The ECM will send a ground to make them inject the fuel. Be careful checking the wires around the injectors as their insulation might start coming off. I have seen several C4's with crumbling insulation on the injector wires that sit on top of the engine. You do not want to use any self powered testing device that might hurt the ECM.
Your Fuel system is in fact "priming" the engine to run but no cranking or starting?
You might need a set of the Factory Service Manuals for your 1990. They are available for ~$85 in hard copy, RockAuto sells them much cheaper on a DVD. They have all the schematics and troubleshooting guides you could ever want in them and it is accurate to boot!
Your injectors all have 12 volts DC going to them when the Corvette is in the "Run" Position. The ECM will send a ground to make them inject the fuel. Be careful checking the wires around the injectors as their insulation might start coming off. I have seen several C4's with crumbling insulation on the injector wires that sit on top of the engine. You do not want to use any self powered testing device that might hurt the ECM.
Your Fuel system is in fact "priming" the engine to run but no cranking or starting?
Last edited by ctmccloskey; Sep 5, 2021 at 11:36 AM.
Thread Starter
Cruising
Joined: Jul 2019
Posts: 12
Likes: 0
I'm pretty sure I have narrowed it down to the vats system. I bypassed the starter relay got it to crank but still no start. She has spark. Is there a way to bypass the fuel part of vats?
Last edited by Split29; Sep 8, 2021 at 05:31 PM.
