90 Vette won't start
Thread Starter
Racer
Joined: Mar 1999
Posts: 258
Likes: 13
From: New Mexico
90 Vette won't start
I ran my 1990 C4 L-98 Vette out of gas, after refilling the car it won’t start.
I changed the fuel filter, and switched too a different set of fuel injectors. Still no start. I measured the TPS voltage and had .85 volts closed throttle. We sprayed gas in the intake and still the motor did not start. I measured the fuel pressure; with the key on, it is 8 to 10 PSI. Cranking the motor the fuel pressure is 40 PSI. Additionally I changed the ECU, and the MAP sensor, and still no start. Any ideas on what is wrong?
I changed the fuel filter, and switched too a different set of fuel injectors. Still no start. I measured the TPS voltage and had .85 volts closed throttle. We sprayed gas in the intake and still the motor did not start. I measured the fuel pressure; with the key on, it is 8 to 10 PSI. Cranking the motor the fuel pressure is 40 PSI. Additionally I changed the ECU, and the MAP sensor, and still no start. Any ideas on what is wrong?
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 41
From: Baltimore, MD USA
If the only problem was you ran out of gas, you could have damaged the fuel pump.
Fuel pressure should be around 35-40 psi after you stop cranking the engine. The pressure should hold and slowly bleed off.
The in the tank fuel pump sock/filter could also be clogged with rust. Only way of telling is to pull the fuel pump.
Pull the vacuum hose off of the fuel pressure regulator and verify there is no gas in the vacuum line. If there is, that would indicate the fuel pressure regulator is bad.
As for spraying gas in the intake, did you manually open the throttle body and spray the gas into the intake?
You didn't mention you checked for spark.
The TPS .8 volts is close enough for the ECM.
When you replaced the ECM did you use your original MemCal/Eprom?
Have you checked for trouble codes by shorting pin A to G ?
Codes will be displayed on the speedometer LCD.
Fuel pressure should be around 35-40 psi after you stop cranking the engine. The pressure should hold and slowly bleed off.
The in the tank fuel pump sock/filter could also be clogged with rust. Only way of telling is to pull the fuel pump.
Pull the vacuum hose off of the fuel pressure regulator and verify there is no gas in the vacuum line. If there is, that would indicate the fuel pressure regulator is bad.
As for spraying gas in the intake, did you manually open the throttle body and spray the gas into the intake?
You didn't mention you checked for spark.
The TPS .8 volts is close enough for the ECM.
When you replaced the ECM did you use your original MemCal/Eprom?
Have you checked for trouble codes by shorting pin A to G ?
Codes will be displayed on the speedometer LCD.
Last edited by Hooked on Vettes; Jun 7, 2014 at 05:37 PM.
