91 won't start
Safety Car
Joined: Jan 2004
Posts: 3,556
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Thread Starter
6th Gear
Joined: May 2014
Posts: 6
Likes: 0
From: long island ny
thanks for any info
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Since it fires with an ether spray, you have spark.
Put a gauge on the Schraeder valve located on the passenger side of the fuel rail. Just unscrew the cap and attach the gauge.
Turn the key to On and FP should read around 45psi and hold.
If ok, next I would check injector firing; they are batch fire.
Here, pull the #1 injector connector and insert a test light or meter. Crank the engine to see if the ECM is firing them.
Put a gauge on the Schraeder valve located on the passenger side of the fuel rail. Just unscrew the cap and attach the gauge.
Turn the key to On and FP should read around 45psi and hold.
If ok, next I would check injector firing; they are batch fire.
Here, pull the #1 injector connector and insert a test light or meter. Crank the engine to see if the ECM is firing them.
Thread Starter
6th Gear
Joined: May 2014
Posts: 6
Likes: 0
From: long island ny
i found the valve and will check for fuel pressure. if fuel psi checks out will one injector cause the car not to start or you think its more than one.
the old owner said it was a 50.00 dollar part, i was thinking a relay something. is there any common part that goes bad that will cause this problem for 50.00 bucks ???
the old owner said it was a 50.00 dollar part, i was thinking a relay something. is there any common part that goes bad that will cause this problem for 50.00 bucks ???
Racer
Joined: Nov 2010
Posts: 413
Likes: 2
From: Carencro LA
i found the valve and will check for fuel pressure. if fuel psi checks out will one injector cause the car not to start or you think its more than one.
the old owner said it was a 50.00 dollar part, i was thinking a relay something. is there any common part that goes bad that will cause this problem for 50.00 bucks ???
the old owner said it was a 50.00 dollar part, i was thinking a relay something. is there any common part that goes bad that will cause this problem for 50.00 bucks ???
C4 fuel pumps can be bought for less than $50, and it's very easy to change
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
I don't think that one bad injector would cause a no start. Checking both #1 & #2 injctors would verify that the ECM is firing both banks.
There are a number of relays, including the FP relay, but most are more like $25 or so. If you get no fuel pressue you can force the FP to run by grounding ALDL pin G (lower left) or jumpering to pin A (upper right). The ALDL terminal is located under the hush panel to the right of the driver's knee.
Your ECM uses a Speed Density (SD) system instead of a MAF to measure air flow. Part of the SD system is the MAP sensor, which measures air pressure. I believe this sensor is locater near the rear of the RH plenum but a '90 or '91 Vette owner need verify.
BTW, if you can find a good copy of the '91 FSM by HELM it will be a most valuable too now and in the future.
There are a number of relays, including the FP relay, but most are more like $25 or so. If you get no fuel pressue you can force the FP to run by grounding ALDL pin G (lower left) or jumpering to pin A (upper right). The ALDL terminal is located under the hush panel to the right of the driver's knee.
Your ECM uses a Speed Density (SD) system instead of a MAF to measure air flow. Part of the SD system is the MAP sensor, which measures air pressure. I believe this sensor is locater near the rear of the RH plenum but a '90 or '91 Vette owner need verify.
BTW, if you can find a good copy of the '91 FSM by HELM it will be a most valuable too now and in the future.
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Joined: Apr 2002
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From: Anaheim CA
Your car will run just fine on 7 or even 6 cylinders, so it doesn't hurt to disconnect one injector for testing.