Cold start injector
Thread Starter
Intermediate
Joined: Jan 2024
Posts: 26
Likes: 0
Cold start injector
Hello, I’m having an issue with a no start, I’ve check sparked and fuel pressure, and used a noid light on the injectors and even the cold start Injector and they all flash. However I still wonder if it’s not working. Does anyone have any recommendations on how to test the cold start injector further than just the connector to a noid light? Thank you
Thread Starter
Intermediate
Joined: Jan 2024
Posts: 26
Likes: 0
- Connect your fuel gauge to the rail.
- Run the fuel pump to pump-up the pressure. Let it stop.
- Note the static fuel pressure.
- Apply battery voltage to the two pins in the cold start injector. Fuel pressure should drop, and you usually can hear the "spray" in the manifold. If there is no pressure drop, the injector doesn't flow/'work'.
I also know there is a way to bypass it. Do you know how to do that, and if it’s easy or even worth doing that?
Heel & Toe
Joined: Sep 2024
Posts: 18
Likes: 0
From: Winnipg, Manitoba, Canada
1984 cold start injector
If you confirm that you have a stuck or non-op cold start injector and can't find another one, there are work-arounds.
If you have an automatic, it is reported that the 1989 calibration can be used in the 87. (89 does not have a CSI, the 89 program has changes to the cranking fueling. 89 was a 6-speed transmission, so the 89 calibration will not support the 86-88 4+3 Overdrive.)
In the "Solar 88" thread, just yesterday, tequillaboy and I discussed CSI and fueling. So look near the end of the thread. We discussed while cranking, applying as much throttle as possible without entering clear-flood as 75% throttle almost doubles the Injector Pulse Width. Tequilaboy brought up that this also opens the throttle which will lean the mixture. So this may or may not work.
Earlier in the 88 thread, I mentioned rigging a temporary wire from the ground side of either bank of injectors and while cranking, use the wire to ground max-open one side to introduce more fuel. << I've never tried this, but it should do about what the CSI does. Other than first start of the day, this shouldn't be necessary. If it works, and you want a more permanent installation the necessary wires are at the ECM on the passenger side of the car. Should be an easy 2-ish hour project to implement. If you prove that it works for you.
If you have an automatic, it is reported that the 1989 calibration can be used in the 87. (89 does not have a CSI, the 89 program has changes to the cranking fueling. 89 was a 6-speed transmission, so the 89 calibration will not support the 86-88 4+3 Overdrive.)
In the "Solar 88" thread, just yesterday, tequillaboy and I discussed CSI and fueling. So look near the end of the thread. We discussed while cranking, applying as much throttle as possible without entering clear-flood as 75% throttle almost doubles the Injector Pulse Width. Tequilaboy brought up that this also opens the throttle which will lean the mixture. So this may or may not work.
Earlier in the 88 thread, I mentioned rigging a temporary wire from the ground side of either bank of injectors and while cranking, use the wire to ground max-open one side to introduce more fuel. << I've never tried this, but it should do about what the CSI does. Other than first start of the day, this shouldn't be necessary. If it works, and you want a more permanent installation the necessary wires are at the ECM on the passenger side of the car. Should be an easy 2-ish hour project to implement. If you prove that it works for you.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski