1989 Vette ECM
Instructor
Joined: Nov 2003
Posts: 102
Likes: 0
From: Fountain Valley CA
Same here on my 89: hard start when cold, but fires right up when warm/hot.
I've resigned myself to the fact that it's "normal" for an 89. I've experimented with spraying starter fluid into the intake plenum on a cold start, and it fires right up everytime.
BTW, I replaced my stock Multec injectors about 6 months ago after 120K; 3 of them read between 8-10 ohms, and the cold-start problem was present then.
Went with Multec's after the pink ones from 5-0 Motorsports didn't work out. It was an exchange plus about $150 for the swap.
I've resigned myself to the fact that it's "normal" for an 89. I've experimented with spraying starter fluid into the intake plenum on a cold start, and it fires right up everytime.
BTW, I replaced my stock Multec injectors about 6 months ago after 120K; 3 of them read between 8-10 ohms, and the cold-start problem was present then.
Went with Multec's after the pink ones from 5-0 Motorsports didn't work out. It was an exchange plus about $150 for the swap.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
How frustrating! Spraying starter fluid into the plenum and having it fire right up means there's not enough fuel. Can you get it to start by turning the key on and off a couple times making sure there's plenty of fuel at the rail? Pressure ok?
Instructor
Joined: Nov 2003
Posts: 102
Likes: 0
From: Fountain Valley CA
It'll start without the starting fluid. My sequence to do a cold start is to turn ign. on and let the fuel pump pressurize the fuel rail, then I crank the starter till I hear it cough (about 3-5 secs.), turn key off, wait a few secs., then try to start. It usually starts on the second short burst of the starter.
The only time I use starting fluid is when I'm experimenting with another cold-start procedure and need to compare results.
I know I'm not getting enough fuel for the cold-start. What I'm not sure about is if there is a circuit or system on the 89's that is supposed to "richen"the fuel mix for a cold-start?
The only time I use starting fluid is when I'm experimenting with another cold-start procedure and need to compare results.
I know I'm not getting enough fuel for the cold-start. What I'm not sure about is if there is a circuit or system on the 89's that is supposed to "richen"the fuel mix for a cold-start?
Heel & Toe
Joined: Aug 2004
Posts: 15
Likes: 0
yeah!
Originally Posted by evitagenone
Will an ECM from any other year and or model work in an 89? I am having injector/ECM problems too on a brand new L98 383. What is up with 89s and injector problems!!!! 
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
'89 cold start is controlled by the ECM which adds more fuel or pulse width to the injectors. Signal is from the Engine Coolant and Engine Air Temp Sensors so either might be part of it. Both should read or be close to ambient air temp on a cold engine. I'd check the key on fuel pressure too with the engine cold. Should be 42psi and steady.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by SunCr
I'd check the key on fuel pressure too with the engine cold. Should be 42psi and steady.
Depress the "pin" in the Shrader valve to bleed off some (all) of the pressure. You should get some gasoline when you do this, if you care to catch it. Hook up the fuel pressure gauge and turn the ignition to "on". Don't attempt to start the car. Observe the gauge. After 5 seconds, turn the ignition to "off" and wait a half minute. The specs say 10 seconds, but I'm being conservative, here. Repeat 3 or 4 times, or until you get a good pressure reading. If the pressure comes up to specs, move on. If the gauge doesn't move, see post #2 of this thread.
RACE ON!!!
