9th injector -1989?
Thread Starter
Acct suspended by request 12 Dec 2012
Joined: Sep 2007
Posts: 94
Likes: 1
From: Louisville KY
9th injector -1989?
Hi folks, i have an 89 L98 and it is VERY rough until it warms up about 5 minutes or so iding. Does the 89 have the 9th injector and does this injector pulse for a while while the car is cold?
Thanks!
Gary in Louisville
Thanks!
Gary in Louisville
Thread Starter
Acct suspended by request 12 Dec 2012
Joined: Sep 2007
Posts: 94
Likes: 1
From: Louisville KY
Hey thanks Fred! Apparently the 89 computer just extends the pulse or something when the engine is cold to richen the mixture. I am removing the plenum now and am going to take my injectors to work to check flows, spray pattern, etc and clean them. So I hope that turns up something.
Melting Slicks
Joined: Apr 2002
Posts: 2,118
Likes: 0
From: St. Charles, MO Route 66 Corvette Club
wa4ky: I just read another post of yours where you are removing the injectors from your 89 for cleaning. While you have 'em out, measure the resistance of each injector. Cold resistance spec is 16.5 +/- .3 ohms. Good injector coils will have all eight ohm readings very close to same value. Readings below spec indicate the coils are starting to short out. Do a search on Multec injectors and you will find a lot of material on this. Hope this is helpful to you.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
You should also scan it. The Coolant Temp Signal is used like a choke - the colder the coolant temp, the longer the ECM keeps the injectors opened to fatten up the mixture and the higher the targeted idle speed. You need to see what that signal is with the engine off (should be close to the air temp). Then start it and observe how it increases as the engine warms up. You can also compare it with your Dash read out - #'s should be close. Note Targeted Idle and Actual Idle also.
