timing cfi 82 Z28
Thread Starter
Member
Joined: Aug 2009
Posts: 195
Likes: 0
From: Chicagoland south suburbs
Car: 82 Z28
Engine: 350
Transmission: Turbo 200C
Axle/Gears: 3.43
timing cfi 82 Z28
on my distributor theres a line as well as on the intake. is there anything else special that i need to do to set the timing on a crossfire? also the idle picks up and drops constantly. is this due to needing the timing adjusted?
any help works thanks
any help works thanks
Supreme Member




Joined: Jan 2009
Posts: 2,313
Likes: 115
From: belle fourche,s.d.
Car: '82 z28
Engine: L83 5.7
Transmission: 700r4-1985
Axle/Gears: 3.42 posi
Re: timing cfi 82 Z28
there is a plug in the underhood wiring harness that
has to be disconnected to put the EST in "bypass"mode
once in bypass mode adjust the base timing in the
usuall manner and reconnect the plug to resume ECM
controlled timing advance.BTW that is a single wire plug
that is dissconnected-my crossfire is modified some
from stock and that plug is not in stock location on
mine-i'll see if i can find out the stock location
has to be disconnected to put the EST in "bypass"mode
once in bypass mode adjust the base timing in the
usuall manner and reconnect the plug to resume ECM
controlled timing advance.BTW that is a single wire plug
that is dissconnected-my crossfire is modified some
from stock and that plug is not in stock location on
mine-i'll see if i can find out the stock location
Supreme Member




Joined: Oct 2000
Posts: 3,160
Likes: 777
From: Park City, UT
Car: '92 Corvette, '89 1/2-a-'Vette
Engine: LT1, L400
Transmission: ZF6, T5
Axle/Gears: 3.45, 3.31
Re: timing cfi 82 Z28
Wire is tan and should be located near the rear, passenger's side of the engine. This is for when using a timing light and setting to a spec. So you know, the factory timing spec (0* IIRC) is extremely conservative, and costs you both power and fuel economy. "FEED IT WHAT IT WANTS". I would start at 6*BTDC and advance it furthe, from there until you get detonation, then back off slightly.
I doubt that your idle symptom is timing related. If I were you I would test to see if fuel pressure is failing. Fuel pump is statistically one of the most common problems on CFI cars, specifically. If fuel pressure checks out O.K. the next most common ailment IMO, is vacuum leaks, so I'd start looking for vacuum leaks.
My bet? Fuel pressure is down. Should be 9-13 PSI and every CFI car that I have worked on "wants" closer to 13 for best results.
My bet? Fuel pressure is down. Should be 9-13 PSI and every CFI car that I have worked on "wants" closer to 13 for best results.
Last edited by Tom 400 CFI; Apr 19, 2012 at 03:44 PM.
Thread Starter
Member
Joined: Aug 2009
Posts: 195
Likes: 0
From: Chicagoland south suburbs
Car: 82 Z28
Engine: 350
Transmission: Turbo 200C
Axle/Gears: 3.43
Re: timing cfi 82 Z28
Wire is tan and should be located near the rear, passenger's side of the engine. This is for when using a timing light and setting to a spec. So you know, the factory timing spec (0* IIRC) is extremely conservative, and costs you both power and fuel economy. "FEED IT WHAT IT WANTS". I would start at 6*BTDC and advance it furthe, from there until you get detonation, then back off slightly.
I doubt that your idle symptom is timing related. If I were you I would test to see if fuel pressure is failing. Fuel pump is statistically one of the most common problems on CFI cars, specifically. If fuel pressure checks out O.K. the next most common ailment IMO, is vacuum leaks, so I'd start looking for vacuum leaks.
My bet? Fuel pressure is down. Should be 9-13 PSI and every CFI car that I have worked on "wants" closer to 13 for best results.
I doubt that your idle symptom is timing related. If I were you I would test to see if fuel pressure is failing. Fuel pump is statistically one of the most common problems on CFI cars, specifically. If fuel pressure checks out O.K. the next most common ailment IMO, is vacuum leaks, so I'd start looking for vacuum leaks.
My bet? Fuel pressure is down. Should be 9-13 PSI and every CFI car that I have worked on "wants" closer to 13 for best results.
Thread
Thread Starter
Forum
Replies
Last Post
CarGuyDennis
Organized Drag Racing and Autocross
137
Dec 6, 2016 11:02 PM





