nsnyder
9/11/2007 1:58:24 PM
i want to change over from cpi to tbi. Does anyone know what is needed
swartlkk
9/11/2007 6:20:34 PM
a different truck...
Seriously though, it would help to know what you are working with...
Hanr3
9/12/2007 11:33:43 AM
The simple answer is the intake manifold, sensors, and a new fuel pump. To get more specific, we would need to know more about your plans.
SirLDragon
9/27/2007 5:59:00 AM
I'm new here but I was told that you cannot bolt the CPI manifold to TBI heads. Something about the angle of the intake bolts being different. Also, all the sensors will be different.
Hanr3
9/27/2007 6:26:46 PM
That answer depends on the year of the truck, not the CPI/TBI/fuel injection system.
In '95 GM changed the angle between the heads and intake manifold. Intakes prior to '95 can be swapped on engines prior to '95. Intakes after '95 can be swapped on engines after '95. You cannot swap intakes prior to '95 on engines after '95 and vice versa. That is hte simplified version.
nsnyder
9/28/2007 7:38:57 AM
its a 95 odb2. i heard the tbi and the ssei get more power and better mileage than th cpi.
swartlkk
9/28/2007 8:06:36 AM
I think you meant scfi, not ssei. Well, the scfi motors (96+) are more efficient. The some of the CPI motors have the highest rated hp & torque of all of the fuel injected n/a 4.3L motors, but I believe that the SCFI motors have higher average HP and torque than the CPI. The TBI motors were known to have good torque, but were limited in the HP realm.
And a '95 isn't really OBD2, but it isn't OBD1 either. It is a hodge-podge of the two commonly referred to as OBD1.5.
nsnyder
9/28/2007 12:50:59 PM
are the scfi heads the same or are the bolts diff?
swartlkk
9/28/2007 1:03:19 PM
The intake bolts are different in the SCFI head when compared with a pre-95 CPI motor.
nsnyder
9/28/2007 1:04:44 PM
so the intake bolts are same thanks
swartlkk
9/28/2007 1:13:33 PM
Yes, to your '95 motor, they should be the same. Please put your vehicle information in your signature and attach it to your posts so questions can get answered more clearly.
SirLDragon
9/29/2007 6:56:14 PM
quote:
ORIGINAL: Hanr3
That answer depends on the year of the truck, not the CPI/TBI/fuel injection system.
In '95 GM changed the angle between the heads and intake manifold. Intakes prior to '95 can be swapped on engines prior to '95. Intakes after '95 can be swapped on engines after '95. You cannot swap intakes prior to '95 on engines after '95 and vice versa. That is hte simplified version.
Ok, that's completely off from what I've been told prior to this. And kind of confusing since the CPI ("W" code Vortec) intake is the same from '92 to '95. Or is there a difference to the inside of the lower plenum where the bolts are?
Hanr3
9/29/2007 10:08:05 PM