Pre-Vortec EFI

OUMike · September 30, 2003

Hey everyone. Saw a local school district pickup today. By the looks of the dash it was definatly older than mine (94) and on the tail gate it said "EFI". What motor would that be?

holderp · September 30, 2003

I would say that it had a good ol Chevy small block (Gen I) with throttle body fuel injection.

99-2door · September 30, 2003

It was either a 88 or 89 TBI truck. Back in the day they were still proud of the fact that they had electronic fuel injection. Almost every vehicle from the period has a badge with some sort of FI note, even though nearly every car in production had some sort of EFI by then making it nothing special.

SilveradoWV · September 30, 2003

My dads '91 had EFI on the tailgate. It was a TBI 350!

99-2door · September 30, 2003

My dads '91 had EFI on the tailgate. It was a TBI 350!

You're right,

It was more years than just 88 or 89, but it does not denote engine size at all. I have seen trucks that say that with 4.3L and 5.0L too.

SilveradoWV · October 1, 2003

Yeah I think it was on all tailgates between a certain number of years.

plrod · October 1, 2003

88-95 are the tbi years, Vortec FI started in 96; I took it off my 89 when I had it painted, represents the fi system not the engine size.

MCourson · October 1, 2003

My grandpa has an '89 F-350 an it has an EFI emblem on it. At least the sticker is easily removed.

Sierra and Jimmy · October 1, 2003

My 88 Chevy 1/2 ton 4x4 had the EFI decal. I had the 5.7 (350) liter engine.

My 91 S15 Jimmy has the "4.3 Fuel Injection" emblem on the tailgate. Thats pre-vortec. Throttlebody injection.

OUMike · October 3, 2003

yea but TBI isn't EFI. Thats kinda strange. TBI is more like a mechanical fuel injection. So does that mean chevy kinda fibbed?

MCourson · October 3, 2003

TBI is EFI. There is even a fuse for the injectors.

99-2door · October 3, 2003

yea but TBI isn't EFI. Thats kinda strange. TBI is more like a mechanical fuel injection. So does that mean chevy kinda fibbed?

Nope, TBI is definately Electronically controlled fuel injection. Take out your glovebox liner and you will find the ECM behind it which directly controls the 2 fuel injectors in the throttle body assembly. Basically the same system from 87-95, few minor differences.

OUMike · October 3, 2003

ok...so I need help. If my TBI motor is EFI, what is the big stink about a 350 motors vs. Vortec 5700? Wasn't the major difference the method of injection? Can someone point me to a reference that has the differences between the 210hp V8 and the 255hp Vortec?

MCourson · October 3, 2003

Vortec is a completely different induction system from the air filter through the heads. I'll let someone else who knows better explain the ins and outs.

plrod · October 4, 2003

Starting in 96, when the vortec motors were introduced the fuel injection system changed to Vortec fuel injection which is basically one injector per cylinder. These motors also have Vortec heads which I'm not exactly clear on the differences with the prior version heads, I do know that the head design is different from prior engines as a TBI manifold will not bolt up to a Vortec motor. The bolting pattern is different. GM does have available a TBI manifold to bolt into a Vortec motor, I actually have one waiting to put a 97 motor in my 89 TBI truck one of these days, I've been contemplating this project for quite a while and just have to make the time to do it, if I ever do it - my old motor is still holding up ok. Vortec I believe refers to the fuel injection system which sprays a Vortex (tornado type) mist of fuel into the cylinder which theoretically is more efficient because the fuel is dosed more efficiently. So Vortec heads along with Vortec fuel injection yields the higher HP rating. Someone correct me if I'm wrong.