Should I fuel inject my 350?

[Joe Link]

I have a chevy 350 in my FJ40 and I've been looking into fuel injection setups for it. It'd be nice to increase throttle response and hopefully gain a couple mpg. What're the benefits and drawbacks of FI over a carb'd engine? I'm running a quadrajet right now. You guys think I'd see much of a fuel mileage gain? I'm gettin around 10mpg city 12mpg highway right now. I've heard you can get the required TPI stuff from a GM and swap it over, but I can't find much info on what it takes to do the swap.

 

[tornadoalleycruiser]

takes everything off the donor motor, wiring, tbi unit, external pump etc.. not all that hard wiring is somewhat scary but woody has the schematic somewhere in the tech section.. i used a painless on mine and don't think i'd use one again.. i'd go with howell or someone else next time..
while your there might as well grab a serpentine assembly, why not! would take a new waterpump but that's about it..

 

[Yoda]

I did TBI on mine.

Benefits:
Runs good at all elevations
Runs good at angles
Runs good over rocks
Starts good in all temps

 

[tornadoalleycruiser]

don't forget will run upside down..

 

[fj40_rico]

I did the wiring on mine and I was worried I was going to screw up badly. but I used the schematic that woody has and the most amazing thing was that it actually ran the first time I started it.

- Rico.

 

[chief]

The only problem with running upside down is that the oil pickup cannot pick up any oil causing the engine to seize from lack of lubrication, unless you are running an inverted oil system out of an old Stearman Biplane with a 450 P & W

 

[cardinal fang]

What year is your engine and what transmission? Howell and EFI vendor on pirates have the best harness. You can get most of the pieces off ebay or through this board. If you buy a kit, that will be $$$.

 

[Joe Link]

Honestly I'm not sure what year it is. I heard it's a higher hp crate engine with about 5k on it. The tranny is a turbo 350. How much do you think it'd be to piece together a kit?

 

[80fj40]

Man thats like asking what color car should you buy ... all personal preference!

Here's my two bits:

Biggest advantage is as someone else mentioned better all round drivability - cold starts, off camber / any angle works good with FI

Fuel injection can control fuel intake at decel ... a carb simply dumps more fuel in during decel (unless you have a fancy emissions carb).

I've got an FJ40 and short box pickup, both use a Q-jet ('75). I use it beause of simplicity. Hard to stop a carburetor unless it brakes in half or something. I like carburetors because they're all mechanical - kind of like those old mechanical inline diesel pumps that never die. As a technician I dealt with a lot of drivability and electrical problems and I think that has turned me off anything that has wires attached to it.

But on my 4Runner, I've got a 4.3L V6 fuel injection for it. But I decided to go for the old TBI unit from an 89 S10 instead of a Vortec, CSFI or OBD2 fuel injection system. Again, the TBI 4.3 is soooo simple.

 

[cardinal fang]

If you buy a 'kit' from, what I have seen, $800 - $1200. That's for convertiing a non FI motor, pre 85, to FI.
If you piece it together, oh $500-$700. You can use a TBI plate adapter rather buying a FI intake manifold. Harness, $150-$300. I got a Howell harness off ebay for $150. Just luck on that deal. TBI units and computers are a plenty on the intenect or forums. Shop around and look in the classified sections of pirates and here.
I will be converting my 2F FJ40 to 350 TBI this next winter and I have all the pieces already to go, except the engine.

 

[fj40pimpmobile]

In theory would it be possible to add to my 327 sbc in my 69 fj40 a tbi setup from a chevy pickup made in the past 5-10 years? I figure if there both sbc that I could just rip off the newer motor intake manifold and everything above, swipe the harness and some lines that go to the fuel tank- any ideas on this? Is this something I could hack with obdII (OBD2 98+) for fuel injection settings? I was off wheeling today and when ever I tilt on the side my carb stops- and I have to restart a 20-30 times in a typical wheeling afternoon- Ideas on what I could take a tbi setup for a sbc model wise aswell?

 

[DaveWest5150]

the only drawback is the one that has kept me from it... If the computer takes a dump your stuck (unless you always carry a spare ) Its just one of those things, My Q jet works great... so until it doesnt... it stays.

 

[CruisinGA]

the only drawback is the one that has kept me from it... If the computer takes a dump your stuck (unless you always carry a spare ) Its just one of those things, My Q jet works great... so until it doesnt... it stays.

True... but how often does that really happen?

 

[DaveWest5150]

would you wanna be the one who finds out?
I know I wouldnt.

 

[CruisinGA]

would you wanna be the one who finds out?
I know I wouldnt.

Think about all the millions of cars on the road with electronic fuel injection...

And how often the computer just up and fails...

Most of the time, if the computer has problems it will still run in "limp home" mode.

I know in my personal experience working at a LC shop, we have never just had an engine computer "up and fail".

They may be a mystery to most, but computers are reliable technology at this point, we're not in the 70's anymore.

 

[bandy rooster]

Think about all the millions of cars on the road with electronic fuel injection...

And how often the computer just up and fails...

Most of the time, if the computer has problems it will still run in "limp home" mode.

I know in my personal experience working at a LC shop, we have never just had an engine computer "up and fail".

They may be a mystery to most, but computers are reliable technology at this point, we're not in the 70's anymore.

i'm gonna have to agree with him on this one, i've been working in a parts store for quite a while now, and i've sold exactly one ECU to date....and thats it... theres so much more that could go wrong before the ecu takes a crap on your fun...

 

[my64fj40]

Go TBI, throw a q-jet (or other carb) in the back of the truck just for that one in a million chance.

I have a carb because I have this thing against computers, but it certainly doesn't mean a carb is better.

 

[LandCruiserPhil]

the only drawback is the one that has kept me from it... If the computer takes a dump your stuck (unless you always carry a spare ) Its just one of those things, My Q jet works great... so until it doesnt... it stays.

I was also scared of FI for the same reasons. After 20 years and 176K on my SBC conversion my TBI has been flawless. Now I would not was time with a carb.
I have seen a lot more carb problems then FI problem over the years.

 

[Tym@work]

My FJ40 went through a carbed 350, Holley sucks for off-road, Carter can be adjusted but mine was still iffy off camber. I also ran the carter on the 400 small block that's in the 40 now, when the top end caught fire due to a fuel filter leak I decide rather than buy a new carb I'd do TBI since it toasted the wiring harness anyhow. Starts better, runs better off camber, uphill, downhill, idles up obstacles (partly due to the SM420). Being that the 400 small block uses the old style intake bolts I had to drill out the intake holes to bolt the stock TBI intake to the heads, and believe me if I can do this anyone can. I transplanted a stock 5.7L TBI in my FJ60 and it gets 14.3 mpg mixed driving. That's better than my firends get in their stock 60's, and better than my '96 FZJ80.

Had one problem at GSMTR last year, spent 2 days working on the rig because it wouldn't run under load, got no sensor errors but replaced several anyhow, including the ignition module in the dist. $200 later discovered the fuel line was being pushed up through the floor and pinching at a near 90-degree angle and starving the engine when it needed more fuel. moral of the story is I expected it to be something complicated with my new fuel injection set up, but it was something simple. Good news is, I have spare sensors now, heh. So don't be afraid of FI

 

[Macgyver]

dry sump baby...............

The only problem with running upside down is that the oil pickup cannot pick up any oil causing the engine to seize from lack of lubrication, unless you are running an inverted oil system out of an old Stearman Biplane with a 450 P & W