I am getting into a huge debate with my friend, who want to cconvert his 350 to fuel injection. Right now he can afford the 2bb holley proinjection kit (which I think he should buy), but someone else is trying to convince him to go with edelbrock's new MPI system. The thing is that this edelbrock system is 3 times the price. Sure it comes with a intake manifold (proinjection just uses the stock one), it is multi-point and has exterior controls, but does he really need all of that on a stock 350, that he is using strictly for off-roading? Is it worth the extra dough?:confused:

Thanks for any help,
Chris

If he uses one of those TBI type fuel injection setups that bolts on top of a regualr manifold he may as well just get an edelbrock carb (carter AFB) or a quadrajet, which will work just fine on serious inclines.

To really get the benefits of fuel injection, in terms of power, you need to get away from a wet flow manifold and got to a port injection setup so the manifold is dry flow.

Personally I would retrofit a Stock GM tuned port unit, you can get what you need all day off of ebay.

The Edelbrock MPI is a good unit but even the dealers will agree they are a bit behind the technology curve.

The Holley unit is okay but from what I hear the software is a bit limiting..

On a stock 350 the TPI would be almost a bolt on with just the cost of a new PROM to make it all work.

TPIJeep, if we were to go with the stock tbi, what is involved, and what is needed?
My friend tried converting his 4.2l to tbi using the ccomplete FI and cpu system. He started it last year and still doesn't have the thing working well yet. Will we have the same problems with this setup?

Thanks

This is a no-brainer. Stock GM tbi or tpi would be the trick.

You can still put a holley sticker in your window if you want people to think you're cool.

Squash

Originally posted by nakona
To really get the benefits of fuel injection, in terms of power, you need to get away from a wet flow manifold and got to a port injection setup so the manifold is dry flow.

I disagree. Not only will the steep angle issue be resolved, he'll experience better driveability, more economy (with an O2 sensor), better diags, and probably more performance. (over a carb)

Factory TBI works well, and I, too, recommend the TPI. It looks cool, works well, has tons of aftermarket support, actually increases power and you can gethelp with it here or thirdgen.org in a major way.

Bryan

If you are just looking for good off road performance for crawling we've had good success with the new geration of holley projection with the closed loop kit. It goes on in a few hours is complete and works well. I wouldn't give a plug nickle for an early projection the computers were junk.

I have to agree on the TPI. You can find them really cheap and if you have a problem with harnesses try: Chevy Thunder (http://www.chevythunder.com) Drop Leonard an e-mail, he has great prices on harnesses!!!!!! Tell him I sent you(Michael Longley). ;)

I would recommend TPI. Should be able to get a good price on one now. TPI is good for torque but above 5000 rpm it can't flow enough air but this shouldn't be a concern in a Jeep. Scoggin-Dickey is making a TPI manifold that fits Vortec heads. The Scoggin-Dickey TPI Vortec manifold and the plenum chamber, runners, and TB off an old TPI, with the Votec heads, and Ram Jet cam should make for some great torque numbers

I run a LT-4 and it's great.

The retrofit to the TPI on an older, pre 87 head is not hard at all you only have to slot the center 4 bolts, took me like 10 min with a die grinder.

You should not have any trouble with the swap, but for best performance you need to get a custom PROM burned cost is 140 bucks at most places like. www.jimsperformance.com

Most likely the problem with the 4.2l swap is the prom is looking for some component that is not there, sound like he needs a reprogram.

An aftermarket harness will run you about 295 and I have seen full TPI setups go for 400-500 on ebay.

Good Luck

GM TBI or TPI. Perferably for cost and simplicity, the TBI. The Holley and Edebrock are too expensive for what you get.

Bring it here, I could install a TBI conversion in my sleep.......

TUNED PORT INJECTION ALL THE WAY!

It's bad ass and has low end torque out the wazoo, perfect for rock crawling.

CJ

We just ripped out a tpi unit off a 305 TA, today!:cool: How much work will be needed to put it on an older 350? Will the prom need to be changed, since it is a 350, not a 305?

Thanks again guys!
chris:D

Have you checked with http://www.howell-efi.com/ They sell a GM TBI complete for the same price as the Hogly pro indigestion.

Originally posted by littlejackass
We just ripped out a tpi unit off a 305 TA, today!:cool: How much work will be needed to put it on an older 350? Will the prom need to be changed, since it is a 350, not a 305?

Thanks again guys!
chris:D


You are going to have to slot the 4 center bolt holes on the intake to make them line up right, older heads are drilled at a different angle. If you can figure out what wire goes where on the factory harness go for it, you will need to get your PROM burned for the different motor specs and the stuff you dont need like the EGR, VATS(security) ect.

Enjoy! :D

If your putting the TPI setup in something other than a camaro/firebird....I highly recommend the Painless Wiring kit. It is definately painless. I had mine wired in under an hour. I got my custom chip from Troy at Howell, very good service, couldn't be happier.

CJ