SBC Fuel Injection Decision Help! (1 Viewer)

[Mr. Notorious]

Hey guys, would like to get some feedback and start a discussion to help me make up my mind!

Background: Rebuilt '78 350 block. '78 heads. Weiand intake, carter AFB competition series carb. New comp cams EXTREME Energy 4x4 cam, with lifters, etc. Mallory HEI distributer with vacuum advance. Electric fuel pump. My goal is to be able to turn the key and go, whether it's for a cruise or hitting some rocks all day.

Options:

1) I have an older analog Holley Projection 4D partial kit given to me. It has the throttle body, the computer, hacked up harness. The throttle body appears to have only the TPS, and no other sensor (isn't there supposed to be an IAC?). So my understanding is I'd need the IAC, MAP sensor, Coolant Temp sensor; which only comes form Holley and I haven't priced this out yet. Seems like the general concensus is the 4di system (laptop programmable) is great, but my analog style is hit or miss.

2) I can get a 1990 350TBI out of a blazer for free, but the motor is bad so I'd only be taking off the TBI. Sounds like most if not all the sensors are there as well as the computer. Biggest headache I see is wiring, which would be just as much as a pain for the Holley kit since it's so butchered and missing everything. Not sure how available documentation is for it.

3) Rebuild the carb and pray it does what I want.

I'm currently replacing the entire fuel delievery system up to the carb, including the gas tank as it has rusted out a little bit. So I plan to have the new tank fitting with a return line before I put it in. I'd like to accomplish something reliable (offroad mostly) for under $300 with what I have.

I threw in a couple pics of the projection unit just incase something sticks out.

Thanks.

 

[Mr. Notorious]

Here's the Pics.

Additionally if anyone has any good sites or threads feel free to share!

 

[mophisto]

holy huge pictures batman =)

 

[fussy_cruiser]

I would do:
1) Option #2 and ebay/craigslist the holley and the carb if I wanted to go cheap. (The stock wiring harness can be a pain, ask me how I know.)

2) Option #2 with a new harness aftermarket harness (Howell engineering or Painless) would be the best if you have the ~$400 to burn. Then ebay/craigslist the parts like above.

 

[BrianSanDiego]

Hey Mr.

I have an older Holley 2D analog on my SBC.
If you have a choice you might want to go with one of the other options. Mine, and probably yours, have only a TPS, water temp, and tach input for the computer. No airflow sensor or MAP sensors.

It really is too basic of a system for good mixture control. Also on my analog system, when one of the mixture adjustment rheostats went bad the controller turned on the injectors to FULL BLAST. Before I realized why it wasn't starting the motor had started to hydolock on gas and I had raw fuel dripping out of the exhaust pipe!
Thats not a very robust and fail safe design I'd say.

That being said, I've replaced the rheostats with quality units mounted in the glove box, have the system dialed in at the moment, and it runs like a champ. But it does require contstant tweaking because it has nothing designed in to compensate for air temp or density.

A closed loop kit is available, but I think it would be better if you started out with a better system like stock GM or possibly Howell?.

Hope this helps
B.

 

[FJFOOL]

Another option might be to sell the parts you have, and have a quadrajet built to off-road specs. Pretty foolproof system, mine works awesome. Simplicity can be a good thing. Good luck with your choice !!

 

[DomSmith]

The Holley system is very basic and as Brian says takes a bit of tweaking (OK a LOT of tweaking in my case) and I was never completely satisfied with mine. After learning more about FI (which I still know very little) I would not throw any money at the Holley stuff.

Do it right... once, and be done with it.

 

[Cruiser Clint]

my .02

I have been through two stock TBI installs now, and I found it very easy to do in the end. I am average at best when it comes to electrical issues, but there is so much info available, that even I could figure it out. You should visit the FAQ on this link : InjectionTalk - Binder Bulletin Forums and read up. The installation manual of Painless Wiring kit is a free download on their site, and was also a big help. In the spring I am going to do my third stock TBI conversion on a new 350 to replace my 305, and the Painless documentation and the wiring schematic in the tech section (http://www.ih8mud.com/tech/tbi/wireTBI-1990b.gif) will be what I use. HTH.

Clint

 

[TLCSKULLS]

Another vote for the stock TBI. Easy to install, works well and easy to diagnose problems and fix them, and there are TONS of spare parts for cheap in every bone yard.

 

[UNO_RACING]

I used Howell Engine peformance's basic TBI system. It works great for non-modified motors. They have two types of TBI set ups, a non ignition controlled and ignition controlled. The non ignition controlled uses a vacuum contoled distributor. The non-ignition control system is very basic and eliminates the need for other sensors.

I would suggest springing for the ignition contolled device, provided you have electronic ignition, becasue it controls timing electronically producing much liner peformance and better fuel economy.

Because I have a modified motor, I'm thinking about upgrading to Howell's MPI system. It's less expensive than say, Edelbrock or Holley with effectively the same result.

The only thing that I don't like about their systems the programming of the prong, it has to be sent back if it's not right.

 

[Downey]

I didn't study all the comments above, but I believe the popular opinion is that you go with the Chevy TBI, not the Holley. The Holley Projection always had a bad reputation as not having good drivability. I think that's true, how could it with so few team players, pratically no sensors to give the computor information. I think you will be much happier with the GM TBI, and I wouldn't hesitate using a GM or Painless harness. Just don't let anyone talk you out of using 1,000 percent of the senders and sensors. Wiring is dirt simple---any questions, call
Jim
(562)949-9494

 

[LCOwner]

My goal is to be able to turn the key and go, whether it's for a cruise or hitting some rocks all day.

The the GM TBI is the only option then IMO. Sounds like you'll need a custom chip burned for the cam you have but most of the vendors can do that as long as you have your engine and cam specs. They can also write out the other sensors you may not want like the speed sensor. You won't need the knock sensor either if you are set on running the Mallory.

 

[cruiser enthuiser]

I just started a GM TBI conversion on my carbed 350...it also had the Carter AFB but I was never happy with how it ran and was tired of messing with it. TBI started to make more and more sense as I considered rebuilding the Carter or investing in a Q-jet, especially after reading this article:

How to install GM TBI on any Chevy V8

Mine is a crate engine with only about 4k miles on it and I think it is worth keeping so...

I took a 5.7 engine from an '88 Suburban that had most of what I needed including the throttle body, intake manifold, computer, distributor, sensors, etc. all for $100 that I found on Craigs List. I just finished modifying the four center bolt holes on the intake and it wasn't too bad and now it mounts right up to my block. I intend to get a Painless Harness to make life simple. Still need fuel pump, fuel sender with return line, 02 sensor, VSS.

In all I figure I'll have about $600 into this, maybe more. When I considered the cost of a new carb compared to the advantages of EFI, TBI seemed like a no-brainer. Good luck to you!

 

[mls57jax]

I did the Holley 4D Pro-jection analog install last spring and have had no real issues with the set-up. Actually, I love it. The instructions were simple to follow and being that the harness was complete and not hacked into, I had no issues getting it dialed in once installed.

The kit came complet (NOS, still in the box, never installed, everything there), probably of early 90's vintage, and we followed the directions to a tee. The two issues encountered were low fuel pressure due to the age of the electric fuel pump(?) and that all of the 0-rings were a powdery, rubbery mess that clogged the orifices of the injectors when fuel pressure was added. Everything on the TB leaked fuel on initial power-up. I also think I replaced the TPS a week after the installation as the resistance readings weren't what the manual said they should be.

After installing a new low pressure fuel pump and a Holley software rebuild kit on the injectors, the thing ran awesome and required little to get it dialed in. I mounted the control module in the radio slot of the center console which facilitates easy adjustment of the system (and yes, the pots only allow for minor adjustments, but they do adjust).

The engine is a 30-over 400 small block, RV cam, roller motor, yadi-yadi, mated to a 700R-4 via the old Downey 1" adapter. I modified a Lokar carb linkage bracket for the kick-down and throttle cables which has worked out well.

The Pro-jection replaced the ever faithful Q-jet and I do miss those big secondary's on occasion, however the truck will now run at any angle over any terrain without a stutter or stumble, even with stock gearing on 36" SX's. It gets trailered almost everywhere but it is street legal here in PA.

This is just my experience with the 4D system. YMMV. I'm very pleased with the overall performance thus far. It was 12 degrees here last weekend when I started the truck. It fired right up, warmed up, and kicked down to a normal idle once it warmed up. This was after having sat untouched for more than 3 months, too.

Mike in PA

 

[Markh]

Option 2 is the only way to go. Take all the TBI parts off the doner and buy an aftermarket wiring harness (Howell, Painless, ect).
Fuel injection makes life so much easier off road.

 

[Mr. Notorious]

Great feedback guys! Much appreciated! I atleast decided to can the Holley Pro-Jection kit (sorry to those with good luck). I also picked up a couple books on TPI to read about. Haven't done much research on this system yet.

In all I figure I'll have about $600 into this, maybe more. When I considered the cost of a new carb compared to the advantages of EFI, TBI seemed like a no-brainer. Good luck to you!

How much was the Painless harness? Have a decent breakdown with prices for what you purchased? I'm sort of concerned about the programming prices. I see they even make the adapter plates now for a a four barrel intake.

I just have to look up if the computer for the donor motor I have is the right one I need.

Dumb question, but after this TBI swap, the check engine light will work and tell me if somethings wrong like a modern vehicle correct?

 

[Markh]

Great feedback guys! Much appreciated! I atleast decided to can the Holley Pro-Jection kit (sorry to those with good luck). I also picked up a couple books on TPI to read about. Haven't done much research on this system yet.

How much was the Painless harness? Have a decent breakdown with prices for what you purchased? I'm sort of concerned about the programming prices. I see they even make the adapter plates now for a a four barrel intake.

I just have to look up if the computer for the donor motor I have is the right one I need.

Dumb question, but after this TBI swap, the check engine light will work and tell me if somethings wrong like a modern vehicle correct?

The Painless TBI harness is $390.00 from Jegs, the Howell TBI harness is $325.00 from Howell. To me the Howell harness looks cleaner.

The check engine light will be part of the harness and will tell you if there is a problem.

Howell will be able to burn an e-prom for you once you give them ALL the information about your vehicle, and engine. I'm not sure how much that runs. But they'll want to know everything about the engine, transmission, rear end ratio and tire size.