Engine Management System

I've been doing a little reading on Engine Management Systems. Does anybody have experience with them? When are they really necessary. I have a Chevy SB 350 that I'm thinking of building up with fuel injection at some point. I was pondering getting a closed loop EMS to do it. It would go in my '84 transam. It originally came with a carburated 305 5.0 HO. Its computer isn't programable but you could get a chip burned if you installed the necessary sensors. Could you share you experiences with EMSs and opinions on when you should use them and when you shouldn't. Thanks. ---Rich

Well in an 84 vehicle your stuck with using all the stock cumputer system & sensors and all the stock emission controls or it will not pass a smog test.... unless your somewhere they don't do the test (YET )

Of course, switching the engine will make the smog nazi's scream. Companies like Edelbrock sell complete EFI systems that include the intake injectors, throttle bodies, etc. It also includes the computer hardware and software.

Although I'm not really concerned with it here you can totally pass all the smog test crap. There are a ton of systems that have the OE rating. Probably test even better than it does now and get better gas mileage. 350s were also offered in firebirds so the swap isn't an issue. I'm using my car as an example but am talking in general. What applications is it advised and where isn't it the best solution? More importantly I'd love to hear and stories good and bad about doing it or making a decision about it.

You can get a version of Edelbrocks for almost any popular engine family.

Installation isn't that hard depending on how the computer is set up. A friend of mine installed a Holly set up (before they were bought out and this line was discontinued) on his '79 Bronce with a 351W. Had it running in a day. It was set up like a 4 V Carb, but with injectors. The computer on that model didn't require a laptop to program, but since then most systems are more precise.

Because of the engine I'm using in my Studebaker (6.0L), I'm using the OEM ECU.

Hmmm...I think everybody is kinda not getting the question. I've built a 305 and a 350 in the past year. Both were carburated without any kind of computer. Now I think I have most of the mechanical theory and practice down (although I'm no expert), I'm interested in getting into the computer controlled high performance aftermarket systems. I certainly appreciate the responses but I know I can get a chip burned or go with an EMS 3rd party stand alone system. I'm simply looking for anyone's stories on specifically installing an EMS and their decision process with going with it or deciding against it. Systems like TEC3 or Motec or Haltec and SDS. Again my 3rd gen F body is just an example. I find these systems interesting and want to hear about them in your hot rod, late model, boat, plane or whatever. By the way I have a few laptops and like programming although these systems are more fill in the blanks than programming.

Ok, i think i get what your saying. Computer assistance systems are really for EFI systems. If your getting into that style of car, you will be able to either use the factory system which will either reboot itself for the new data, or you will will have to modify it with a chip or a new system. As far as aftermarket comp systems, you may want to look into companies like MSD. Or you can wipe the entire factory system and write an entire new program. Not easy to do, but if your familiar with Assembly, it can be done.

JerseyRodder most of the rodders on this forum seem to be staying with the carb, and a lot of them still have the point system, and what they run is their bus., but you wont get a lot of info. off of this forum about EFI. i run it on everything ive had for a long time now and wouldn't have it any other way, but not because its better or anything. i work on computer cars everyday so i like the idea, but i think you should run what ever you wont. i think the biggest factors is if it brakes down do you have to pay someone else to repair it for you, that could get costly. most people can put in a set of points or bolt on a carb., but with a computer car if it brakes down you will need a scanner (and the knowledge to use it) or carry the car to a shop. i got my lt1 with the wiring harness out of a junk car 4 yrs ago and haven't had to do anything to it, but change the oil and ive driven it about 25,000 miles. its like its all ways been, with the points and carb.there is always something to do to it, but most people can do it. with the computer if its right its almost mantance free, but if it does brake down then you got some major problems.


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I'll agree with LT1S10. You won't a lot of info on this board regarding EFI. To many here, an MSD box is hi-tech. My decision to use EFI for my car vs. Carb comes from past experience. I've found that, to me, the EFI is easier to deal with. Since 1986, I've only had one car with a carb (Carter 1-bbl). I've had good success in diagnosising my own problems without major drama, and repairs were more along the lines of plug and play.

My original plans for my Studebaker with for a 350 Chevy crate motor with a 4-bbl. Since then, I've really liked what I've seen with the new GM LS engine family. I decided I wanted to run a roots blower on the engine. EFI is the best way to tune this type of system, and this engine family has excellent support from the aftermarket already. Using a program such as LS1-Edit and a laptop computer, I can set the computer up as conservative or wild as I want.

As many guys who've run LT1's have switched EFI systems from OEM to aftermarket stand alone units. I'd check on a board that deals with LT1's.

Well heres my take on it. EFI is the best thing to happen to the automobile since the rubber tire, being a master tech and specializing in emissions & drivabilty problems I haven't had to spend half my time adjusting chokes at every season change, I haven't had to run service calls on ice cold mornings too pull spark plugs and burn em off in driveways so the frantic owner can get to work so they don't loose their job. etc.etc.etc.... I love the OBDII systems(96 up) and ain't nothing cooler to me than fixin the one thats been to 10 different shops. As little as 15 years ago it was very rare to see a vehicle go to 100,000 miles, but nowdays it's common place to see 200,000 or more
and I can only contribute that to the EEC systems. Now about the aftermarket systems, I gotta admit I don't know much about em,I know Holley had one they discontinued because it had problems but the problems probally stemmed from the users not having enough knowledge to set em up & maintain em properly.But let me say this,if I built another rod with a closed engine bay it would for sure have an OEM type of EEC system.As of now my little coupe is running a 3 duece rochester setup cuzz thats the look I was after,I really wanted to go with Moons new 3 duece injection setup and was pretty impressed with it, but being the cheap S.O.B. I am,just couldn't justify the cost,specially when I think I can build the same sorta set up myself,but that'll hafta wait for the time being.....