Advice on 79 Monte fuel injection conversion

[79CMC]

Evening Gentlemen (and ladies)

Thanks for this wealth of knowledge ya'll provide. My query concerns my carb'd 305 79 Monte carlo. I want to drop in a new 350 and the more I think about it, I want it it to be fuel injected for efficiency and dependability. I don't need a speed demon; I just want a reliable daily driver. What package/type of engine (ex: LS1) would ya'll recommend? I'd prefer crate or reliably rebuilt, mostly for the peace of mind and the fact that the machine shops in my area are slow and already backed up.
How should I go about installing/hooking up the peripherals? Is it easier to get a generic computer and wiring harness or rather get an ECM specific to each engine? It may be beyond my means, so going to a shop is a strong possibility. I'm not well educated about FI systems. Thanks for any advice and suggestions you have.

 

[85 Cutlass Brougham]

Well, let's just say it's expensive if you know what you are doing and VERY expensive if you don't. If you know what you are doing, you can put in a complete take out from a Camaro in TPI, LT1 or LSX format with a modified oil pan if you go LSX. If you do that, pretty much every one of these options will require a ECU rework to get around the chipped ignition key, or a swap to the F car's ignition lock and miscellaneous parts. If you KNOW what you are doing, you can run a junkyard TPI in speed density format using a stand alone like the Megasquirt (comes in unassembled kit form-solder your own ECM!!!), Greddy Emanage, or Spectre EMS PRO (assembled Megasquirt). If you are ambitious and have cash, then you can run a Motec, but that is not really necessary on a street car. Expect to put $500-$1,000 in the cheapest EFI system if you know what you are doing, or $50-100 in the cheapest carburated fuel system. Yes, EFI has benefits, but a well tuned Quadrajet will be within 1-2 MPG of EFI and just as drivable in every way except for cold starts. I have about $60 in my fuel system that is composed of used components including a junkyard Quadrajet off an old Chevy van, an Edelbrock Performer intake, and a Holley fuel pump. It's dull, but cheap.

Now, for the cheapest EFI Gen I SBC install, you could use a 1985-88 ECU (no chip in the key), a used TPI intake and injectors, a fabricated air intake using PVC pipe, a Grand National or 4.3 V6 Monte Carlo fuel tank with a Camaro fuel pump (needed for the baffling), bend your own fuel lines or Push-Lok hose and fittings, Camaro wiring harness (should put the computer pretty close to the stock location), small HEI distributor, and a complete serpentine accessory set complete with reverse rotation water pump. Sprinkle in a few new sensors and oodles of time to chase gremlins in a 20-25 year old EFI harness, and expect to pay $750. Replace the GM harness and ECU with a Megasquirt and expect to add on another $200-300-plus several days/weeks/months/ (years?) to figure out how to make it work and program it with a laptop. Honestly, it is not a project for the first timer or someone who does not love to tinker. Paying to have it done by someone else could easily exceed the price of just buying an LS1 F body in good condition to begin with. This is not to discourage you, but to give you some idea of what it takes. I happen to love to tinker with all sorts of crap. My house is littered with mechanical and electronic items new and old in various states of repair, yet I have decided not to do this to my car. It is just too expensive for the benefits you get in return. My advice is that from a purely practical perspective, if you want to save gas and have reliability, get a small Civic, Sentra or Corolla with EFI to drive every day and just use the G body on the weekends. In the long run this will cost you less money, and the price of the beater will be less than the price of the EFI conversion for a novice. Plus, if you decide you want to experiment with injecting the G car, you now have a parts runner/daily driver and can take your time figuring it all out without the fear that you won't make it to work or school the next day.

 

[Blake442]

X2!

We had some epic problems trying to trouble shoot a Holley ProJection system we put on a car we built at work. Dicked with it for months, and ended up putting a carburetor on it. What a waste of time that was.

As far as reliability and efficiency goes, my '79 Malibu with a 2bbl carb started everytime with one pump of the gas to set the choke, even in -35* weather. It ran like a top, and got a consistant 20 mpg. And this was a 267 V8 with over 200K miles on it.

Properly tuned, a carb is just as good as efi.
Worn out and misadjusted carbs give the rest of 'em a bad wrap...

 

[Doober]

Another option you could go with is a fuel injection harness/computer from a 4.3 TBI Monte Carlo, use the tank and plumbing for the same car, and get a TBI 350. That would likely be the simplest route to go. The TBI heads weren't excellent performers in stock form, and didn't have a very large power band. A remedy you could use for that is to run a set of Vortec heads with a TBI-specific intake from Edelbrock. This will keep things fairly simple as far as wiring and EFI terms go (no adapting for other types of intakes, TPI, etc.), and it should still be a fairly decent performer. You could also probably add a mild computer compatible cam to wake it up a little bit, and it would be quite a bit of fun to drive

Like 85CB said... unless you know what you're doing and only go for a stock TBI 350, you're gonna spend some change. A TBI motor with Vortec heads will put you above a plain stock TBI motor for sure. Even if you just buy the 350, put the Votecs on, bolt on the Vortec/TBI intake, hook everything up and go, you're still probably going to spend upwards of $1,500 since you have to plumb the EFI system, and that's if you did all the work yourself (using new lines of course... I wouldn't chance anything with any lines you may already have).

Here's my setup...
'88 350 (already had the engine, so that was a bonus)
Vortec heads
Comp XE268H cam
GMPP dual plane Vortec intake
600cfm Edelbrock carb.

The only new part in that whole setup is the cam. I also used the fuel pump that was on the 305 that was in the 'Bu and haven't had any issues (it had been replaced sometime recently before I got the car). Driveability is great, the only time I have any issue is when the engine is cold (takes a few minutes to warm up, I took the choke off since it wasn't electric). During the summer, even after the car sits all night, I could go out, flip the key, and it would fire up just like any EFI motor (actually better to be honest... click here to see what I mean, THIS is actually how the car idles, idle in the other video was set a bit low). I didn't do rings on the engine (hence why it's back out right now), but that would've only added $35-$50 to the total build price. Other than that I don't think I spent more than $700 on the entire build (gaskets, new oil pump, new cam, new main bearings, paint, cleaning supplies, etc.). My point here is you could take a mild carbed 350 and have some fun with it, and have a stock EFI driver for year-round if that's possible, basically the same thing 85CB said (I know some people live in apartments, etc.). Granted it's ultimately up to you, it's just a suggestion. I guess my thoughts on EFI (unless you have a car that already has it) are to go with an LS motor. You'll spend a bit more than on a Gen I SBC, but you'll be happier. A stock 6.0 probably makes as much power or more than my engine currently does, all with a stock cam/tune.

 

[yourownself]

i plan to do an LS swap, myself. brp hotrods sells a kit to make the LS swap a painless endeavor. check ebay, craigslist and local scrappers for a line on an LS motor cheap.
i had found an LS1 camaro for 600, but i was a few minutes too late. other than that i've been looking at an LQ4/9 out of a truck. more towards the LQ4, just for the fact that you have to run premium in the LQ9. i've also been heavily considering waiting around until the 6.2 VVT motor is a little more affordable.
here's some links to help you research the LS swap.
it's really the only swap that makes any sense to me.



http://www.montecarloss.com/community/u ... 161&page=1

www.brphotrods.com

www.mastmotorsports.com

 

[79CMC]

Wow thanks for the quick and detailed responses. Oddly enough, I do have a civic that I drive around school daily. I go to Virginia Tech, and the weather around here requires a reliable car (plus it's about 300 miles from home, and 35mpg ain't too shabby). My Monte is my project car, but I'm commissioning as a 2nd Lieutenant in the Marine Corps when I graduate in May. A slick 79 Monte definitely embodies an Officer of the Corps a bit more than a tinny civic (no rice).
The only reason I was considering fuel injection was because my initial training will take place in Quantico, and then if I get Infantry like I want, more of my training will be there. Like I said, Virginia weather requires a reliable car. Also, who knows where I'll get stationed or what the climate/elevation will be. I just don't want to have to go out in a hurry and not have a car that starts up on command. My dad knows a ton about cars and actually has his own shop, and he's a fan of the carb'd version himself (mostly due to the simplicity and his old school ways). Seeing as many of you support that route as well, I will definitely re-consider it. It is much cheaper and easier for a newbie to tinker with...I just want to do the best I can while I have her under the knife. Also, I'm looking to spend about 5-8K more to completely overhaul her (engine, paint, some interior), if that factors into your advice. Thanks again for all your input-it's much appreciated.

 

[85 Cutlass Brougham]

The sad thing is that this hobby has become disturbingly expensive as of late. Even if you really know what you are doing and do all of the work yourself, the costs of PROPERLY building a car can easily exceed $10k for a mediocre G body. Yes, you can cheat with a very cheap paint job, keeping the old weatherstripping, no A/C, etc. and get away cheaper. However, doing good paint (expect to spend $800+ for a good paint system-just for the paint), upgrading the brakes and suspension, a decent interior and the minimum options of A/C and a reasonably good stereo will cost you plenty when you add in all the little things you can't anticipate. G bodies are old cars now, and as such good used trim parts are no longer easy to find in junkyards. The parts you can find that are good used or reproduction are expensive. I have a large store of this stuff for my Cutlass that I have accrued for years, and do 99% of my own work, but even with that I am still not going to come in under $12,000 for a very average build.