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Hey there ETCG fans, long time follower, first time posting. I’m a big DIY type guy and have a ’77 Olds Cutlass Supreme with a 350/TH350 back home and I wanted to convert it to TBI. It has 90k original miles on the engine and the rebuild kits are $500-$600. Does anyone know how much it would cost/how hard it is to convert the stock manifold to fuel injection? I wanted to do something like this for her. Car craft budget diy efi
If I can keep the costs down with the right injectors (not going for performance just a resto-upgrade) and keep my budget to <$2000 to rebuild/convert it to EFI, I would do that instead of just outright buying a new crate engine. (A chevy 383 440/450 is $2295 in this JEGS catalog). And upon doing more research, I think the fuel rails just need to be drilled/tapped/welded into the intake to accommodate the injectors. You think a shop can do this for me while I am getting the engine rebuilt? I would rather take a few engine rebuild classes so I am more comfortable with performance building later on.
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EFI is a tricky lil son of a gun. Your first option is a standalone TBI system. They are under 2000 often and they support more power for the future (always important). Option 2 is a stock TBI system for a Chevy 350. They only support stock or damn near stock performance but they are plentiful. Hell you can just buy a donor truck for 1000 bucks and swap everything over. Option 3 is just to stick with the carb. A properly tuned carb will start just like fuel injection and sound so much better when those secondaries open.
Well i’ve completed my rebuild and I was able to successfully drive from CA to WA. Since in WA it doesn’t need to be smogged, my mechanic and I decided not to hook up the smog equipment and plug as much as we could. So you can imagine the frustration converting a California smog equipped setup with all the hoses and smog pieces that literally fell off or were rotted through. This car made the trip but I know im missing a lot of power and maybe even plugged/hooked up vacuum tubing incorrectly (my distributor vacuum advance wasn’t hooked up till mid-trip when I noticed a racing idle). I’d almost rather be done with it and build my own TBI setup since I have not found a place here in WA that can tune or rebuild a carb or help me complete the carb’d setup. With the weather here I think the TBI setup will be superior. And no offense, you must not have read the DIY EFI article that I posted from car craft-not much need for a donor car. I already got a chevy truck throttle body for $50, and I will get the other parts slowly. Just need this carb running right for the time being :/
Why don’t you buy a carb tuning book and get to fiddling. Thats how I learned. A stock 305 isn’t going to need a ton of fuel. The reason I bring up donor truck is you’d have a computer and injectors sitting there already. Plus you could get an overdrive transmission if yours doesn’t have one already.
I recently started watching a few quadrajet rebuild videos, and my idle is doing a lot better. I know I will have to rebuild it-there are about three major problems I noticed. I guess its more of the conversion between a smog car to a non smog car (what to keep/what to plug). There is really not a set of steps to follow for that kind of conversion I found for my setup yet.
That and there are just so many reasons to convert it to TBI before winter I would feel like im wasting time and money rebuilding the carb if im going to replace it anyway. Thats the only reason why I haven’t put much effort into it yet.🙂 While it would be nice to be able to have TBI on a older GM auto, why do you want it ? The type of TBI that would work for your engine type and model year is a crude early version that uses a carburetor body and has two injectors mounted on top of the carb body. This was the state of the art from GM in the early 80’s, and now what you are wanting from your post, You would like a sequential fuel injection mounted in the intake, and that will require a lot of both, money and adaptation. I believe Holley makes a kit to install, I found one on the Jegs website. Just go to the Jegs website and in the search window type in TBI IINJECTION KIT. and it will lead you to a kit that will mount on your engine and may require a new intake plus the price of the kit, around 1500 to 1600 dollars. If you really want fuel injection, this is the way to go for that option. Good Luck.
Well basically slotcar, I have 3 major problems with my current carb. 1. The vacuum lines aren’t routed correctly. It used to be a California smog equipped car, and a lot of the stuff was either rotted through, or rotted off. 2. The air horn doesn’t work. 3. The secondaries aren’t opening up. They’re not stuck shut, they work mechanically fine. I think it has something to do with the linkage on the drivers side after watching a couple of videos on it.
With that said, a rebuild is in place. This is a daily driver and shops in the area don’t know how to work on carbs. Looking at the smog mess really drives them away cause they think i’m trying to do something illegal. After working for 10 hours a day, I have about 1 or 2 hours to myself. So if I wanted to take it apart, it’d have to be over the weekend for sure…but I also can’t screw it up, I have to get to work. With a TBI setup (and no, im not going for the GM unit they had in 1977 on the Oldsmobile equipped Cadillac Sevilles-the first post in this thread has the link for the DIY mega squirt :stick:) I can do away with all the carb issues. I can have better gas mileage and easier starts in this harsher state. A few extra ponies wouldn’t hurt either.
The point of going DIY TBI would be to save money. I just dropped close to $3000 in the engine, instead of buying another car. There is nothing left over, but thank goodness I have a job in the area. There seems to be a bigger support base for the TBI, and its more of my kind of thing. If the rebuild kit for my carb was the wrong one, I wouldn’t even know. The only help I would get would be from an inanimate object-the carb repair book :unsure:🙂 Since you need to do this yourself, you have two options for this, repair or replace the carb.
There is a book, called a HAYNES TECHBOOK on Rochester carb repair. Most book stores or parts houses can order this book for you or you can go the Haynes website and order it. It costs from 19.95 to 26.95, which varies according to where you find the book. that is the most complete book on the subject of Rochester carbs. It will show you a picture by picture guide to disassembly and calibrating, the difficult part, the carb. The hard part will be finding the parts to rebuild with, most kits do not include some of the wearable parts of the carb.Replacement may your easiest option, just buy a after market carb and go, and parts are easier to find for the aftermarket. Good Luck.
Brownbear, It’s really not that difficult to put a GM throttle body on there. go to a pull-a-part style salvage yard and get the wiring, computer, distributor, you know everything off a chevy truck. Then go buy a new fuel pump for that donor truck to use on your car. Get a wiring diagram for that truck also. I’ve done this a couple of times and for me the hardest part or the biggest pain was just installing the fuel pump in the tank and running return fuel lines. Whole mess probably won’t cost you 300 bucks and they work just fine. You will also have to install an O2 sensor into one of the exhaust pipes. Just do it man! You’ll learn a lot about GM’s simplest fuel injection. Good Luck. 🙂
Thats exactly what I intend to do :). There is no pick a part here 🙁 but I just bought a Tbi off of Ebay and a small fuel pump that im going to use inline with the mechanical one. Good thing I bought a new 1-wire alternator that goes directly to the battery. The old alternator connector can be a professional looking connection (not a soldered joint) that can go to the megasquirt ECU or fuel pump now 🙂 I’m glad I didn’t spend the effort on rebuilding the carb with no help-thats a skill I just don’t have. This megasquirt install is my kind of thing 🙂
I actually trouble-shot the carb down to the high idle cam not kicking down. I can mash on the gas pedal all I want and it won’t idle down. The electric choke works perfectly well. It stays closed and opens slowly when its warm. It doesn’t matter how far out the high idle screw is cause it won’t come off of that cam. I haven’t seen that problem anywhere else online, its all been coil this and that. Not being a mechanic i’m just done with it.
Your cheapest option but need a bit of work is to get a intake and above from first generation TBI as well as MAP and ECT sensor, the distributor, computer, and fuel pump. You can easily get all those for 300$ considering you need to spend the time to get at the fuel pump on the vehicle you can get part on.
Mega Squirt will only read data and require a decent amount of tuning. It doesn’t take the gas composition to do the math. You will spend time and frustration. It only read sensor and process them…
If you have not a mild modification stick a factory computer for now and then you can upgrade the ECM with a programmable one.
If the vehicle you are modifying is your project car…. you may want to budget and them upgrade to an multiport injection. More money but if you are planning to keep it do it right.
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