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78 nova 4 dr base model (going tbi)

2K views 6 replies 4 participants last post by  firstnova78 
#1 ·
Hi everyone wellmI'm a fairly new member I've been enjoying and learning from everyone else's threads. Well to the point I guess.
The car has a stock 305 carb which was ok till the cam went flat. Reason for wanting to go tbi is I haven't driven a carb in a while and have gotten used to just hopping in a car and taking off. With the carb I don't have the patience to wait for the car to warm up and could be why the cam went flat.
OK so on to the plan. I would have never been happy with the 305 anyway so would of came out either way.
I have little to no budget so I'm a big do it yourselfer plus my old lady still a little upset that I bought the car and the motor already went out. Ah what can you do.
Well I'm going with the 747 computer which I already have as well as the harness. Man that was a mess wires. Working on getting the engine. Gotta find a good running one hopefully. Can't do any rebuilding...my apts might not like that.
For the fuel pump I think I'm going to drop one in the tank but the ones that are spring loaded well the one that has the bucket since there's no baffle in the tank and I'd need a return line either way.
Help i will definitely need please is for the harness as well as figuring the wiring for the fuel pump business. Can I just wire up the new fuel pump to the old fuel pumps wiring or will I have to run something.
Well many thanks in advance and any tips and help is greatly appreciated.
 
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#4 ·
It had a mechanical fuel pump, no factory wires go back to thr tank to operate one, you'll have to run your own, probably using the fi harnes to trigger a fuel pump relay and then route that to whatever electric pump you decide to use.

The only wires back there on a factory nova is for the fuel level sender
 
#5 ·
See that's what I was thinking cuz Yea it's a mechanical pump. Well the good thing is I have the truck that I'm using for parts so no to big deal. Anyone know any good links or persons with experience on separating wires needed and not needed on the harness then how I wire the ecm.
Thanks for the comments and helps.
 
#6 ·
if your going to go through all the trouble of wiring up efi.... your going to need the complete diagram from your donor vehicle ( a chiltons or hayes manual will do it for ya for around 20 bucks...) also you need to drop the tank...completely flush it.. take it to a welder who will do gas tanks and have them weld in a bung for a return line. (unless you are a welder...) an old timer trick was to dump the tank... flush it with mineral spirits and then pull up another car hook a hose to the exhaust pipe and let it blow th exhaust into the tank...while you cut and weld (no oxygen-no flame) I WOULDNT RECOMMEND ITbut I have seen it done...

also you need the correct pick up for an in tank fuel pump..which will require some fabrication. OR you could slap an external pump on the rail with a pre and post filter... then an external regulator in the engine bay with a return line from that to the tank.

Fun hunh? ok... now once you have done the wiring and the fuel pump business remember the factory tbi computer needs to be flashed for your car/ engine combo. if your running anything other than a factory cam and heads... start looking for somebody to flash that bugger.

make sure you have bungs in the exhaust for an 02 sensor and 2 temp sensors for the computer to read. Also may have to find a way to install a crank and cam sensor for that ecu depending on the year its out of.

....all that for TBI... if I wanted to do all that... (which could cost around 2grand with prom flashing..fabrication and a decent fuel system upgrade...) it starts looking like one of those aftermarket FI set ups is pretty competitively priced...( depending on the unit 1800 - 3500 bucks)

If you still want to do all the fabbing and hair pulling i applaud you... but If your doing all that..go whole hog and and go tuned port... those modify better and have better throttle response and some aftermarket support ( larger runners and throttle bodies and manifolds...larger injectors etc..)

if budget is that much of an issue... drop in a nice rv cam in that 305 with a timing chain and gears. cost of cam and timing set plus gaskets and oil will set you back less than 400 bucks and unless your planning on hardcore racing..305 is great for the street ( all bottom end torque and its easier at the pump)

just my 2 cents bud. Happy wife = happy life!
 
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