Now if i want to do the carb swap i got all the nessasary parts needed, now could i use the stock coil and distributer with the carb and intake would it work since the spark runs off the computer and so did the tbi and since no fuel will come out of the injectors and i have fuel pressure. my other question is how much psi should i run for the carb? i know tbi runs like 10psi what doe sthe carb? well anyway i put alot of thought into this and i think it should work. but i do have the hei and the distributer im just not sure on how to run the hei cuz of the pugs on the cap dont know thats y i want to run the tbi distributer.

 

In order for the spark to be accurate with the fuel you have to switch with the older style vacuum advance distributor.

 

thats the thing i dont understand the spark works it goes around the distributer right so what is the difference? if it computer controled spark im gonna try it and let u know what happens.

 

I think it was actually RBob that ran a 7747 for timing control on a carbed engine, then ended up switching to TBI.

 

Yep RBob did it and wrote a paper on it on the diy-efi not sure if you can still find it there. Pablo also ran his motor like that for a while, I'd think you'd have better control over timing going the ECM route, but I'm not sure what measures have to be taken to avoid throwing codes.

 

I forgot a key factor in timing which would make sense that you can run it with a carb. Nevermind, try it out let us know how it works out.

 

well i need to know if it will run with what im gona do if it does ill post the results if not ill have to switch it to hei.

 

I'm not going to be of any help on this perticular thread, but I've just gotta ask.

what benefit could there possibly be from going to carb and keeping the ecm?

many people switch to carb to remove the ecm.

82-84 cars have carb with ecm, but it's generally understood that they aren't really as efficient as tbi or tpi when it comes to gas mileage, optimum tuning, so on.

so, where's the upside? what's the point?

I suppose you might more easily be able to get more cfm's out of because well, they make massive carbs, but even that is to some extent pointless, you'll never need over 800cfm, even if you're making 400hp, and at any point before then you're going to have a hell of a time tuning an 800cfm carb ideally for whatever you're motor's set at.

I dunno, I'm not trying to start an argument, I'm just wondering where your motivation is for making something that from where I can see is fairly pointless, even harder?

I gues my two questions are, 1: why not just go full vacuum and just rid yourself of the ecm altogether if you're going carb

and 2: why are you going carb in the first place?

p.s. assume that everything I just stated is my "understanding" of how this works, not fact, so people please don't go around saying I'm spreading misinformation, just correct me and move on, I'm just trying to figure out why people do this.

 

ok for one the tbi i have wont support 370hp and if it did i would not get as much power out of it. 2 i can see where ur coming from with that i am going to switch it to hei here tonight. then it all should be running up to specs but there is one small problem when it runs it leaks oil from the back of the engine on the driverside head i think there might be a port hole i forgot to plug or something cuz i know its not the sending unit so what else could it be.

 

If your using the ECM, your still going to need to burn chips to set the timing table up right. The car will just run the same as it did before with the stock timing. The solution is to either get a burner or get a non-CC HEI dist.

If you have the burner, you can put a vac. advance style timing curve in to the SA table if you dont want to mess around with it alot. I did in mine, and it works fairly well.

 

well i had it run and it does iam going to put the hei vacume advanced on it so it runs better but thanks.

 

Dimented is right, I think it's a matter of expenses. If you already have a distributor to use then use that by all means. I think people go the ECM controlled route mainly because then they won't have to shell out the extra cash for a new distributor because they can use all the stock ignition components.

 

CRAP! Sorry Freeloader. I hit the edit button by mistake!

 

My bad... I didnt mean to plow over your post like that.