itmedylan

im driving a 91 rs 305 with a carb swap, i just bought the car it looks amazing but its not running as good as it should be. it stumbles at take off and has no power when i gun it at high rpms. it has a 1406 carb on it with a performer intake and flows 80 series. those are the only aftermarket parts that i notice. is there something i need to do? how should the carb be tuned and what should my timing be set at? it has all the wires under the hood for the tbi still i dont plan on going back anytime soon should i pull them out ? if so witch ones? and my car smells like it runs really rich.... i need more power!!! plz help.

Grampa

No info as to whether the distributor was changed along with manifold and carb.
You may wish to check out Edelbrocks tuning/questions section to give you some pointers on it, specifically.
Also, are you sure the electric choke is working properly?
If it's sticking some, you would have crappy performance, no high end, because the blade is stuck closed.
It could also answer why it smells so rich.
Is there a good fuel filter in there somewhere?
Also, is there a fuel pressure regulator, and what pressure are you getting to the carb?

Stock Car Racer

My advice is to get rid of everything and either move up to a MSD ignition system or a modified HEI distributor.
Get rid of the wiring harness and the computer and all the smog stuff and get rid of the sensors and the exhaust manifolds and maybe even get rid of the 305.

There is a difference between model years and the ones that I liked were the 1984 - 85 G motor which came with a aluminum four barrel intake manifold stock from the factory.

The later models used a one piece rear main seal and different flywheel and bolt pattern on the crank shaft and was a real piece of garbage.

A even better situation would be to put in a 350 or a 400 SBC!

five7kid

iTrader: (14)

All U.S.-delivered 3rd gen V8's with carbs had an aluminum four barrel intake manifold stock from the factory. In fact, it was the same part whether it was the "G" L69 or "H" LG4.

itmedylan

No info as to whether the distributor was changed along with manifold and carb.
You may wish to check out Edelbrocks tuning/questions section to give you some pointers on it, specifically.
Also, are you sure the electric choke is working properly?


on the distributor im not sure if it had been changed out.. the electric choke is hooked up properly i cleaned the electric choke and checked it and it seemed to open after it warmed up. i was reading something about advancing timing up to 6 degrees ? does that sound right? im thinking maybe a new carb? this one is a little old. is a 600cfm an okay size on a 305? i want to have moderate gas but i also want to be able to have some fun. i removed the smog hoses and things i never took off the pump though will that make any differnce in performance if i pull it off? i dont see a fuel regulator it has an external fuel pump though that sits under the hood, im not sure how much fuel its putting out.although occastionally i see some fuel leaking from the fittings on the pump, maybe too much pressure?

ericg83z28

not true my 1983 Z28 came with an aluminum rochester and a cast iron intake manifold

itmedylan

how can i see if distributor has been changed out?

five7kid

iTrader: (14)

Canadian?

RedneckNo4

are there more than 2 wires going to it, or a vacuum hose, is it big or does it have a dist wire going to a coil? a picture of the distributor from the drivers side would help

is the pump an electric fuel pump or is it on the engine block? is sounds like the pressure may be too high

a 600cfm carb will work

itmedylan

it has more than 2 wires going too it, i do not see an external coil. the fuel pump is under the hood it isnt on the block it is a fuel pump that you can buy at autozone, i do not see a fuel pressure regulator or anything going to it.

ericg83z28

i am in canada , but the car was made in ohio , im not sure if it matters tho

F_BODYKING NC

hay man just let you know i have any 88 that i pulled all tha tbi out and put a 350 cammed motor in and i put my first fuel pump under tha hood and with in 3 to 4 weeks it started to give me a hard time and then died. then i found out that there are better at pushing fuel than pulling it and you should get a regulater most cards run low presser mine only runs on 6 psi need any help hit me up i have been there do not take tha cpu out it runs you vats system and tha car mite not run with out it unless you find out a way to put power to tha fuel spark and starter i know a real easy way to buy pass the system if you want to but you have to keep tha cpu or going to have to do it tha hard way i have 6 3rd gens and 2 4th gens 1 camaro and 1 trans am so i have been in and out o them more than i can count hit me up

itmedylan

okay, im going to throw a regulator on it should i put the regulator go between the pump and the tank or between the pump and carb?

Grampa

You should put the regulator under the hood, along with a pressure gauge. This way, you can adjust it, and see where the pressure is, without having to have another person with you or, having to go back and forth from under rear of car back to front to read gauge, back to rear to adjust...

I agree with the pushing aspect of fuel pumps. Most are better utilized that way. Make sure to place a fuel filter at pump. I'd place one before it hits the pump. Some guys put them on both sides of the pump, but, I don't see the point of that, personally. Each to their own. Put at least one in there though. Protect your equipment and investment!

Depending upon how good you are at wiring, I'd run the wiring for the pump inside the car, dropping it outside very near to where you place the fuel pump. This removes chances of insulation rub through causing shorts, and shutting you down, or worse, a fire! Always use grommets when you go through bulkheads, and use clamps, or wire chase tubing as a mechanical barrier against chaffing.
Best to use a relay to control the power to the pump.
It makes for a little bit more wire, but it's MUCH safer and much easier to deal with, in the event something goes wrong. Fused at the power buss, relayed with 12ga.(minimum, preferably 10 ga.) wire from there to the pump.

A friend of mine, many years ago, ran a POS setup up for his electric fp, and a few hours later, he had severe burns to his legs, arms and hands, and, had no car.
Seems the shitty wiring he'd done, rubbed raw on the chassis next to the fuel line, burned through while he was driving the car. (He didn't include a fuse feeding the circuit, the dumbass!)

Any time your'e dealing with fuels and electricity, be damned sure of what you're doing.

Refer to a wiring diagram. They're pretty simple, really.

And to think, he asked about what might be causing his problem with little or no power!!!

Sparkytfl

Theres two types of hei. Computer controlled and vacuum. Look at the metal base of it. Both types have a multi wire connector going from the metal base to the bump on the side of the cap. Both types also have a power wire and a tach wire going from the wiring harness to the bump on the cap. But if theres also another wire or set of wires coming from the base http://www.chevythunder.com/lg_HEI_2.jpg (I think later cars are different from the 4 wire plug shown here), and there isnt a vacuum canister on the front http://www.msdignition.com/uploadedI.../8365_full.jpg then theres a problem. It means that whatever idiot put that carb on never changed from the stock distributor.

The stock computer controlled distributor will never work right without the computer contrilling it properly, and the computer will never be able to control it properly because it no longer has all the sensors that were built into the fuel injection system. Just go up on ebay or into a junkyard and find a vacuum advance distributor, change its cap and rotor if necessary, and install that.

F_BODYKING NC

granpa's right: put both the regulator and the gage under the hood, make sure that the regulator is before the gage and after that see if you have power before taking the whole car apart...

DoubleV

Yikes!

itmedylan

well i put a regulator on it and i couldnt get any fuel to go through it so i took it back off. it still runs rich but i tuned carb a little better and it helped, i mainly smell fuel when i get into high rpms, what should my timing be advanced at? i messed with timimg a little bit, before i adjusted timing my friends 00 grand prix beat me by about 2 cars, after a little timing adjusting and carb tuning it was a very close race i won he won i won again. i was wondering exactly how far advanced i could time it running on 87 octane? and how exactly do i time it i did timing from an idle and spun disributor counter clock wise until it ran a little smoother, i have a timing gun now, it has an adustment **** on it for degrees what should i set it at and where should my marks line up when i do it? am i doing it at idle or from 3000rpms? and why am im running rich in high rpms?

killerz86

Try upgrading your ignition. Have you changed your spark plugs and wires? If your plugs dont burn the fuel completly your missing out on alot of power. also a hotter coil would help and should be a big permormance boost.

itmedylan

well i changed the plug wires to procomp wires, i guess msd knock offs. and i pulled a few plugs out and noticed i should probably go with hotter plugs, whats a reasonably cheap distributor. whats easiest way to change passenger side plugs? from bottom?

killerz86

You may not need to change the distribitor just the coil would be enough for now. Accel makes a good coil and was always the first part i changed when i would get a new F body. And with a lil effort all the plugs can be changed from the top. I once had a 85 with to much cam and it would foul plugs all thie time. actually even changed them on the side of the road a few times.

Doom86

I have an original 305 out of 83 camaro and it for sure has a aluminum intake.

itmedylan

and what should my timing be set at ? im running performer intake and 1406 carb.

itmedylan

should my distributor have an external coil?

Sparkytfl

No external coil. You need a vacuum advance HEI distributor with that carb or it will NEVER WORK RIGHT.

five7kid

iTrader: (14)

What mattered was where the car was originally delivered. LG4 cars delivered to Canada had the cast iron intake manifold.

For what that's worth to this thread...

itmedylan

well the distributor on it now has vaccuum advance so i figure its the right distributor although i should probably get hotter plugs and a new cap if not rotor too.can i put a hotter coil in the distributor i have now?

killerz86

Yeah You can still install a coil. Try that and then go smoke that 00 grand prix. You still need to get your fuel pressure figured out. I went from a TPI set up to a carbed 383 and the fuel was the worst part of the swap.

Sparkytfl

I dont remember there being any posts that confirmed that it was a vacuum advance.

naf

iTrader: (7)

1) Don't bother changing any heat ranges until you have the timing set correctly. Reading your plugs is useless when the timing is screwed.

2) Try timing it for 36 degrees total advance (all in). See how it runs and whether it pings. Adjust forward until it pings in small increments, then back off to the prior 'good' setting. This will get you in the ball park. Adjusting the weights for best advance curve is a little beyond a two minute post here, but there's tons of more detailed help here for that.

3) There's no need for a hotter coil until you begin to experience ignition problems. A hotter coil doesn't provide a hotter spark. It provides more ignition power when it's needed to jump a bigger gap, spark a more compressed mixture, etc. The spark plug will ONLY use the energy it needs, at that moment, to jump the gap.

4) You won't experience any ignition problems requiring more spark energy with properly functioning stock equipment on a stock motor with stock internals.

5) Run it for a while with the timing adjusted where you think it's right, then you can read your plugs for heat range and proper timing.

6) You should verify that the stock in-tank pump is still working. It should be enough to feed your motor once it's outfitted with the proper return style regulator (to drop its pressure). Trying to pull through a dead in-tank pump with an auxiliary pump is an exercise in 'waiting-for-the-auxiliary-pump-to-die'. The wait won't be long.

itmedylan

what am i turning "all in" ? how do i calculate total timing? right now the marking on the balancer is slighly less than an inch to the out side right (driverside) of the timing refernce markings.

itmedylan

my timing gun has adjustments on it can i set the **** at 36 and then just time my markings to 0* ?

Sparkytfl

Yes thats how you do it. (RE: the dialback timing light)

"All in" means unhook the vac advance (plug the line temporarily so you dont have a vac leak), then start increasing your rpms while watching with your timing light. You'll see your advance increase, and somewhere around 3000ish ideally, you'll see that your timing stops advancing with the increased engine speed. Thats the point where your springs are stretched out and your weights are pulled all the way out. If that "all in" rpm is a lot higher or lower than 3000, it would be good to buy a spring kit to adjust it.

Oh then theres the whole adjusting your vac advance thing. The basics of that are that the cans that come with different distributors have different amounts of advance. Once you set your mechanical timing, hook up your advance can, and check to make sure it doesnt increase your timing by more than 15 or 20. I had one once that went to like 27 and even though my mechanical timing was good, the engine pinged like crazy until I modded the can.

itmedylan

okay so i set my timing at 5* advanced any more than that it seems to idle way too high and sounds ruff, and anything below 0* it runs ruff and idles too low. im still not getting the power i need in my high rpm's.