I just installed a older redone 1977 400, it runs and sounds great, Its just that past half throttle in any gear it starts to choke and not want to run. I redid the timing to 6degrees btdc and it got a little better but i still don't have any top-end.

 

Is it carb or fuel injected? If it's a carb, when was the last time it was tuned. Also, try hooking a vacuum gauge up to see what kind of readings you get.

 

what exhaust are you using as well? i had a 72 509 casting a few yrs back and with a tuned 650 carb it ran great up to 5,500. no need to go higher imo.

 

its a carb,no sur when it was lat tuned, and its also only has headmanlongtubeheaders with no real exhaust yet. The strange thing is if i slowly acel i can get a few hundred more rpm's out of it opposed to stepping on it right away where it will reach 2000 or so and dosent want to run at all. And it has normal vacume pressure.....if i take off the vacume advance tube,do you think it will help at all?

 

Does the engine pop or bang at 2500 or just stops accelerating? Check fuel pressure/volume

 

Try just accelerating normally without a lot gas pedal. Shift manually if you have too. See if the car keeps going at half throttle. This is sounding like it might be an accelerator pump in the carb. Try to pinpoint the rpm she falls on her face. Also, are you using the 700r4 trans with a tv cable. It could be out of adjustment, which will cause the trans not to shift right. Sorry if you posted the trans and I didn't see it

 

its a t-5 trans, but its more of that feeling when you step on the gas a you feel the 4brl kick in, its that its not kicking in. It seemes like thers extra gas in the exahaust also when it happens and you can smell the unburnt fuel as soon as it happens.....its feels like if you were driving a riding lawnmower and somone ran up a flicked you choke on, it would still run but it dosent want to..,.untill you release the gas pedal and all is back to normal.

 

Your choke aint stickin is it? So your engine doesnt like the 4bl, what kinda carb? May just need to rejet or change metering rods.

 

It's a edelbrock 650???..an older one, the engine ran for years before i installed it, and it was always fine in the high rpm's in the low geared truck it was in. I just dont know what changed form then to now. And my choke isnt sticking it works how it should. I alos put my carb on the murcury meter and it said all 4brls seemd fine in the low range rpm's....

 

are you currently running a fuel pressure regulator? what are you useing for a fuelpump?

 

And it dosent pop or bang it just runs fine, and feels like some one fliped on my choke when the 4brls supposed to kick in

 

its a stock fuel pump, the one right on the front left of the block. I also have a clear inline fuel filter, i know the fuels getting ther it just seems like ther might be too much fuel by how the car smells/smokes when it stops acelerating.

 

Im sure your carb flows fine, but you said you smell fuel and the car slows down, so your running really rich when the secondaries open or you are losing spark power. My experience with the edelbrocks is that they can be very picky.

 

i dont think its spark im losin, ill hear it fire everynow and then when its happening. I think that it is dumping too much gas in. And this edelbrock is soo complex i want to get a holley, but thats gonna cost money...so what should i do on adjustiing/fixing it?

 

do you still have the in-tank fuelpump hooked up too? just trying to cover all the bases. is this the same carb you had on there when the motor ran fine? maybe its time for a carb rebuild?

 

if there is an intank fuelpump stock, then i still have one. I thought that was the only one on the block. and its the same carb on the motor as it had 4days previous when it ran fine in the truck it was in.

 

ok sounds like my same issue i had, pull your fuel line off the carb and check your fuel flow. On another note if your car was fuel injection before and you still have stock fuel pump it, then the fuel pump could be overpowering the carb (not likely) but i have seen it.

 

id like to hear a little more info about the car. what year? as Speedy asked, was it fuel injected? what distributer are you useing? the more info the better. im a holley fan, but eddy carbs arent that bad. im thinking you got too much fuel pressure if it was fuel injected and the in-tank pump is still hooked up.

 

Does the carb have vacuum or mechanical secondaries?

 

mechanical secondarys, and how mch fuel pressure should i be expecting? Its a MSD autozone special for like 30$ on the ingnition. And it never was fuel injected before. This carbs been on the engine for most of its life along with the fuel pump im running. If ther is an in tank fuel pump it worked fine with my smaller 305 and smaller roch carb

 

I would look for at least 6 psi fuel pressure. Just for giggles I'd like you to try something. Get some carb cleaner and spray it around the base of the carb, intake, and vacuum lines. What you're looking for is an idle that quickly levels out and then bogs down a bit. Also, are you sure the mechanical secondaries are not opening? That would imply that either the throttle cable isn't pulling the linkage back enough to open them, the linkage was messed up during the swap, or that a screw or some other obstacle is obstructing the linkage's ability to open the secondaries correctly.

 

found the problem, the secondarys arnt not opening, they are stuck all the way open and the linkage wont move them. Im gonna take it off and take the butterflys out to see if i can free it up

 

Thats good. Might as well do a rebuild on it too.

 

yep, that looks like the plan for now

 

So the linkage was the problem after all. Glad you're gonna get it fixed

 

got all 4brls opening, but it still isnt working too great. I did just over a 9mile trip today and only used all 4brls once and i burned roughly 4.25gals of gas. It didnt seem to be running too rich at lower speeds where you can really smell the exhaust. and the carb kicked in nicely, i was able to spin my big 275 good years in second gear instead of just chirping them. I just dont understand why the mpg's dropped form 15 to 16 in the truck to like 2....is it the lack of pressure form no exhaust or what. When i fixed the carb linkage i didnt touch anything else except the two butterflys.

 

Pull your spark plugs out and tell us what color they are, black, tan or white.

 

Are the motor's the same size and cam? It sounds like either you're running rich or maybe the o2 sensor says you're running lean, so the mixture is getting fattened up...a lot.

 

The plugs started off white on the very tips and are half white and half black, and wher is the o2 sensor located?


P.s...how do you post pics to your profile?

 

The o2 sensor is in your exhaust pipe. I'm guessing left side. The white means you're running too hot, but the black is oil deposits possibly.

 

since you deleted the computer you have no o2 sensor..... your running the same carb i had on mine yrs ago and im trying to remember why i had this issue in the first few weeks? what size air filter are you running? the problem should be on the car side of things tho considering it ran fine a few days before in another vehicle. you running a cat converter? look for all the differences and try to use the process of elimination. did you remove the dizzy to install the motor? is the timing dead on?

 

Okay, if he's not running a computer anymore, then we're back to ignition timing and fuel delivery. The white plug suggests he's running hot, which is probably too much ignition timing or he needs a colder plug.

 

well there is no exhaust past the headers and no computer, my air filter is a k&n like 12in diamater and its running at 197degrees on a like 2min idelig, even colder when driving

 

and the timing is right on, the car runs great and i would be completly satisifyed with it except for the gas drinking/ running rich problem. I wouldnt even think theres anything wrong with the motor for the amount of power it has, maybe its just stronger than my 305 but still not runnig at full potential and i dont know what to expect. but you can smell the gas in the exhaustseverly, im going to check all 8 are fireing, but i think i would of noticed that.

 

Hey for fun start the car and let it idle, check the header tube temps near the heads if you can.

 

its outa range of my electric thermometer...i think it maxes out at around 500

 

Maybe youre running to lean.

 

Maybe we need to start over with a little more information. You said the 400 was redone. The carb is a 650 edelbrock unit with mechanical secondaries that were sticking due to a linkage issue. How long ago was the 400 redone? And after it was rebuilt, did it run in another vehicle?

The plug being to hot, you really need to switch to a colder plug. The temp range of the spark plug has nothing to do with the temp of the vehicle coolant. That plug is white, which means it either is 1 range too hot, or the ignition timing is wrong. Nothing else will cause that. If you're 100% sure the timing is right, then you need to switch to a colder running plug. The fuel smell means that we have unburnt fuel in the system. Have you checked and adjusted the idle speed and mixture screws accordingly. Also, a vacuum test might shed some light on what's going on inside the motor. If you don't have one, then rent one from the local auto parts store. As a side benefit, you can use the vacuum tester to help you dial the carb in. We can get this fixed, but we need more information than we currently have to begin the diagnostic process again.

 

Your smell, is it raw fuel or like a bad fuel/bad exhaust smell?

 

Is this fixed?

 

ok, i took off the 4brl on there and put on the smaller one from my stock 305. It ran identicle to the carb that was on there except i got a more reasonable 15mpg...which leads me to think rebuild or not its time for a carb upgrade. I think that the back two barrels were drooling gas constantly or not closing all the way. And i set my timing to 6btdc, the book said 4 btdc but the car sounded rough ideling at 4. And i talked to some others at the local parts store and they said that a 400 usually runns around 12 to 13 btdc WHATS the right one!??

 

Advance your timing and see how it runs...

 

8 to 12-13 btdc literally feels the same and sounds the same. Its just that if the wrong timing can make it run hot i want to pinpoint the right setting. I know its not the 6 btdc i had it at, because the vacuum advance helped alot more in that 8 to 13 range.

 

run 11 btdc and see how it likes that

 

ok ill try it