Trans_AM_88

hey guys, i have a edelbrock carb (1405) and my car hesitates when i start getting near WOT and i lose pretty much all power when i hit full throttle. also, my car seems to stall when i take corners going a little fast. what do you guys think it could be?

pheonix305

it sounds like your running rich in the power mode of the carb. if you have the owners manuel you should read it throught and it will explain how to tune it and describe symptoms. hope this helps.

firbird

Could be allot of things what is your set up? What is your timing at? Every thing else in good mechanical condition such as plugs, wires, cap and rotor? When you say it starts to hesitate getting near wot and loses pretty much all power when you hit wot what rpm will it do it at or is just any? Check your plugs or if you can look back and tell quit obvious that you are running rich lean it out some but more than likely you are hitting a lean spot or spots. The plugs can tell you a lot.

When you hit a hard turn and the car wants to stall as far as my experience I have not encountered an edel that did not have that problem, but first you still want to find out if your floats are hanged right. Mine got to a point were I called up edelbrock and they said you could do a few things to stop this from happening. The first thing they said when you take the upper portion off you will see a channel were gas can go from one bowl to another and he said to block this and I did but I did not notice any improvements from this. The second thing he told me was that if that did not fix it an off road needle and seat will fix this problem. A week later I got a Holley and sold the eldel. Never got to do that to the other carb so I don t know what the negative effects are from doing this if any?

Trans_AM_88

thanks for the replies.

edels website had an explination for my problems: the floats. yeah, it looks like i was running pretty rich, my floats were close to the top of the carb. i readjusted them to 7/16's (as per edel) and the car seems to start a lot better now and i havent experienced stalling around corners yet either. BUT i still have problems at WOT. and to be honest, it really feels as if my entire power range is being restricted somehow...im sorry i cannot explain it exactly, but all the power just isnt there. anyway, i'll give the spark plugs a look to see what going on with them.

i have a new rotor, cap, wires, and pickup. and the spark plugs were changed about 6 months ago, they are the bosch 2 prong platinums ( i know ). would some AC Delcos be better than the platinums?

also, here is my setup:

9 inch cheapo air cleaner
edelbrock 1405 600cfm 4 barrel carb with electric choke installed
edelbrock performer intake
L98 engine (350 ci)

according to edelbrocks calculations, my engine maxes out at about 550 cfm, so the carb should be big enough right?

firbird

Oh yea that’s more than good enough for your set up, 600 is plenty. Your set up is not that bad the Bosch plugs I could do without and I chose normal ac Delco over them but that’s shouldn’t be your problem in less completely fould out. Again what is your timing at, base...? Overall..? Very important to know. Is the carb stock and unchanged from when it came from the factory?

Trans_AM_88

the best i can recall, the timing is at about 8-12 degrees retarded...

for the carb, i added an electric choke since i didnt have any of the manual choke hardware. as i stated before i recently adjusted the floats to the proper settings. but i got this carb used, so unfortunatly i cant be certain that it hasnt been tampered with. but there should be a way to set it back to factory settings, correct?

Bandit5

I only know a little bit of Holley tuning. For mine, I would turn the air and fuel idle screws all the way in, then back them out 1.25 turns, and start from there.

But you need to describe your bog better. When you hit it, does it just fall flat on it's face? Does it have little spurts of energy that die off quickly?

It could be either rich or lean. Since you have already set the float, you should invest in a carb tuner (rich/lean indicator) and turn the mixture screws until you get it to "stoich" which would be indicating both rich and lean conditions.

firbird

Well I brought up that idea because it might have been tuned for something a little more radical then what you have and when placed on your car will not run like it should. Many things the previous owner might have changed, rods, springs, jets, or changed something else about it. Trans am 88 mentions it’s threw his complete power band not just short spurts or flat spots and that its there just does not feel like its all there.

Did you mean advanced? I hope so. I don’t know exactly what a carbed l98 wants in timing but I would imagine start any were from 6-10 btc in timing (advanced) with something like 38 overall (advanced) and again I am not sure exactly what your engine needs if anyone else has better please tell.

Trans_AM_88

yes, sorry i meant advanced...i've got to stop posting when it's late

what's the difference between timing and overall timing? i have a timing light, and that shows the line being at somewheres around 10* BTC.

i found these on the edelbrock website:

Accelerator Pump Assembly....#1469
Carburetor Rebuild Kit (includes parts & gaskets to rebuild Edelbrock square-bore carbs) ....#1477
Replacement Needles and Seats (.0935" diameter, pair) ....#1498

what do you think? also, do you think i should buy an air/fuel ratio guage?

Trans_AM_88

guys...im still having all my original problems...my car sputters around corners (almost stalls out) and the power just isnt all there. i dont know what to do here, im thinking of getting a new carb..

Trans_AM_88

anyone...im stumped here

Bandit5

If you are having so much trouble, I think it would just be easier if you bought a Holley 600 vac sec. Bolt it on and go.

Trans_AM_88

right, i agree...but the thing is i got a clutch (barely used) pressure plate, vac. advance distributor, and the carb for $250. for a poor guy like me, i had to take it .

no doubt, i'd love to get a holley. i got 2 buddies who run/ran edels and they have similar problems. not as extreme as me, but still there. is getting a new carb really my only choice?

Trans_AM_88

i looked at some holley carbs...i narrowed it down to 2: what do you guys think? any other suggestions?


Holley 600 CFM Vacuum Secondary Carb ($240):
http://www.holley.com/HiOctn/ProdLin...C/0-1850C.html

Holley 670 CFM Street Avenger Carburetor ($370):
http://www.holley.com/HiOctn/ProdLin...C/0-80670.html


they are both vaccum secondaries with electric choke. will the 670 cfm give me a lot more power? is the street avenger carb worth the $130 more?

Bandit5

If you are making 300HP or more than I would use the 670, otherwise go with the 600. If you over carb it, it will run like crap and not give you the off idle power you need. It is better to under carb, since you get MUCH better streetability, the responce will be much better.

The street avenger is nice, it allows for easy adjustments for the secondaries and the float level, very nice features if you know a lot about carb tuning. But, if you are not the carb expert, you are gonna have neat features that you'll never use.

A new carb is not your only option, but it is the easiest, and ultimately the best if you prefer Holley.

Trans_AM_88

should i get mechanical or vaccum secondaries? theres a 600cfm double pumper mech. sec. for $250 on jegs. i like the sound of "instant response" with mech. secondaries

Bandit5

With a T-5, it shouldn't be a problem. But if you had an automatic, I would advise against it unless it was a 3,000 or higher stall.

That will do you fine, less to adjust. But... double pumpers will give you absolute **** for gas mileage. If you want it to be more streetable, go with the vacuum sec.

Trans_AM_88

well my old setup got like 5-8 mpg, can it get much worse than that?

Bandit5

Sounds like you had serious tuning problems... it shouldn't get worse than that, assuming it is tuned right.

Trans_AM_88

well i ordered a 600 cfm Holley mechanical secondary double pumper. we'll see if that helps

xeroxed

i think you did the right thing. i had an edelbrock once and it was the biggest piece of crap. then i switched to holley and havent even considered another carb. i bet the edelbrocks problem is the mixture screws are broken which is what i found wrong with the edelbrock i had no matter where you turned them they did nothing.

Trans_AM_88

LOL, thats what happened to me. its like they were either on or off.sometimes you just gotta start over with new stuff so you know that everything is ok. it just gives me some piece of mind.

Trans_AM_88

i got the new carburetor, put it in, STILL THE SAME EXACT PROBLEMS!!!! WTF?

it helped a bit with new spark plugs...but something just isnt right...

from my other thread (https://www.thirdgen.org/techbb2/sho...postid=1696624) on the general engine tech:

xeroxed

are you using the stock tpi fuel pump or did you go with a mechanical pump or an aftermarket electric pump? if you went mechanical or aftermarket electric did you remove the tpi pump from the tank and use a carbed sending unit? if your still using the stock tpi pump it might not be able to supply as much gas as you need. if you didnt take the pump out its like trying to suck water threw a straw compared to a 1 inch pipe. those pumps cause a lot of fuel starvation if your not using them and trying to suck threw them.

Trans_AM_88

yeah, im guilty. i left the stock pump where it is and the old fuel filter. is the pump inside or on top of the tank??


also im gettin 7psi at the carb, isnt that sufficient?

xeroxed

if your still using the stock pump do you have the gauge inside your car so you can see if your getting a consistant 7 psi to the carb while driving? if your still using the stock pump do you have a regulater on it and if you do you might need to play with it a bit to get sufficient fuel. but if your just using a mechanical pump youll need to drop the gas tank and cut the pump piece off and put a 3/8 rubber hose on the end of the line or use a carbed car sending unit. i cant believe i totally forgot this and didnt think of it before suggesting a new carb.

Trans_AM_88

no i have an aftermarket electric pump. the FP gauge is on the carb so i can see it while im driving. either way, youre suggesting i have not enough fuel going in the engine? then how come my plugs are black

Trans_AM_88

alright i tried an alternate route...i put on a 45,000 volt accel coil. it did absolutely NOTHING. maybe it is fuel starvation.

im going to do a test: take a line directly from the fuel pump and put it in a jug of gasoline. jug > fuel filter > pump > AFPR > carb. that the best way to figure out if something before the fuel filter is clogging my lines.

Trans_AM_88

it cant be fuel starvation...im still running rich. do you guys think i need new jets?

Holley Mechanical Secondary Double Pumper Carb (600cfm / Manual Choke)

Primary Main Jet: .070"
Secondary Main Jet: .076"
Single-Stage Power Valve: Opening Vacuum: 6.5'' Hg.
Primary Discharge Nozzle Size: .025"

Trans_AM_88

well it turns out JEGS sent me a 750 holley, not a 600 like i had ordered. what a bunch of pain and hassle that caused me. but i got it for $250, and it retails for like $570

maybe i can turn this to work on my L98

Air_Adam

750 is a good size for a healthy 350, stick with that.