//<86TA>\\

iTrader: (14)

i believe this is the right forum if not sorry.

was over at my buddys house tuesday and he just got a third gen. its an 85 T/A with a swapped 350, 700r4 with a edelbrock carb which is a 600cfm. the car has seen better days but is not that bad, but has a drivability problem. under normal conditions it runs and drives great but, if you floor it from a stop it stumbles bad and will sometimes stall! and even at highway speeds, if you floor it, the engine seems to die for a second, then goes like hell. i figured it had something to do with the carb so i grabbed some spair parts i had at home and was helping him, i changed the tuning all over the place as well as the timing and advance but didnt really get any change. so for ***** and giggles i removed the linkage for the secondaries and well hot damn it worked fine! absolutly no hesitation at all stopped or at speed. so i changed the secondairy jets out for a smaller size and didnt see any changes from the original problems when i hooked the secondaries back up. took it apart again and put the smallest jets edelbrock makes in the thing and still no change. so this is getting a little confusing and i was wondering if anyone else here has a similar problem and an idea how to fix it. i dont think its the ignition but thats another avenue, but it would seem to me that if it was the problem would always be around and not just when the secondaries are connected

thanks

SPIKE

iTrader: (1)

just for the heck of it did you try to move the pump shot to the closest hole for more pump shot ?

Tobias05

what size accelerator nozzles and what stiffness metering springs do you have in there?

88 Z28 Guy

iTrader: (1)

Im having the same problem so when you get it straightned out please let me know what you did.

//<86TA>\\

iTrader: (14)

yeah i moved the accelerator pump to all positions trying to iron things out, it runs better at a higher setting than a lower one but still we have the same results, it still has the stock accelerator pump, so maybe it needs a bigger one?. the step-up springs are silver, the heaviest ones, and right now it has a 1427(stock size) main jet with a 1455? rod and the secondaries are 1420 jets. i was going to tinker with it tuesday night, so maybe i can get some more ideas between now and then

five7kid

iTrader: (14)

Why did you go with smaller secondary jets? That's a lean problem, and you're making it leaner. (Unless you meant smaller rods.)

I'll have to admit I haven't worked with those Performer carbs, but nothing I've heard about them impresses me. Putting one on in place of a stock 3rd gen carb is one of the most common downgrades we hear about here, and I just don't understand why people do it.

Out of curiosity, what distributor does this car have on it?

//<86TA>\\

iTrader: (14)

its a summit blueprinted hei, or supposed to be, i made the secondaries rich and then leaned then out trying to figure out wtf was going on.

i am starting to get the idea that these preformer carbs are crap, they are suck a pain in the *** to deal with and make work i dont think its worth it. time to go holley i think

//<86TA>\\

iTrader: (14)

well retuned the 600 and could not prove anything with it, so i swapped it out for a 750. now it runs like a mexican for the border, once it gets rolling, but still has a problem from a stop or a slow start, if you floor it, the car does nothing, pretty much just turns off and thats it. assuming that it somehow leaned out? upon the 750 swap i recalibrated the 750 richer and it got better, but didnt go away, you cant tune the damn thing any richer, wtf is going on here?

//<86TA>\\

iTrader: (14)

hey its been a while, but i think i figured out this damn carb so you guys who are/were intrested here it goes.

I traced the problem i was having to the secondaries, upon WOT the car would die out and cough and whatnot, and overall not respond the way i wanted, after it got over its quick sputter, it took off like a bat out of hell. so i was fiddleing with it trying to get a better understanding of the secondaries and i came upon this solution, we at least it worked for me. the problem was that the air valve that sits over the secondary venturies, does not block the throttle bore enough to retain suction at the initial opening of the secondaries, so what i did was remove them and flatten out the rear portion so that when they are wide open the to of the air valve blade is perfectly vertical, instead of a bit forward as i came from the factory. with this adjustment made, the air valve closes off more of the throttle bore around the secondary boosters and holds in more vaccum when the throttle is rapidly opened.

i hope this helps some of you.

i dont have any pics but if you really need them i can get you some.

J dorris

I need some pics