i recenty took my car out of storage after being put away for a little over a year. it ran fine for a few weeks but recently started bogging down when i step on the gas. if i press it lightly and hold it, it sounds like absolute garbage and will jerk forward hard if i give it a little more (and then it runs like a champ at this point). ive done alot of work to my car though, its an 89 trans am GTA with a 5.7liter. its got a proform HEI distributor(coil in cap) with an adjustable vacuume advance, a 600cfm edelbrock carb, performer intake, and flowtech headers. ive tryed rebuilding the carb, adjusting the vacuume advance, idle mixture and accelerator pump settings, and i even replaced the coil wich looked suspiciously melted/chared and nothing helped at all. i dont know what is causeing this annoying flat spot, but its really getting on my nerves because everything includeing the engine is practicaly brand new and it never did this before.

 

I know this isnt by any means gonna fix it but reading your post on this problem made me think of what I always do in these types of mechanical situations, I'd yank that carb off and go buy a brand new one and be done with it. After I count my time and money trying this, that and the other thing I finally go and get another of whatever and be done.

 

this carb cost me 250 dollars(canadian), theres no way im gona toss it and buy a new one. since rebuilding it didnt make a difference im pretty much ruleing out the carb as a suspect. im leaning towards the distributor being the problem and i might have to screw with the mechanical advance. i was out there with a timeing gun and noticed that the timeing didnt increase at all while slowly increaseing the throttle untill a certain point where it zipped off the timeing mark. any other ideas before i rip out my distributor?

 

sounds like "tip in" or w/e its called...someone more knowledgable can help. but i would check out timing and spark plugs

 

what exactly is tip in?

 

Won't Take The Throttle At Tip-in

At very low throttle openings (tip-in), the accelerator pump is not covering up for idle system problems. Now you see a sag or bog, then the engine picks up again as you open the throttle further. Richen the idle feed and fix the relationship between the throttle plate and the transition slot.

found that for info. maybe this will help

 

i tryed to richen the mixture and it still didnt help. sometimes it does accelerate normaly and smoothly, but about 80% of the time i get the flat spot and a bit of bogging. if i hold the throttle in that spot it will continue to run like garbage with a lower RPM than the actual idle speed and its just above the stalling point. as i said, it never did this before i put it in storage so is there something that im overlooking that might have got corroded or something? could this be a vacuume leak mabey?

 

vaccum leaks do all kinds of nasty stuff, thats all i know lol

 

How old is the fuel in the tank? When you rebuilt the carb, what did the fuel bowls look like? Any build up? On a similar note, have you checked fuel pressure during the bog down?

 

the whole carb was practicaly spotless. the fuel in the tank is fresh, ive been driveing it for the last 3 weeks. oddly enough it didnt start doing this untill after a few days of driveing it (after takeing it out of storage). the fuel pressure is at a steady 5.5 PSI, although i have been considering turning it down to 5 PSI just to test it.