CarburetorsCarb discussion and questions. Upgrading your Third Gen's carburetor, swapping TBI to carburetor, or TPI to carburetor? Need LG4 or H.O. info? Post it here.
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Hey guys i just bought an 85 t/a with a swapped 350. I have a problom with the check engine light. When i checked it, it was giving me running rich then running lean?????WTF. then my nest question is when im in first (5-speed) i slam the gas it bogs down for like 2 secs and then THROWS your *** in the seat i was wondering if there was any way to stop that throwing. I have no expierence in carbs but i plan on going to school for it next semester. i have searched and read a few threads but no luck. Also a guy at advance auto said it could be my accelerator pump....no idea any help would be great
The bog is the secondary air valve opening too quickly. Usually caused by a failing choke pull-off (which holds the air valve closed until manifold vacuum drops). Could also be the AV tension adjustment - see the tech article linked from the thirdgen.org homepage (also linked in the "welcome to the carb forum" sticky) on that adjustment.
Check the choke pull-off. You need a hand vacuum pump (like a Mity Vac) to do this so you can verify it pulls in and holds vacuum when you aren't pumping.
Checking the accelerator pump is easy - with the engine not running, remove the air cleaner and hold the choke butterfly open. While holding the choke butterfly open, look down into the front venturi and open the throttle with your other hand. You should see a squirt of gas into each of the small (primary) venturi while the throttle is opening.
But, with the description of the symptoms you provided, it ain't the accelerator pump.
ok like you said the accelerator pump isnt bad me and my buddy both saw gas coming out, but would anything else be cause such bad hesitation when i start it up in the morning or when i give WOT?
ok like you said the accelerator pump isnt bad me and my buddy both saw gas coming out, but would anything else be cause such bad hesitation when i start it up in the morning or when i give WOT?
read the thread again...five7kid already told you.
... would anything else be cause such bad hesitation when i start it up in the morning or when i give WOT?
You hadn't mentioned a hesitation when first started in the morning.
What air cleaner is on it? The stock air cleaner has a "thermovac" system that closes off a flap in the snorkel and routes warmed air from around the exhaust manifold into the air cleaner. If that system isn't working or parts of it have been removed, off-idle will be very poor until the engine fully warms up.
Your choke may also not be closing properly, or the choke pull-off is opening the choke butterfly too far (it can do that even if it is releasing the air valve too soon). The choke pull-off opening is adjustable.
ok let me start off this way. i bought the car about a month ago and have cleaned it up and have performed the maintinence. It had a circlular moroso air cleaner on it when i bought it. Now it has an edelbrock "pro flo". also i have a big gapping hole in my crankcase and supposidly there is a crankcase filter but when i got one about a mile down the road i smelled burning rubber and it was smoking real bad so i took it off and have an open crankcase...lol. also it looks like i have everything from hoses and lines except for a thick hose that comes off the block and leads to nowhere and was cut by the previous owner. it also smoke real bad after siting over night but thats it, me and my dad figured it was just gas build up in the carb. so any advice would be great.
Around these parts that air filter is known as "the triangle of death". You're better off with a stock air cleaner. The one you took off is the 2nd best choice but will lead to that dead spot when the engine is cold, especially in cold weather.
I haven't heard anything back about checking the choke or choke pull-off operation. Setting the carb to factory specs is always a good first step.
