alright so i have a 87 ss 305 5.0 H.O 4bbl v8 143xxx miles on it and its got a hell of a miss atleast i believe its a miss i could be wrong it could be tranny slip but ive never felt a slipping tranny so i dont know but i doubt it since it happens all the time no matter what gear its going into or where its at in the rpm field.
anyway like it said hell of a miss it jerks like hell while accelerating and even while just crusing i can feel it it got a still new rebuilt carb on it its a duralast carb new cap and rotor new plugs new wires oil changed at the intervals takes a while to warm up if i dont let it warm up for around 20-30 minutes i get no 4bbl accerlation access i can push it but it wont take off like a rocket as it should has a new egr valve aswell as new catalystic converter and tailpipes and mufflers since the old cat ate them thats all i can think of right now got any ideas let me know oh yea its got low power and gets horrid gas milage

 

well the lack of power may just be the fact that its a 305 not to mention a high mileage one. jerking or big hesitation under full throttle can be a timing issue. thats where i would start since you said its got new plugs, wires, and cap i would rule those out. i dont know if youre running a vacuum secondary carb or mechanical, but either way i would try and get the timing dialed in and then work from there.

 

My '84 Camaro has the 305 H.O. (not much for HP, I think GM rated it at 190HP).

I had a mis-fire on it before. Mine turned out to be plug wires arcing. Even though you put brand new ones on, that would be worth running the engine in the drive way at night and looking under the hood.

Also, since you changed the plugs, did you verify they were all properly gapped?

Another thing worth changing (if you haven't already) is the fuel filter. If your 305 H.O. is like my Camaro's (which has a Rochester Quadra Jet carb), I believe the fuel filter is in the front on the carb. Mine had an issue of low power and STALLING when my filter was failing.

 

i know the 305 is a pig but when i say lack of power i mean its lost some of the little power it had when i do get the 4bbl to kick in the engine comes alive it feels strong and powerfull but outside the 4bbl its im trying haul a tank with it i will have to check for arching and thats one of the things i forgot has new fuel pump not sure on filter tho have to take a look at it and i myself did not install the plugs so im not positive if they are gaped correctly i think some of my issue has to do with the pos duralast carb i have on it but the miss/jerk shouldnt be related to the carb ill have a local shop check my timing

 

Im sorry i got lost halfway through, prolly cause of he lack of punctuation.

 

still havent found the issue lol i still need to have the timing checked. i was out there tonight and i took off the air filter and i noticed like a brownish orange residue on the carb. anyone know if thats bad or not i dont know exactly what it is it didnt feel wet or fresh but i dont know. im going to change out the ignition coil soon and see if that helps any at all. i just want this thing to run the way it should

 

Is all the linkage on the carb working like it should be. My old truck had mechanical secondaries and one of the rods was hanging up so they wouldn't open. Also check the kick down cable on the transmission maybe its froze up. Just a few thoughts. It has been a long time since I worked on a carbed motor.

 

Carb adjusted once installed on engine?
Vacuum leak at base of carb or old/cracked vacuum hoses?
Spark plug wire crossfire due to improper routing?

Since you mention an extended warm up period I'd start with the carb adjustment. Rebuilt carbs are bench adjusted but need to be fine tuned to the particular engine they are installed on. They are not plug-n-play.

 

yea i deff think somthings up with the carb but i was out there today and found this steel accordian type tube coming off the air filter on the passenger side going down to a big hole on which was very hot lol. it has a big rip in it i wrapped it in duct tape and put it back down on there what is that for. it leads up to somthing on the airfilter that has a tube running off of it to some kind of device.

 

That is the heat riser tube. It's function is to prewarm the air. I think to help warm the car up in colder weather. I'm not sure where your located or if you drive in cold weather but I think you could plug it up.