im new to the forum i need help

I have an 87 mazda b2200 carbed and i have a missfire at idle ive rebuilt the motor replaced the carb cleaned the egr valve replaced the fuel filter fuel pump plugs wires coil rotary button rotary cap and i still have this missfire onley at idle im not sure what to to from this point. Thank you in advance for any help

Vacuum leaks? Idk just throwing that out there. U running all stock or webbered?

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I can't remember which it is, but someone can help you on this one - intake manifold gasket, when it leaks, you either get a misfire ONLY at idle or ONLY under stress. I believe it's only at idle, because there is so much lower vacuum. Might be worth checking out.

Im running the stock carb i wanted the webber but my step dad was working on it at the time so he made me shove out three hundred dollars for another stock carb.thanks for the idea on the intake manifold gasket ill replace that i just replaced the o2 sensor still missfires

I havnt found any vacuum leaks but thanks for the idea id there any main vacuum lines i can cap off to se if that improves the idle?

I personally wouldn't not with the stock carb... Is the carb brand new or used/remani?

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do you have a lot of oil in your air cleaner housing coming from the hose that runs to air housing from valve cover? if so that indicates high blow by wich i have recently learned from this sight is exhaust gases and such "blowing by" the piston rings due to worn or cracked rings witch can cause a slight idle misfire that is un noticed while driving but heard while idling. just a possibility. also read somewhere that misfire/sputtering could be caused by a lean fuel air ratio due to vacuum leak (witch most likely not as you've checked for leaks) or a poorly tuned carb (stock carbs need almost every sensor and vacuum hooked up properly to run right) i have heard of people capping all the vacuums and tuning the carb by the screw that is blocked by a removable tamper pin. sum unplug the ecu under passenger kick panel and try tuning the screw that way. just a few things ive learned maybe they can help u.

The carb is a used rebuilt carb from a shop in tampa i had to replace the original carb because the solinoid inside the carb shorted out and caused the truck to stall running down the road it would start up but once you started going down the road it would die. And i just rebuilt the engine less than about 14 000 miles ago but ill check the compression i think i found a vacuum leak at the back of the carb on the intake manifold. But its hard to get to

Ive been wanting to remove all the vacuum line that run the carb but have been afraid to because ive gotten mixed ansers on what would happen this is my onley vehicle so i cant afford to have it not running how would removing the vacuum lines affect my truck i just wanted to keep the lines to the brake booster the advance and the idle up solenoid for the ac also would having to hold the gas peddle half way to get the truck to start when warm be a sighn of a vacuum leak the choke is open sorry for so many questions

Hey motley... Vacuum lines are there for a reason so I wouldn't just pull them off because you feel like it, especially with running the OEM carb.

If you convert to a weber you can gut all the lines except a couple.