b2200 stalls out at hard stops

Just bought a 89 2.2, (my 5th :)) changed alot of basic stuff out(cap,rotor,wires,plugs, etc.) The guy I got it from couldnt get it to start for a long time, then he told me he changed out the needle and seat in the carb and it fired up. I cleaned it out (carb) and ran a tank of 93, but it still drops RPMs and stalls out sometimes on hard stops. If I coast there doesnt seem to be a prob. Any ideas? Idles a little rough too, I was gonna go pull an ECU from the junkyard for the hell of it, I dont know what else it could be. Float maybe? I seem to have a little mixing of gas and oil too I think, but it could be just old thin oil. Im changing it after I get done here.

BTW- 144K mi, doesnt blow smoke, timing belt changed 2x, tranny/rearend oil changed, routine maintenance up to par and everything documented, a steal for $600 woohoo

Dude, I Have exactly the same problem.

I bought the 90 model mazda B2200 with no options assuming it would get way better gas than my bigger truck. Well, It wouldn't start when I first got it and the guy told me it sat for 4 years. Well, the fuel lines were cloged and the strainer in the fuel tank wouldn't even pass air so I just took it off and installed a big fuel filter under the hood. Well, since then I broke 2 arms off of the mechanical fuel pump and bought an electric one from autozone. Well back to the problem. If I leave it at low idle, it idles fine until i drive it. Then when I let off the gas real fast or stop, it dies unless i give it gas, (which is hard to press the brake, gas and clutch at the same time). It Accelerates real well if you don't give it full throutle, but at full throtle, it kinda has no power at all.

I have tried to set the timing and adjust the idle higher but it still doesn't work right. I don't know how to fix it because I have never worked on an electrically controled carberator with tons of vacuume lines and lots of little electric vacumme control vaves. I did clean the needle and seat because it was flooding out at first. I also belive that it runs really rich because it only almost gets 16 miles per gallon which sucks for a 4 banger.

I thought about the computer or the idle air controle valve (if it has one). I also belive it could be one of those electrice things in the carberator, (don't know their proper names.)

If anyone out there has had these problems, It looks like we both need help. Im fixing to park it on the side of the street with the keys and singed title in it. (well not yet anyway)

Well, this truck is very sensitive to vacuum leaks. Try that first especially the ones in the intake manifold. Make sure every vacuum connection is connected and unused ones plugged.

On the carb, if the mixture valve has been tampered, you need to put it back to where it was. You can start at screwing it all the way in and back it out about 1-1/2 turns, then backprobe the O2 sensor with a digital meter and set close to 0.5 volts on a fully warmed up engine.
If the mixture is off, you will never get the truck to idle good.

Whenever you remove and reinstall the carb, you ned to disconnect the battery for 5 minutes then reconnect it so the computer relearns the new settings especially if you are switching a new carb.