my mazda keeps stalling in idle

I have a 1992 se-5 and I put a 1988 engine in it. It ran perfect for about 2 months then I went out one morning and it stalls in idle. I replaced the router, cap, wires, plugs, and checked al the vacuum hoses and did the timing and it still stalls out.

You probably already checked this already but how does the air filter look?

air cleaner is new to

Well, the only 1988 engine that will fit in a 1992 is the B2200 engine, and you posted in the B2200 section, so that's what we assume (you didn't give full information, like stock carb or a Weber).

If mine, I'd check first the EGR valve, because if these get stuck open or partially open, the truck will stall out and not idle. The EGRs on these tend to stick after a while and need to be cleaned. Removal of the EGR is easy, 3 hex head screws using a 10mm socket, plus one vacuum hose and one electrical harness, but you can leave the harness connected to check it out. And with a hand vacuum pump you can check for the valve opening and closing too.

Many with Weber carb use an EGR block-off plate they readily make themselves from a piece of metal. Or an EGR in the closed position with the vacuum plugged can do the same.

If you have a stock carb, then there are some solenoids that open and close (or should), like to prevent dieseling/run-on, and if that doesn't open to let gas through, it won't idle.

Also, don't forget to check the choke operation. The choke heater plugs into the rear of the alternator.

Thank you. I have a 2.2 from a 1988 b2200 engine that I put in with the stock carb.
I will clean out the EGR value and let you know if it works. But right now if I idle it high enough it will keep running until I try to drive it and then when I push in the clutch it will stall.
Thank you for the info.

I cleaned out the EGR value and it helped it a lot but it still stalls. I checked the spark plugs again and the number one cylinder is not firing all the time and I do not know what is going on. Some times it will run great but most of the time it has a miss and stalls.