I have a 1989 Mazda 626 4 cylinder automatic, That when just starting it and putting it gear it runs fine, but once it runs for a while it surges and the RPMs drop and it cuts off while I have it in drive or any gear. I have check the fuel filter. I have check the spark plugs. They both look fine. Someone please give me a clue to what it may be.

 

do you have a check engine light on, what does it do out of gear in idel, and does it overheat and will it start right back up after it dies on u, get back to me and then i can give u some answers

 

When it is out of gear in idel, It runs fine. No I dont get a check engine light. No it not overheating. It starts right back up with no problem after it dies on me.

 

tell you what if you take and set the e brake and put it in geaR, see if it dies rigjt away if not disconect your idel air control valve {iac} ( its a cylinder shaped valve with a wire hookedto the throtle body) with this dsconected u can try to turn the idel up on its own therefor the car will idle wihout the ecu and on its own make shure to ha ve it set about 1000 to 1100 rpm for when gear is engaged and if iiut stops stalling you have a bad iac valve