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I'm trying to track down a hit and "miss" problem.My 1.6 ,5 spd. runs great most of the time,but off and on it will start to stumble,back pop and lose power for a few seconds to a minute or so,then take off and run great again.It does whether your driving or it's just sitting in the diveway running.I"ve tried gas treatments,draing and refilling the tank with premium.And it still does the same thing.Also,checked the cats and found no blockagesI have great exhaust flow.Any ideas????

Check grounds? Corroded battery terminals?

Clean terminals,new optima battery.I did notice while driving it today,that it puffed some black smoke out a couple of times,like it was running rich.I checked the MAF connections and cleaned it with some CRC MAF cleaner,re-assembled and it's still doing the same thing .Any other suggestions or Ideas would be greatly appreciated.

P.S.,I did not notice this stumble or back pop at highway speeds above 70mph.An occasional hesitation,but minimal.

PURPLEFLEA wrote:P.S.,I did not notice this stumble or back pop at highway speeds above 70mph.An occasional hesitation,but minimal.

There's your fix! Just keep it over 70!!!

Id start by replacing all the vacuum hoses, just to be sure. Then, get a manual and a multimeter and test all the sensors, especially the MAF and the TPS. Also, you should check the fuel pressure, and replace the fuel filter, if you didn't already.
Let us know how it goes.
Good luck.

id check your EGR first... did you check for codes using the GND and TEN pins?

if your cruising at lets say 50 consistently. and periodically your getting a miss, if your tach is dying when it misses then it could be your distributor clip. i had this happen on mine where i would be cruzn along and the rpms would drop for a split second then it would act normal. i replaced the clip. could be your problem