2001 Mazda Familia • 82,000 miles

Hi have a Mazda familia SP20, 2001 with 82000ks, oil and filter changed every 10000, run perfect for 4yrs but now having a problem, when you have been cruising along for a while and take your foot off the gas to let engine brake you when you get down to between 40 - 50 ks it almost stalls the effect you get is like going over rubble strips then its ok again? Also a few times after a journey when I come to a stand still it has cut out?
I have been running it on 91 fuel but someone has just told me it should run on 95, would this cause this and also would I have done any damage to engine running it on 91?
Any ideas
October 23, 2012.

91 octane should be fine as modern engine management system has the ignition timing controlled by the engine and the knock sensor would retard the ignition timing whenever necessary but then it also depends on the manufacturer's specification as different market might have different octane requirements. The owner's manual should have information on this.

As to the surging sensation and intermittent stalling, that should be due to the idle control system not working efficiently. The idle control air passages tends to accumulate dirt during engine operations and when excessive dirt has accumulated, the idle air passages would be restricted resulting in insufficient air getting past. Cleaning the throttle body and IAC would most probably solve the problem unless you have the Malfunction Indicator Light showing, which means there is an error in the engine management system.

Oct 24, 2012.
I am having this same exact problem. My mechanic said it was my air filter hose so I replaced it but it continues to happen.

Mar 17, 2015.