We bought this 01 MPV new LX 2.5L engine (Ford engine?). Overall the van has been good. Since my 70K Mazda dealer maintenance there has been a jerking like the timing was off. [ol][*]Two weeks later after Maintenance van started jerking when going from stop to 20MPH however no engine light indicator. Mazda dealer replaced coil, plugs, and paid for new spark plug wires dealer installed and all was well. Extended warrenty covered part of repairs but I had to pay the rest.[*]Then a week later it started jerking again with engine light, per local dealer service dept. spark plug #2 misfired. Replaced the coil, spark plugs. dealer warrenty.[*]This week same issue. This will be fourth time for same issue my MPV in service since 70K maintenance in less then two months. UPDATE: another sparcplug had carbon clogged + sparc plug wire had trace of carbon. dealer says that may have caused electirc short in this case. Replaced.
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It appears that Mazda dealer not able to find root cause. Per dealer the computer shows everything is OK. I found on web a similar problem with one other MPV owner.

This thing got me interested in digging for more details related misfire issues.Is there service bulletin related to sparc plug misfires on MPV 01?

 

I was at dealership and chatting with other service manager. I believe got a reasonable explanation from second dealer service manager on this problem. He had same issue with one other MPV before. It all comes down to bad Motorcraft brand sparc plugs mostly cracked plugs. All work is warranty 12 months 12K mile so if a new sparc plug goes bad my option is to take it back to dealer.

It appears that Mazda dealer aware of this but there is no alternative since they have to use Motorcraft brand sparc plugs.

 

It happend again got blinking check engine light with hick ups when accelerating over the weekend. This is a fifth time taking to delar in three months..... When I was dropping off at dealer noticed new Mazda5 in lot and it looked nice with 4 cly. engine.

 

I've used Motorcraft plugs for years. Never had a problem. When the dealer worked on your truck, did he replace all 4 plugs each time? Or did he only change the one plug that was mis-firing? Typically, when 1 plug goes bad, the others aren't far behind. Spark plugs do wear over time (electrode gets eaten away - this is true for all brands of spark plugs.)

Did they properly gap the plugs prior to installation or did they just slap them in from the box?

 

My understanding is dealer replaced only defactive plug(s) not all six. Dealer says the only fix what's computer diagnostics shows. The MPV is at 73K and all plugs and wires have been changed during 71K service.

Per one dealer service manager the Motorcraft plags are factory gapped properly for MPV no manual gapping required.

I am now thinking there may be some other issue that is causing misfiring and plugs going bad.

 

I don't care for the "no gapping required"....I always gap my plugs (all plugs are "pre-gapped" from the factory, with varying degrees of success based on the plugs I've seen, and I've seen a ton of them.)

It's also possible you have water in your gas tank (condensation)...Put some "dry gas" (ethyl alcohol) in your tank and run it as low on fuel as you can. Then fill up with premium fuel and another dose of dry gas. I've had that happen on a couple of vehicles I have owned over the years.

 

Update: I have been driving without problem for three+ months after last sparc plug replacement. The problem appeared to be related defactive saprc plugs.................

This is just one of the situations you go through in a lifetime, and you always learn new things about automobiles....

 

I am glad this wasn't the case.

 

I hope dealer has double checked gaps with all sparc plugs in my vehicle.