Recently did my clutch and the car ran fine before this with out any issues other than clutch slippage. After i got it all back together it had a stutter and then i figured out that since i bought it the plugs were switched(yet it ran fine) and the plug wires were old and junk so they got replaced with Mazdatrix Wires. I also threw in some Heet and STP Injector Cleaner.

Now the car idles fine and revs fine when at a dead stop. When driving its fine all the way up to 4500rpms and then from 4500rpms on it will studder/hesitate in 1st-3rd(haven't tried 4th). When it does this it make a pop which i am determining as a backfire. I am 99% sure it isn't my grounds as I re-grounded all the things listed and then some from Aaron Cake's site.

Anyone have any ideas what could cause this?


BTW what is the difference between NGK Platinum and NGK standard plugs?

 

check your gas tank see if there is crud in the bottom where the fuel pump sock goes if its a dark brown or black clean out the gas tank and get a new fuel filter and feul pump sock

 

I'd check the timing as well. I was gonna say cat's, but I can see that they are gutted.

 

the fuel pump thing sounds about right. I was told a while ago that my sending unit was on the way out because my gas gauge doesn't fully work and my low fuel light doesn't work either. Do i have to drop the tank on my vert to check/change the sending unit? I know there is a few screwed in plates above the tanks but i have never removed them.

 

got a newer pump and sending unit. Problem is still there but gas gauge works 100% now.Gonna check the timing tomorrow along with rechecking all the grounds. Chime in for more suggestions

 

could it possibly be gassy oil? i smelled my oil this morning before coming to work and it smells pretty gassy. Im plan on changing it now. I do know why it smells like that though.

 

Ok changed the oil and ordered new plugs. Problem persists and new plugs will go in tomorrow. Also ordered a coolant hose that is leaking doubt that is the problem though. Anyone have any other ideas??????

 

turned out to be the spark plugs just to help anyone else that encounters this problem