A bit more information would be helpful. Did this begin suddenly? Does it only misfire under load, acceleration, speed, ect., what conditions? Mileage, filter changes, repair history? Who checked the fuel pressure? It's fifteen years old and it could be one or many things.
Nobody can analyze a problem in a NG. I would suggest the vehicle be hooked up to be analyzed to determine the cause.
I would take it to a Ford dealer, Ford built your truck, at their Metuchen NJ plant. The shop rates are generally $10 to $15 an hour lower at Ford dealers than Mazda dealers. ;)
Just came from Mazda Dealer and they said, it could be fuel pump because pressure should be 40 psi, not 22. Secondly could be distributer causing problems. They say it could take 1-4 hours to diagnose, then more hours to repair.
I thought 22 PSI was a little low, which is why I mentioned that it should be checked. Proper diagnosis entails hooking up a fuel pressure gauge to measure pressure, and then measuring fuel volume delivered in a beaker. You could also have a clogged fuel filter or fuel pump pickup screen.
I suspect that you have both a fuel delivery problem that is causing reduced performance but not the bucking, and an ignition problem is causing the bucking.
1-4 hours to properly diagnose seems reasonable to me.
22 psi is low, and should be 40 psi according to mazda dealer. I will need a new fuel pump installed.
You
Fuel pressure was done w/o fuel filter hooked up. Will be installing new fuel pump as well.
According to mazda, the low fuel pressure can cause the truck to run sluggish, and back fire.....in other word run like a bag of dirt. I'm not convinced the fuel pump is causing all my problems. I guess I'll know when I change it. I will update you at that time.
At about 75 dollars canadian, I'm not sure if that's feasible for a diagnosis which still may be wrong.
Yes Mazda dealer installed distributer cap/rotor button, but had to replaced it again the other day with Canadian tire product. The name escapes me now........it's orange and white box. To be honest, I'm not convinced that either the rotor button, cap, wires were causing any issue. I changed the plugs because they were satched with gas due to flooding it trying to start it numerous times. (it was parked and not started for about 3 months or less)
I intend to have the fuel pump replaced next week. Hoping for the best! Cost of fuel pump is $200.00 (garage cost), not OEM) I will also be having the unit redone at cost of $100.00. The add installation on top of that.
If your truck is not a Ford Ranger, than it must be one very old truck, built back when Mazda was making small trucks in Japan for Ford, out of the B1600. ;)
I think you would have been better off staying with the Mazda branded ignition parts instead of aftermarket, but don't change them unless you still have the old parts.
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