mazda runs lean after 4k rpm...HELP!!!

[NosVette]

As the title say you guys my mazda runs fine and good till you go past 4k rpm or if you just floor it is wants to just quit working the car is a 92 mx3 with a klde swap its my only car for right now I need it to go to work and places if someone could help me out that would be great.

[Five*Star*]

Does it do it in any gear, or all gears? How do you know for sure it's leaning out? Have you pulled the plugs already?


How many miles have you put on the car, and what maintnence has been done?

[NosVette]

Does it do it in any gear, or all gears? How do you know for sure it's leaning out? Have you pulled the plugs already?


How many miles have you put on the car, and what maintnence has been done?

It does it in neutral and all gears im sure its leaning out because I have the Air/Fuel ratio guage and its in rich and stoich at idle and/or when you accelerate lightly but if you floor it and keep the gas pedal to the floor it leans out and the idle just sits jumping around 1krpm-2krpm as if it has a big cam or sumthing.Or if you accelerate lightly the idle goes on smooth til around 3.4k-4k rpm and it starts to choke or sputter or what ever its doing and/or if your accelerating lightly and its around 3k rpm and you just floor it the car just dies to 1k rpm and starts jumping the idle as stated in the previous sentences.any help would help thanx...

[Five*Star*]

You are likely losing:

A) voltage/amperage to the pump

B) pulse/trigger signal to injectors and/or ignition

C) ignitor or coil

D) air leak in MAF system or intake manifold


It sounds mostly like a trigger signal to me if idle is fluctuating, or a vacumm leak.

This is a MAF car??

[NosVette]

You are likely losing:

A) voltage/amperage to the pump

B) pulse/trigger signal to injectors and/or ignition

C) ignitor or coil

D) air leak in MAF system or intake manifold


It sounds mostly like a trigger signal to me if idle is fluctuating, or a vacumm leak.

This is a MAF car??

Yeah uts a MAF car what do you mean by trigger system???

[blackshine007]

Didn't I tell you to check your O2 sensors? I know I mentioned something about that. Another thing, if you have the VAF sensor too tight arond the plunger, it could be getting stuck and not fully open or close all the way. So when you get the time, make sure that it's fairly snug around that plunger.

[kfzemx3]

1st off if you just have a Air/fuel hooked up to your stock sensors its basically worthless, more for the effect than fact. Get a Pyrometer or spend the money and get a wide band.
This is interesting though I've never herd of a k series running lean lol, they always run rich.

[wanksta]

try replacing the fuel filter?