My 2000 Protege DX, 1.6, 5 speed, 117,000 miles bogs on the subtlest of inclines. On a level or down hill road it runs like its normal, underpowered self. But even the incline of a freeway on ramp causes the car to bog like I am one gear too high for the conditions (even though its not). This has occurred almost undetectable over time. It is not something that just started one day.
There is virtually no torque out of the motor and acceleration is extremely slow until about 3,000 RPM. From 3,000 RPM onward the car accelerates like it should and at about 4,000 RPM acts like a carbureted engine with the secondaries having opened (the power picks up considerably). This is driving me nuts.
For the record, the car recently passed a California smog check which loads the engine on the dyno. The results across the test ranges were only about a third the way to the limit. This does not seem to indicate any engine problems. The car has NO codes (and never has). It idles fine. There is no miss. It doesn't really stumble either. It just bogs until it approaches 3,000 RPM.
The air filter (Wix) and plugs (NGK) are new. The timing belt I replaced about 15K ago. There are NO air leaks. I replaced the large MAF to throttle body hose a while back. The O2 sensor is new (Denso). I removed the fuel filter and found it immaculate. I did find some minor "slime" around the fuel pump inlet and removed it. I also flushed the pump and while having no official pressure test it did flow exceptionally strong to the eye and finger. Even though the MAF looked clean I used an appropriate cleaner on the elements. None of these replacement items/ fixes changed anything.
Since the car idles fine - and will accelerate normally from about 3,000 RPM to the redline there is no indication that fuel/air delivery, spark, or a clogged CAT/exhaust are the problem. If those things are at issue the car would be incapable of that. Also an air fuel ratio issue would have shown up in the smog test that was easily passed.
So, I'm baffled because acceleration (on an incline only - be it ever so subtle) is mercifully slow until about 3,000 RPM. And sadly virtually every "natural" shift point (the 1 to 2 shift being the worse) drops the RPM to around 2,000 RPM. Then it struggles back up until 3,000 RPM. I have to wind the motor up to 5,000+ RPM - then shift (dropping closer to 3,000 RPM) to have any hope on inclines. Once I crest the smallest of hills everything is fine again.
I've looked around on Mazda boards and there are others with the same complaint. So, I know it is just not me. However, there are really no answers either. Anyway, hoping for direction. Thanks for reading my problem. Tom
There is virtually no torque out of the motor and acceleration is extremely slow until about 3,000 RPM. From 3,000 RPM onward the car accelerates like it should and at about 4,000 RPM acts like a carbureted engine with the secondaries having opened (the power picks up considerably). This is driving me nuts.
For the record, the car recently passed a California smog check which loads the engine on the dyno. The results across the test ranges were only about a third the way to the limit. This does not seem to indicate any engine problems. The car has NO codes (and never has). It idles fine. There is no miss. It doesn't really stumble either. It just bogs until it approaches 3,000 RPM.
The air filter (Wix) and plugs (NGK) are new. The timing belt I replaced about 15K ago. There are NO air leaks. I replaced the large MAF to throttle body hose a while back. The O2 sensor is new (Denso). I removed the fuel filter and found it immaculate. I did find some minor "slime" around the fuel pump inlet and removed it. I also flushed the pump and while having no official pressure test it did flow exceptionally strong to the eye and finger. Even though the MAF looked clean I used an appropriate cleaner on the elements. None of these replacement items/ fixes changed anything.
Since the car idles fine - and will accelerate normally from about 3,000 RPM to the redline there is no indication that fuel/air delivery, spark, or a clogged CAT/exhaust are the problem. If those things are at issue the car would be incapable of that. Also an air fuel ratio issue would have shown up in the smog test that was easily passed.
So, I'm baffled because acceleration (on an incline only - be it ever so subtle) is mercifully slow until about 3,000 RPM. And sadly virtually every "natural" shift point (the 1 to 2 shift being the worse) drops the RPM to around 2,000 RPM. Then it struggles back up until 3,000 RPM. I have to wind the motor up to 5,000+ RPM - then shift (dropping closer to 3,000 RPM) to have any hope on inclines. Once I crest the smallest of hills everything is fine again.
I've looked around on Mazda boards and there are others with the same complaint. So, I know it is just not me. However, there are really no answers either. Anyway, hoping for direction. Thanks for reading my problem. Tom