1.8 V-6 engine acceleration problems

[Tom]

Hope maybe someone can help me out.<BR>Have a 92 Mazda MX-3, 145,000 miles, engine cold don't have any problems. After warm(5-10min) it bogs out in 5th gear at 35mph when I press the gas only 1-2 inches down. Not WOT, but problem doesn't go away even when I fully depress the pedal. The acceleration feels as if it is running on less cylinders until I let up and the engine gas back to smooth acceleration. I've noticed right off from a start is slightly bogs out if I don't bring the rpm a little higher than normal when letting out the clutch. It gets to be a safety concern when I need to get out in traffic and it bogs out in 1st or 2nd when I need to get on it. <P>I appreciate any suggestion or advice. Thanks

[pelado]

It's always tough to diagnose stuff like this via email. Personally I wouldn't be in 5th gear at 35 mph, bogging would be a fact of life with a 1.8 liter V-6 at low RPMs in high gear!<BR>But if you're experiencing bogging all the time, then I would check out your Throttle Position Sensor (TPS). Once again I'm guessing [img]shrug.gif"%20border="0[/img] and I'm assuming everything else has been checked and the engine is well maintained. There's an online shop manual on mx3.com, look at the section for verifying the TPS is working properly. You'll need a digital voltmeter.<BR>Good luck!

[David Coleman]

Check your hoses for vacuum leaks.

[Tom]

The engine is all tuned up, new plugs, wires, cap, and rotor. It's not lugging at 35-40mph, I can see why if you have it floored but to give it 1-2 inches of gas <BR>and have the engine take a nose dive like it just cut out 2-3 cylinders and as soon as you let off the gas those 1-2 inches it smoothes out. Also when you get on it from a start, it boggs out. If you let off a little it smoothes out. From idle there is a delay in rpm if you goose it real quick and then it rises in rpm.

[back alley]

check for a bad plug