My car will not go past 4,000 RPM anyone could help? any questions?

 

is it an auto? what year?

if an auto, check the kickdown linkage, see if its stuck. that will cause it to only go to 4k.

 

5 speed..... 420A motor, say im in 3rd gear and im close to 4 grand and i drop it to 2nd and its at 6 grand it will go past that,,,,but as soon as i hit the gas it bogs horribly, like im hitting rev limit

 

Check the codes. If it has gone into "limp-in" mode, the rev limiter comes on much earlier. Certian sensors will trigger it.

 

limp in mode? i've never heard of it, could you describe what it does?

 

i talked to my mechanic ... hooked up the scanner only one code came out which which was an O2 code.

 

Engine sensors are devided into 2 groups, primary and secondary. The PCM has 3 programs in it to run the engine.When allthe sensors are working properly the PCM is in "RUN" mode. If a primary sensor fails, like the crank position sensor, the PCM changes to "STOP" mode.When a secondary sensor fails, like a temperature sensor or an o2 sensor, it goes into "LIMP-IN" mode.The PCM allows the engine to run, but in a low power mode. It changes the timing table,reduced rev limiter, and brings the mixture up. Until the sensor is fixed, it will stay in this mode. Ihad aDaytona go into this mode whenthe MAP sensor went out. My brother-in-law works at Chryslerwriting the engine control programs and explained it to me.Although he didn't write the engine controls for Neons,most Chryslers pretty much work the same.