Mechanics

ACCELERATION AND RPM ISSUE

2001 Chevrolet Blazer • 180,000 miles

In a 2001 chevy blazer, what would cause the rpm's to drop and have trouble accelerating past 25-30 mph?
Avatar
Problem2099
September 2, 2012.



There are too many possibiities to list. We need more information understand what could be possibly causing it.

Is the MIL indicating?
Check the catalytic converter and exhaust system for clogging.


KHLow2008
Sep 2, 2012.
The codes im getting are p0300, p0101, and when I checked it today I also got p0756


Tiny
Problem2099
Sep 5, 2012.
P0300 - Multiple misfires.
P0101 - Mass Air-Flow system Performance.
This should be the one causing the problem. Check the connectors and clean the MAF and retry. If codes still come back, you might need to replace the MAF.

P0756 - 2-3 shift solenoid performance or stuck off.
This is a transmission control problem which can be due to engine performance. Engine truoble codes takes precedence over other codes so we can leave this aside first.

Get the P0101 code resolved first and erase trouble codes and go for a test drive to see if the codes comes back.


KHLow2008
Sep 5, 2012.
Ok I did what you suggested and it seems to be the same. I also remembered that I had change the maf about six or so months back.


Tiny
Problem2099
Sep 6, 2012.
Did you clear the codes and are the codes the same?


KHLow2008
Sep 7, 2012.
I probably should have mentioned that, but yeah I erased the error codes and they are the same


Tiny
Problem2099
Sep 8, 2012.
The MAF is still throwing a code therefore you need to test the wiring, PCM and MAF itself.


KHLow2008
Sep 8, 2012.
And the best way to do that is?


Tiny
Problem2099
Sep 8, 2012.
Best way is to perform diagnostics with a scan tool and DVOM. Easiest way is to replace the MAF and hope that is the cause and nothing else.

Try this first.

Diagnostic Aids

Ensure MAF sensor harness is not routed too close to secondary ignition wires or coils, solenoids, relays, or motors. Check throttle plate for sticking, or deposits on throttle plate or throttle bore. A low minimum air rate through the sensor bore may
cause this DTC to set at idle or during deceleration. Check for any vacuum leaks downstream of MAF sensor. A Wide Open Throttle (WOT) acceleration from a stop should cause MAF sensor grams/second display on scan tool to increase rapidly. This increase should be from 6-12 grams/second at idle to 130 grams/second or more at
time of the 1-2 shift. If increase is not observed, check for a restriction in the induction system or exhaust system.

The Barometric Pressure (BARO) sensor is used in order to calculate the predicted MAF value is initially based on MAP sensor at key on. When engine is running, MAP sensor value is continually updated near WOT. A skewed MAP sensor will cause the calculated mass airflow value to be inaccurate. The value shown for MAP sensor display varies with altitude. With ignition on, and engine off, 103 kPa is the approximate value near sea level. This value will decrease by about 3 kPa for every 1000 feet of altitude. A high resistance on the ground circuit of MAP sensor may cause this DTC to set. Any loss of vacuum to MAP sensor may cause this DTC to set. A high resistance in ignition voltage circuit of MAF sensor may cause this DTC to set.


KHLow2008
Sep 8, 2012.