RPMs fluctuating

LOVINLIVIN007

MEMBER
2001 ACURA MDX
6 CYL
AWD
AUTOMATIC

I have a 2001 Acura MDX with 120,000 miles and well maintained. The rpms fluctuate rapidly about 50 or so when cruising between 1200 - 1500 rpms in 5th gear and not in the other gears. I have tried to remedy the problem by changing transmission and transfer case fluids, spark plugs, and EGR valve. By my research, I believe the problem is the torque converter but would like to know for sure before I pay that much money. What else could cause this problem?

1 Reply

BMRFIXIT

MECHANIC
19,053 POSTS

Check this TSB 1st
IDLE FLUCTUATION
TECHNICAL SERVICE BULLETIN
Reference Number(s): 04-003, Date of Issue: February 6, 2004
ACURA:2001-02 MDX
CATEGORY:Engine
APPLIES TO:2001-02 MDX - ALL

Related Ref Number(s): 04-003
ARTICLE BEGINNING
SYMPTOM
The idle fluctuates, and the MIL is on with DTC P1129 [high manifold absolute pressure (MAP) sensor signal] set.
PROBABLE CAUSE
The idle air control (IAC) valve is faulty. The IAC valve sticks open and creates a higher manifold pressure than expected, causing DTC P1129 before P0505 (faulty IAC valve) is registered.
CORRECTIVE ACTION
Check for DTC P1129 and P0505. If both are present, or the idle fluctuates, replace the IAC valve.
PARTS INFORMATION
Valve Set: P/N 16022-P8A-A03
WARRANTY CLAIM INFORMATION
WARRANTY CLAIM INFORMATION
OP#DescriptionFRT
123503Check for DTC P1129 and P05050.3
121187Replace the IAC valve0.7

Failed Part: P/N 16022-P8A-A02
Defect Code: 03001
Symptom Code: 03203
Skill Level: Repair Technician
Out of warranty: Any repair performed after warranty expiration may be eligible for goodwill consideration by the District Parts and Service Manager or your Zone Office. You must request consideration, and get a decision, before starting work.
REPAIR PROCEDURE
Connect the HDS to the vehicle's DLC (data link connector), and check for DTCs. If DTC P0505 is stored with P1129, or the customer complains the vehicle idles at a high rpm or the idle fluctuates, replace the IAC valve (see page 11-142 of the 2001-02 MDX Service Manual).
On the HDS go to the MODE MENU to reset the ECM/PCM.
Do the idle learn procedure.
Make sure all of the electrical accessories are off, then start the engine and let it run until it reaches normal operating temperature (the cooling fan cycles twice).
Let the engine idle for 10 minutes with no load.
Check the DATA LIST on the HDS to confirm the MAP sensor is working properly. The MAP sensor reading should be under 1.1 V. If the reading is over 1.1 V, refer to the service manual for normal troubleshooting.