E 150 1/2 Ton Van V6-4.2L VIN 2 (1997)
Intake Manifold: Customer Interest
EGR - MIL ON/Hesitation/Misfire/DTC's P0305/P0306 Set
Article No.
98-26-13
01/04/99
^
HESITATION - HESITATION ON ACCELERATION -
VEHICLES WITH HIGH ODOMETER READINGS
ONLY EQUIPPED WITH 4.2L ENGINE
^
MALFUNCTION INDICATOR LAMP (MIL) - MIL
ILLUMINATED WITH DIAGNOSTIC TROUBLE
CODES (DTCS) PO3O5 AND/OR P0306 STORED IN
MEMORY - VEHICLES EQUIPPED WITH 4.2L ENGINE
^
MISFIRE-OFF IDLE MISFIRE - VEHICLES WITH
HIGH ODOMETER READINGS ONLY EQUIPPED
WITH 4.2L ENGINE
LIGHT TRUCK:
1997 ECONOLINE
This TSB article is being republished in its entirety to revise the model coverage.
ISSUE
A hesitation on acceleration lust off idle and misfire complaints with Malfunction Indicator Lamp (MIL) illuminated may occur on some vehicles with
higher odometer readings. Diagnostic Trouble Codes (DTCs) typically are P0305 or P0306 (misfire). This is NOT a low odometer issue and most
vehicles have accumulated well over 80,000 kilometers (50,000 miles) before this condition is experienced. This condition may be the result of carbon
contamination in the Exhaust Gas Recirculation (EGR) ports in the lower intake manifold. The contamination may direct uneven amounts of EGR gas to
certain cylinders. This condition has been observed mostly on vehicles used in commercial applications that are subjected to extended idle conditions,
high sulfur content fuel, and/or extended oil change intervals.
ACTION
Follow normal diagnostics for misfire codes and hesitation in the Powertrain Control/Emissions Diagnosis (PC/ED) Service Manual to ensure that all
other systems are operating normally. After normal diagnosis and concern is not resolved, refer to the following Service Procedure. This Service
Procedure is to aid the technician in finding a difficult to correct miss.
SERVICE PROCEDURE
1.
Perform normal diagnostics for misfire codes and for hesitation complaints including Pinpoint Tests found in the PC/ED Service Manual. Take
corrective actions as indicated by diagnostics.
2.
On 1997 units built prior to 4/16/1997, check to see if TSB 97-12-9 has been performed. If TSB 97-12-9 has not been performed, perform it.
3.
If concern has not been corrected in Steps 1 or 2, remove vacuum signal hose to the EGR valve, cap off hose, and increase engine rpm off idle to
determine if condition is corrected.
4.
If Step 3 corrects the condition with EGR disconnected, remove the upper intake manifold and inspect EGR ports for carbon contamination. If
contamination is present that could disrupt EGR flow (some contamination is normal), clean all ports using a pick and solvent. To service the
upper and lower intake manifolds, refer to appropriate Service Manual.
NOTE
DO NOT REMOVE UPPER INTAKE MANIFOLD UNTIL YOU HAVE COMPLETED THE SERVICE PROCEDURE. FIELD EXPERIENCE
SHOWS THAT CARBON CONTAMINATION OCCURS IN ONLY A FEW INSTANCES.
OTHER APPLICABLE ARTICLES: 97-12-9
SUPERSEDES: 98-25-12
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 609400, 609600, 611000, 698000
