93 240 Runs Great, Stalls after 30 minutes

sonnyseneker · Post by **sonnyseneker** » 01 Aug 2011, 07:31

I am getting my daughters 1993 Volvo 240 ready for her departure to college. Several weeks ago, the car started running rough and the ECU had a code of "1-2-1...Mass Air Flow Signal..Check Airflow Meter and O2 Heater Resistance". I knew the car had a rebuilt Mass Air Sensor so I purchases a new one . After installing the new one, the car ran better but had high idle and deleayed shifting. So, I removed the throttle body and cleaned it. I then losened the set screw, linkage and TPS. I adjusted everything in this order 1) the set screw, 2) TPS, 3) reninstalled throttle body and adjusted linkage, 4) adjusted throttle cable and then the kickdown cable. Tested the car....it starts fine with just the turn of the key, idles great and shifts great. However, after running it for 30 minutes or so, it will simply shut down at a red light or when pulling into a parking lot. When I say shut down, there is little warning....the dash board lights up like a christmas tree and the enginge is off. I can quickly restart it by "doubling footing" - one foot on the brake and one foot on the gas pedal so I can give it a little gas to keep it going. After restarting it runs great on the highway but you have to be prepared when you stop. To make sure I hadn't missed anything, I repeated the removal and adjustment of the throttle body 3 times and each time with the same results. The ECU is now giving me this code "3-2-2....Airflow Meter Hot Wire...(1) Check Airflow Meter"

Stats:
1993 Volvo240 Automatic with California Emmissions with 127,000 miles

New Parts: Brake Booster, Distributor Cap and Rotor, Spark Plugs, Air Mass Sensor, Flame Trap and related hoses, Fuel Filter, Head Lights, Side Ligths and Tail Lights

Recent Service performed by Me: **Throttle Body: Cleaned and then losened the set screw, linkage and TPS. In this order adjusted 1) the set screw, 2) TPS, 3) Reninstalled and adjuster linkage, 4) adjuster throttle cable and then the kickdown cable. **Removed and Cleaned the Idle Air Control Valve. **Changed the Oil, Oil Filter and Air Filter. **Replaced the vacuum line on the Fuel Pressure Regulator. **Replaced the Odometer gear. **Removed the temperature faker board and jumped pins 1 and 3 to restore the temperature gauge to normal operting mode. **Installed new rear Shock Absorbers. ***Installed new O2 Sensor a year ago, Bosch Sensor had the wrong plug so I had to cut the car's plug and the sensor's plug off and splice the wires.

Service by an authorized volvo mechanic (6 months ago): Replace Rear Seal, Installed a Transmission Kit and New Engine Mounts.

Note: Each time I service the car, I always disconnect the battery cable for 2 reasons 1)For protection of the electrical system. 2) I know that to properly clear any trouble codes that the cable needs to be disconnected for at least 10 minutes.

Does anyone have any advice? I am afraid for my daughter to drive the car like it is.

Post by **jimmy57** » 01 Aug 2011, 10:01

Inspect the connectors in the MAF sensor harness plug for looseness. Inspect the hose between the MAF and throttle for cracks.
when engine is hot to the temps when this occurs make sure you still can hear the idle microswitch close. The linkrod can hold it open a bit if too tight and the throttle switch adjustment routine wants the TPSW set to be closed with .20mm and open with .30mm feeler gauges between stop screw and throttle arm. Temp can cause some of the components of throttle to grow and contract with temp changes so a "hair trigger" adjustment of TPSW can make for non-functioing idle microswitch when engine warms up or it gets to freezing temps.

sonnyseneker · Post by **sonnyseneker** » 01 Aug 2011, 11:17

Thank you for responding Jimmy. This is procedure I used to adjust the set screw and TPS. Let me know if you agree with the process.
With the Throttle body off, I loosened the set screw and TPS. I then held the throttle plate closed with one finger. I started turning the set screw in until i could just feel the throttle plate barely move. I then turned the screw another 1/4 turn and tightened the lock nut. For the TPS, I again kept the throttle plate closed using one finger and rotated the TPS counter clockwise until I heard the click. Using very slight pressure, I carefully kept turning it counterclockwise until it stopped and I tightened the screws. For the link rod, I adjusted it so that there is a slight gap between the black throttle spindle and the stop.

I am a novice at this and some of the terminology gets away with me.

sonnyseneker · Post by **sonnyseneker** » 05 Aug 2011, 05:39

I took my throttle body and IAC off the car to take them to a German Volvo Mechanic (he owns his own shop). He checked the IAC and the TPS to ensure they are working properly and then adjusted the set screw and the TPS on the throttle body.

When I picked it up, he showed me how my method of adjusting was not creating the correct spacing around the butterfly. I had to beg him to let me pay him and he kept saying it didn't take him any time "so not to worry". I finally convinced him to accept some amount of payment and he let me pay him $20 bucks.

I put everything back on the car, drove it around town and the interstate for over 2 hours and it runs perfectl