Hi, I'm new to this forum. My newly licensed 16-year old just bought a 2-owner '84 244 DL w/ 129K miles. (Sweet!) We are working through some known issues, but the car has been running fine. However, with the onset of Seattle's cool, rainy, fall season yesterday, he had problems starting it. It turns over, but stalls after just a few seconds. Even with giving it gas, it runs rough and stalls as soon as you take your foot off the gas. I suspect it may be related to the idle air control valve or the temperature control sensor. Previously, my mechanic has recommended replacing the PCV breather box, but I'm not sure if this would cause idling issues.


We love this car, and are on a steep learning curve regarding the quirky nature of a 34 year old Volvo.


Any advice is greatly appreciated.

Thanks everyone for the responses. It turned out to be the Air Mass Meter. When I unplugged the connector on top, the car did idle, but it was rough, indicating that the unit was sending incorrect data when connected. Got a new replacement, and installation was simple. Now it starts right up, and idles fine. I learned that some fine tuning of the unit is necessary, even though the car runs fine right now. Will take care of that when I do a tune up in the next few weeks.

Hi,

A bad or sticking idle control valve will exhibit its faults by not rushing the idle up higher than normal idle upon first starting. It does this for a second or so before making it idle at 750 rpm.
These cars should start without ever touching the gas pedal. The IAC does the extra air for you and then shuts it down.

The mechanic may have seen extra gunk in the throttle body plate area or in the snorkel tube behind the AMM warrant the consideration of new clean parts.
Did he clean the screen and the hoses?

The throttle body plate adjustment (totally shut ) may be off in relation to the switch just clicking to tell the computer to come off idle mode. It will then move the timing and fuel enrichment pulses for more power.
This setup gets out of adjustment faster by a human in most cases trying to fix an idle problem.

There is descriptions in manuals to set the plate correctly but use the stop screw only as a stop. Not to make it idle higher. You only give it a turn upwards after contact of maybe 1/8 turn!
The plate must remain close to keep the IAC in its control range.

You might want to cleaned the bore of the throttle body with a rag soak with carburetor cleaner and one finger anyway. This way you don’t get cleaner into the throttle switch.
Make sure no air gap exists.
Inspect the snorkel/accordion hose for any pin holes or cracks in the volutes. I use a fluorescent light tube down the center that throws light outwardly at 90 degrees. Wiggle the hose a bit to expose any fissures. Make sure the clamps are tight and seal well behind the AMM.

Does it also hesitate to start or drift idle speed only when it’s the coldest or only after the car has set overnight or several hours?
Does it do ok the rest of the day after warmeded up? This is comparing a cold lean mixture versus warm lean mixture.
IMHO it is “Similar” to a ECT complaint from two directions but you are touching the pedal so the problem is connected to the exact moment of pedal movement!

Down the road, this might evolve into another issue dealing with a FPR performance over a FPR leakage, the in-tank pump or the level of fuel in the gas tank.

Just pay attention to the different times of day. Observe the suddle differences and the car will talk to you with some clues.
One is:
Like it’s running fine and then twice a minute or so, the idle bumps up and back down. That’s usually a plug miss firing. The computer quickly tries to cover it up! It’s fast and sensitive, called “self tuning.”
The IAC unit is working fine!

@129,000 that cars engine wear is just barely past broken in! In other cars that’s over @ 25,000.
IHMO (:)

Phil

For a non-turbo:

Sounds like a temperature sensor or wiring issue:

Check the wires and the connection at the 2 wire water temp sensor for the fuel injection. Corrosion can build up on the connections. See If jiggling the connector makes a difference.

Unfortunately, the water temp sensor is under the intake manifold and isn't easy to access. FYI, the 1 wire sensor for the water temp gauge is under there too.

You might have to remove the connector and those aren't easy as the wire retaining clip is hard to remove even when access is good. You can sometimes jiggle the connector off by rocking it side to side.

You can practice on a fuel injector connector, but be careful as you can break the connector. New updated connectors are available.
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com