Engine dies when cold. Cold start injector? Anything special neede to replace?

Had same symptoms on my '90 740 Turbo Wagon as described by KP1 and Mike. The
fix was cleaning the Idle Air Controller (IAC), sometimes referred to as the
Air Slide. The car idle surged for a few miles after cleaning, but settled down
and is acting normal now (I'm assuming the cleaning agent worked it's way around
and finally allowed the internal mechanisms to "free up")

KP:

Before spending money replacing anything at all, I would take the time to clean the throttle body and IAC motor, set the idle speed to spec, and ensure that the TPS is adjusted to "click" when the throttle is closed.
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Mike W., '79 242GT (my project car), '85 245DL (son's project car), '87 245 DL (my daily driver), '90 244DL (son-in-law's daily driver), '91 744T (wife's daily driver), '94 944T (daughter's daily driver), Largo, FL

Mike,

I've done all you suggested to KP and the cold starting time has decreased significantly but the engine dies if I don't manually keep the throttle open to 1000+ rpm when starting cold. Additionally, just after it's started, I have to keep goosing the throttle because the computer(?) won't maintain the idle at 750 - when engine temp is not at operating temp. After nominal engine temp is reached, constant idle is maintained by the ECU, I think.

I haven't ruled out FP yet, but I do hear it energize on ignition key ON (more of a clunking instead of a whirl.) Once on the open road, no cutouts or engine sputtering - runs fairly smooth. It has pickuped a serious hesitation and bucking if I try to re-accelerate too rapidly from a stop or after a turn - a *smooth* acceleration does not cause the hesitation symptom.

Any thoughts?

---
Tommy Bray
1990 740 GL sedan

Tommy:

Lots of good information in the 700/900 FAQ. There are several more things I'd look at on your car. First, make sure you don't have a vacuum leak. Check all the hoses and fittings. Next, I think I'd pull the plugs and have a look. Sooty and/or wet fouled, or do they look normal? If they're sooty and/or wet, you might have a problem with excessive fuel pressure, caused by a bad fuel pressure regulator. KP's original suggestion, that the cold start injector was giving problems, may have some validity. Pull it (not that easy to get at), energize the fuel pump but don't turn over the engine, and see if the cold start injector leaks. Also, there could be a problem with the coolant temp sensor. There is a resistance test (covered in Haynes) that you can try if you have a multimeter. If you remove the sensor for this test, be prepared for some spillage of coolant. This is an LH 2.4 engine, is it not? Is the check engine light on? Any codes stored?
--
Mike W., '79 242GT (my project car), '85 245DL (son's project car), '87 245 DL (my daily driver), '90 244DL (son-in-law's daily driver), '91 744T (wife's daily driver), '94 944T (daughter's daily driver), Largo, FL

"...an LH 2.4 engine, is it not?"

If it's a non-turbo, then it's most likely a Rex-Regina system, not Bosch.

I bet a cold one on a failed or gummy idle air valve, sometimes called the "CIS motor" (constant idle speed). If the throttle body has not been serviced, then it's a good time to do this. If it has been serviced, then I'd double check that it AND the throttle switch are adjusted. A working and adjusted throttle switch, among other things, is critical to proper idle.
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Don Foster (near Cape Cod, MA)

Thanks Mike. I'll try all of the above. Looks like you're a seasoned Volvo vet.