Well, I’ve had it apart several times checking everything. It all started one day when the howling began. Replaced the oil separator. Howling gone. But, the loping idle and stall remains. Checked every possible vacuum leak. Replaced the o-ring to the brake vacuum. Checked for cracks in the intake. None. Even checked the camshaft solenoid. All electrical connections are good.

Done a pile of research. Fuel pressure sensors. Bad coil packs. Vacuum leaks. MAF units.

if there are any wrenchers out there that can help me solve this. I’m at a loss.

been driving Volvos since 1974. Been through all the models from the 120 on. This new one to me make me learn all over again. Wish I still had my ‘98 V70 turbo.

*2005 V50 2.4i FWD*
*2000 V70XC*
*1998 V70 AWD*
*1996 850 wagon*
*1990 245 GL* (x2)
*1980 242*
*1980 245 GL*
*1976 265 GL*
*1973 145 GL*
*1969 144 2.1*
*1968 142 2.1*
*1966 122*
*1966 125*

 

What does your VIDA or appropriate scan tool tell you? Any codes? Live data? Fuel trim values?

You might need to just erase what's there and let the control units figure out what mixture is needed for the engine to run properly.

 

The only codes that show up after the stall are P0100.

 

Ok. Another test run. Still getting a whirring noise. Almost as if it was a vacuum leak. Stumbles at idle. Recovers. Stumbles again. And dies. Where could I possibly have a vacuum leak?
double checked the line on the lower connection behind the MAF. All tight. Even the lines leading from the small control unit it plugs into are fine. Breather box to MAF has no cracks or splits. PCV system is intact and clear. Brake boost like are intact.

Yet, there is still that unmistakable sound.

 

[QUOTE=57gretsch;492554]Almost as if it was a vacuum leak. [QUOTE]

Spray carb cleaner in around the intake area - if there's an air leak the carb cleaner will make the engine run differently - I've heard you should not use brake cleaner for that purpose - something about poison gas created when a chlorinated brake cleaner burns.

 

brake cleaners are typically carbon tetrachloride based (ie like dry cleaner fluid) which is not flamable - but as noted can be decomposed into phosgene (highly toxic, ie what was in a WWI gas attack) and hydrogen chloride... Carb cleaner is the way to go :-)

 

Volvo suggests - bad connection, air leaks, bad MAF

These guys have some diagnostic ideas, have not heard the barometric pressure comparison before

https://repairpal.com/obd-ii-code-p0100

 

The P0100 suggests the ECU is not getting a correct signal from the MAF. I'd start by checking out the connector and wiring, then clean the connector and the contacts to the MAF and see if anything changes. You can also try starting up the car and unplugging the MAF to see how it changes the idle (if at all)