1998 v70 NA running rich

[ghansenv70]

Picked up the car back in June of 23. Since then it like to breakdown on me and has always run rich since I bought it so far I’ve replace the maf, fuel pressure regulator.( the one next to the main fuel filter) pcv but it is developed a leak again. Cleaned and regapped the plugs, clutch master cylinder and ran a fuel system cleaner from liqumolly when I first bought it. I’m debating on running a can of injector cleaner though it to see if it helps. It’s been running rich since I bought it and it’s very noticeable from the smell alone. I also have developed a new issue that the dash flickers at idle and will dip to about 300 rpm and almost die every so often at random it will also almost stall when I turn the heat on full blast at idle. I have been feeding it ps fluid due to a leak in the system and have spilled a good amount of fluid on the alternator over time but the car will run with the battery disconnected. I’ve been fighting this car for a while in trying to get it run smoothly and reliably so any help is appreciated I’m mainly focused on it running rich at the moment but any ideas on both issues would be greatly appreciated thank you

[Clemens]

Possibly a vacuum leak somewhere? After a decade of running too rich, my indie finally fixed that rich running Opel my granny used to drive because he found a kinked hose.
Also, try to unhook the MAF' electrical connector. If you replaced it with something that was non Volvo 850 specific or of cheap quality, you might get better results without the MAF.

[scot850]

For your rough running issue, it could be the MAF is bad, the throttle body is dirty or even a bad battery/alternator/battery cable/ground issue. Most of your large parts suppliers like AutoZone carry electrical system testers that may give you a clue to the charging and battery condition to eliminate those. If the battery cables are the originals and in your part of the world, they may be corroding inside.

Neil.

[misha]

..."but the car will run with the battery disconnected..."


You don't do that on ecu equipped cars.
Something is allready fried in that car...ecu,alt,relay,sensor(s)...etc.

[scot850]

+1 on not running the car without a battery.

However, there are several other things that can cause issues of rich running on these cars:

1) ECT - Coolant temp sensor not registering temp correctly. There is a resistance value that can be measured relative to ambient to check this. Also check the wires to the connector on mounted on the rear of the power steering pump as well as the connector itself. If this is out of spec it will cause poor starting and rich running.
2) As suggested, check the hoses in the engine bay for leaks and splits. At least being an NA it is a little easier. Check the little hose which I think the 98 NA has on the end of the intake at Cylinder 1 end. That likes to spilt or fall off on the elbow connector.
3) Check the PCV system for pressure build up. Rubber/latex glove held with elastic bands over the oil filler. If it inflates at idle or on revving then your system is needing cleaned. I seem to recall the 98 still have the flame trap near the throttle body which blocks up.
4) What MAF are you using. Off brands may work but Bosch is best if you can find them. I think Bosch has stopped making them, but Volvo still has a stock at stupid prices.
5) O2 sensors. When were they last changed?
6) I know you ran cleaners through the engine, but have you actually cleaned the throttle body?
7) What plugs are you using? Are they gapped to 0.028?
When were was the ignition system last serviced? Distributor cap, rotor, wires?

Neil.