85 244DL 161,000 miles.
I have very rich running condition and gas in the oil. I also had gas (liquid) discharge from the tail pipe (I am talking of the car).

What has been changed:
New gas tank (old one was FULL of rust and giving me hell for 4 years)
New pre-pump and sock
New main fuel filter
Used but good main pump and checkvalve is good 740Ti pump

I replaced all parts due to the prepump needing cleaning every 6months, and changing fuel filter every 6 months. Car was "bucking" like when prepump fails.
I pulled the fuel injectors and checked to see if they chad rust in them.
There was and is rust on the tops of the fuel injectors.

After reassembly the car starts and run SOOOO RICH that a trip to fill the new gas tank SMOKED the entire neighborhood out. I mean I had a smoke screen and I had to feather the gas just to limp home.

I have checked the FPR as per the 700 FAQs. I had a full stream of gas of the return side of the FPR.

After starting the engine I shut it off and cracked open the fuel rail at the FPR and NO SPRAY of pressure.

My question is could the injector/s be leaking that bad to cause gas to leak into the crankcase past the rings?

Or could the FPR be causing the problem even tough I have tried 3 different used ones.

Man I still love my Volvo but not driving her is killing me.

Please help!!!!!!

I will install a new FPR tomorrow and inspect the wiring harness. I strongly suspect the wiring is the problem. All the problems started when I removed the fuel rail and inspected the injectors. The wiring protective black jackets are hard and brittle. I know I need to replace the harness but I will attempt to repair it so I can drive the 240 to the salvage yard and search for a replacement harness. The wife hates it when I drive her 850 T5-R to the junk yard. Can you blame her.

Try replacing the FPR with a new one, check FPCGroton online, I just paid $37 for the one on my 89 740. And change the oil/filter while your at it.
Good Luck,
-Bob

This happened to me about 8 months ago, it was the fuel pressure regulator . Replace it and change the oil & filter for less than $50. Good luck Dan
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85 245 M46 194K, 92 245 A70 122K

Had the same exact condition. It didnt run very good and pure black out the tail pipe. It was the FPR. Got one local new for $65. Bendix part, not Bosch. Runs perfect now and 28mpg. Try a new one.

Mike
Tacoma

on another board I was told to check the temp sensor wiring.

Is the another possible cause?

I'd first check to see if the vacuum hose to the FPR is good. Pull off the vacuum hose and smell for gas. If there is gas there, the fpr is bad.

The engine temp sensor tells the computer if the engine is cold or hot. If it is always signalling that the engine is cold, the ECU will enrich the fuel mixture and you'll run very rich all the time. This may be your problem.