HI,

The MAF went tummy up on my 142k mile S60R. I'm the original owner.

The problem seems a bit odd, here's the sequence of events:

Starts then dies (costco parking lot)
Disconnect MAF
Starts and runs on default map - shows error on dash
Drive home and order new Bosch MAF from FCP Euro
Install new MAF
Starts then dies (error code on dash is gone)
Disconnect and runs on default map
Reconnect MAF
Starts and runs - now seems to be using default map
Disconnect battery 1 hour
Starts then dies
Disconnect and runs on default map
Reconnect MAF
Now runs, seems to be OK

HOWEVER, it now seems down on power. All that 'R' goodness seems to be gone. I heard that you have to do an ECU reload to complete the install. Does this mean a trip to the Volvo dealer? WOuld like to avoid that, but if I must, I must.

Let me know what you think, and thank you!

PS: Even after 140K+ miles, I still love the car. Volvo got this one right.

 

Any codes? Read and reset them and see what happens. A battery disconnect does not erase some stuff. (if it did that would be used to clear check engine lights so people could get an emission inspection)
ECU "reload" is not needed for a MAF replacement.

 

 

Erase and drive. See what codes come back. You have a fuel pressure fault - have you compared the real fuel pressure with live data? Fuel pressure sensors fail more often than an AMM. You have a low boost pressure fault also - there's your lack of power - (if the fuel mixture is correct)

 

OK, took a drive with the Torque app hooked up to the OBDII port. fuel pressure stayed around 44 pounds regardless of RPM or load. Engine bucked a couple of times when starting from a traffic light. Also revved to 4k in neutral and it died. Got some strong fuel smell. Restarted and revved to 5.5k no issue. Checked around the MAF for loose connections, vaccum hoses, etc. Nothing obvious.

A FP sensor is ~$50, I can grab one if need be, and have by next week.

Appreciate your insights!

 

What I meant was - connect a fuel pressure gauge and compare that to what the ECM thinks is happening.

You are missing that piece of info.

 

Yeah, I was hoping against hope the Torque app would be accurate. Off to buy a FP gauge. About time I got one anyway... It thinks it's making boost as well.

Edit: Noticed that the gas filter had not been changed in some time. Replaced that, and it might have helped a bit. Also, Harbor Freight was out of the Fuel pressure testing kit. Ordered online. Should be able to pick this up again this coming weekend (11/12/22)

 

OK, found the issue.

I could not get it out of my head that the car said it was making boost, but still was not running like it. So I took a look @ the intake system and found that the hose from the intercooler to the charge pipe popped off it's connection.

I reconnected the pipe, and what do you know, the car runs right again.

I still have the fuel pressure testing gauge kit and a fuel pressure sensor coming in, so will check that as well. But for now, it's looking good.

 

The FP Test kit came in this week and It came with a fitting that enabled me to connect it directly to the rail through the Schrader valve. Car showed 53 pounds FP at start up and then settled to 41 pounds through the rev range.




Car still stumbles on occasion, and the Torque app shows a P0193 'Fuel Rail Pressure Sensor Circuit High Input'. I have a spare fuel pressure sensor here I ordered just in case. Thoughts?

 

Update:

I installed the new Fuel Pressure sensor and WOW, what a difference. Engine runs strong and smooth now. I'm going to buy another one and have it in stock. It'll be the FIRST thing I check next time.

Car runs like new now, very happy. Hope this helps someone else.