Hi everyone, I just did a turbo on a 2000 Volvo S40 1.9. Quick backstory, a guy brought me the car because it was smoking like crazy and wanted the turbo replaced.

After the install, I experience a very hard start, Pressing the gas and opening up the tb helped to get it started. Once I got it to idle it would start up without much effort. It's currently running extremely rich is is misfiring in all cylinders.

I have spark, and have confirmed the turbo is working properly. All intercooler piping is connected properly and the vacuum lines are in the proper places. I replaced the vacuum switch as well.

Does anyone have any ideas on what else to check? Thank you.

 

Just got back from working on the car. The misfire goes away after about 2500 rpm and the engine doesn't misfire from there up. Changed the fuel pressure regulator to a known good one and saw no improvement. I have a spare maf sensor I can try as well. I let the car run at about 3000 rpm for a couple minutes and the turbo downpipe started glowing. Maybe, the car has a clogged cat? I'm gonna get under it tomorrow to see if it can be unbolted.

 

Sounds like it's lean. What do the plugs look like? Check the fuel pressure with a gauge? Any codes?

Oil smoke can toast an O2 sensor quick.

 

You can inspect the MAF and ICV as well the intake to look for general cleanliness. You can use MAF cleaner to clean out both. The ICV controls air at idle when cold so if it gums up can give a rough start. If you can pull the O2 sensor it should be a nice beige color not black - same with the plugs. A trick for checking for a plugged CAT is to pull the o2 sensor out to see if that changes the idle.

 

The plugs are as black as can be. It's definitely running rich. I'll swap the maf, and clean the icv. People are swearing up and down I should change the coil packs even though I have spark. We will see. I'll pull the O2 sensors and see what they're like too. I'm sure their fouled all to hell. Unplugging them, doesn't change idle, so its safe to say they're not giving the computer any info.

 

the idea of pulling the O2 sensor out of the downpipe before the cat is to let some of the back pressure out - if the cat is clogged. Good idea to unplug to see if its sending signal first...