1995 850 Turbo acting n/a and running rich

Kuhnboy · Post by **Kuhnboy** » 08 Sep 2019, 11:33

Ok. So I've been trying to figure this out for awhile. My car has been acting up all summer (I haven't been driving it because of it). It's been running very rich, and does not put the boost gauge past halfway. I've had a scanner on it to confirm the fuel issue other than the mpg gauge. I've checked intercooler hoses, wastegate rod, fuel pressure, and everything I can with obd2. I'm at a loss at this point, and any help would be greatly appreciated. Thank you in advance for any replies.

Post by **erikv11** » 08 Sep 2019, 12:47

You checked the induction hoses (good call) but did you also go over the vacuum lines carefully? Would have to be a big leak, maybe the fat brake booster hose?

Check carefully for vacuum leaks around the intake manifold while you are at it.

You can't check fuel pressure with obd2, if that's what you meant. Must use a pressure gauge. FPR vacuum line doesn't reek badly of fuel?

Does the exhaust flow freely?

Kuhnboy · Post by **Kuhnboy** » 08 Sep 2019, 13:06

I have actually replaced some vacuum lines from the tcv. I checked fuel pressure with a gauge off the rail, then with a scanner I mapped the short term fuel trim and the computer is dumping fuel into the motor. The exhaust does flow freely, the cat was replaced recently and I cut the pipe slightly after that and put a band clamp on it. It's currently disconnected so that's not an issue. And I have checked the FPR line, and no it does not smell like fuel.

Post by **abscate** » 08 Sep 2019, 13:51

Back to basics

Compression rotor plugs wires coil

If it’s misfiring the ECU will shut off boost, so get your engine running right first

Post by **erikv11** » 08 Sep 2019, 13:57

abscate wrote: ↑08 Sep 2019, 13:51 ... get your engine running right first

If that's not a given here, I'm in the wrong thread ...

Are there misfire codes???

Kuhnboy · Post by **Kuhnboy** » 08 Sep 2019, 14:04

I have tested resistance on plug wires, and all were in range. I did plugs 5k ish miles ago. It runs smooth, until I ask it to accelerate. There are no codes with it, and it doesn't sound like a misfire. Just sounds like it's hitting a rev limiter at 2k. I haven't had a compression gauge on it, but all cylinders sound even when cranking. I will take a look at the rotor. Any way I can test the coil other than getting a known good one?

Post by **abscate** » 08 Sep 2019, 14:16

Pull one plug and attach it to the wire, ground the thread, and look for a fat blue spark at the plug to confirm coil is good. Have a helper crank while you watch the plug under hood

Ohm measurements on plug wires aren’t too meaningful, most here swear by Bougicord and report problems with anything else,

greg850r · Post by **greg850r** » 08 Sep 2019, 14:21

abscate wrote: ↑08 Sep 2019, 13:51 Back to basics

Compression rotor plugs wires coil

If it’s misfiring the ECU will shut off boost, so get your engine running right first

This is how I would do it as well and I wouldn't trust a resistance test to rule out wires. If the plugs are not Volvo don't trust them either.
Take them out and read them. Do they all look the same? It would rule out a stuck open injector, but this does not sound like that is the problem. Bosch cap and rotor just because. Then I would look elsewhere.
If the computer is telling it to dump too much fuel possibilities (in order of probablility) are: Temp sensor in thermostat housing, front o2 sensor, MAF.

Kuhnboy · Post by **Kuhnboy** » 08 Sep 2019, 14:51

I do have bougicord plug wires. I have cleaned the maf, it read about 4.0 g/s and I also tried unplugging it. When I unplugged it the car just stalled. I do have a Bosch cap and rotor that are not corroded. I did replace both upstream and downstream o2 sensors with Bosch units. I'm still looking for my spark plug sockets so I can pull them out. I don't know if this is relevant to the temp sensor mentioned, but the fan kicks in when it should and my temp gauge reads right in the middle once the car warms up. The car did this when I first got it as well, but that was because the fuel line in the tank was loose and almost came off the pump. I already verified that isn't the problem again. It was fixed for a year, and then I was on an on ramp and I suddenly had no power. I apologize for adding things that I forgot, I've been working on replacing the motor in my pickup and that's taken priority in my mind so I'm remembering as I go with this.

Post by **BlackBart** » 08 Sep 2019, 15:17

It sounds a bit like a vacuum leak, or an intercooler component not being tight.