[rosso75]

Yeah, I know....lots of threads on black smoke.

I have a '94 850 turbo, OBD2, with unknown mileage (engine replaced by previous owner). When I got it, the car was blowing black smoke and running like crap. I have a little experience with this problem, and found the hose between the oil seperator and the turbo was cracked and broken into a dozen pieces. I put a new one in and the problem was solved.

A week ago I loaned the car to a friend who said he was driving down the road and it started smoking and losing power. He limped it back, and it's running just like it did when I bought it. I checked all the hoses, and the air filter & intake tube for an obstruction. Nothing. It's obviously running very rich though.

My plugs (Bosch Platinum), rotor, and cap have about 5k on them. I pulled the plugs and they were all completely fouled black. I cleaned them, put them back in, and the car ran better for about a mile. The strange part is that I have no codes. I've checked twice.

So, like I said - lots of threads on black smoke. In most cases though it's an air hose that's come off, or somebody has a code to point in a particular direction. I've got neither.

Any thoughts appreciated.

[rosso75]

Hey....
I obviously got this in the wrong category somehow. Can a mod move it for me please?
thanks

[Young Burnsy]

Well it's generally understood here that using platinums or any multi tip plugs in these cars is a bad idea. So do your self a favor and get some new coppers or OEM plugs.

As far as the black smoke issue since it's not consistent it would probably best for you to start with a stage 0.

[rosso75]

I've always put Bosch platinum's in everything I've owned, which has been pretty much all european. I've never had a problem with them, though I've heard about it, and actually seen it once on a Ford 2.3 Mustang. I figured with all the other Bosch electronics in there, it should run good with their plugs too. I'll give it a shot though.

Swapped the MAF from my other '94. No change.

[TorqueSteer]

Young Burnsy, on 02 July 2009 - 10:07 PM, said:

Well it's generally understood here that using platinums or any multi tip plugs in these cars is a bad idea. So do your self a favor and get some new coppers or OEM plugs.

As far as the black smoke issue since it's not consistent it would probably best for you to start with a stage 0.

Not true. When my car was stock, I ran Bosch Platinum 4 tip plugs for 2 years without any problems, and with great performance for a stock car. I switched to copper only when I began to mod the car and increase boost.

[shellshock]

Fuel pressure regulator. I'm positive of it. Remove the little vacuum line and see if you smell gas in it. My buddys 850T was running rich and blowing black smoke and this was the problem. Easy 10 minute fix

[erikv11]

shellshock, on 03 July 2009 - 02:04 AM, said:

Fuel pressure regulator. I'm positive of it. Remove the little vacuum line and see if you smell gas in it. My buddys 850T was running rich and blowing black smoke and this was the problem. Easy 10 minute fix

hey I'm curious can someone clarify - which little vacuum line (pic maybe?)?
is he supposed to smell gas, or not supposed to?

[randomdude]

when my car was blowing black smoke, and losing power, it was because i had a hole the size of a quarter in my intercooler hose where the IAC hose meets it. no codes were thrown.

[rosso75]

Quote

which little vacuum line (pic maybe?)?

On the fuel pressure regulator there is a hose where the fuel enters on one side, and a vacuum hose on the other side. The vacuum hose runs to a fitting on the manifold and an increase in vacuum increases fuel pressure. If fuel is getting by the diapharam inside it will get sucked through the vacuum hose, into the intake, and run rich. I'll try and attach a pic.

I hadn't thought of it, since the pressure regulator is new, but checked it anyway. No fuel smell.

Hmmm....hit the wrong button. Lets try this....

Attached File(s)

•  PresReg.JPG (523.41K)
  Number of downloads: 12

[rosso75]

Found it. I got a hole about the size of a quarter on the top side of the lower innercooler hose. I didn't quite get my fingers all the way around it when I was under the car checking the first time.

I had a friend once who used to say "You can't tell for sure until you've checked it at least 3 times." I found it on the second check. Thanks for the suggestions.

[erikv11]

rosso75, on 03 July 2009 - 12:29 PM, said:

On the fuel pressure regulator there is a hose where the fuel enters on one side, and a vacuum hose on the other side. The vacuum hose runs to a fitting on the manifold and an increase in vacuum increases fuel pressure. If fuel is getting by the diapharam inside it will get sucked through the vacuum hose, into the intake, and run rich.

OK well when I shut off the car then pull the vacuum line to the FPR, there is a faint whiff of fuel from the vacuum line. Checked it several times the last few days, always the same, no doubt about it there is some gas in that line.

Maybe this explains the crappy mileage I've been getting for like a year. But no codes for rich, no black smoke except after long period of idling which I think may be valve stem seals, PCV recently done.

I'm going to replace the fuel pressure regulator, it is either original or has minimum 90k on it since I bought the car.