Ok this could be something simple. The car simply screams and does not miss a beat. Timming is set at 14 degrees, no pings. The smog pump has been removed by the previous owner so the cats that are on the car just blow out the back. I have black crap puffing out of my exhaust when I rev the motor. Its not gas, at least I don't think, it does not smell like gas. How can you lean out the motor if it is FI? Could the Cats be making this black crap come out the back? Im still learning with the FI, if it were a carb I could just set the mixture. Help me out guys.....

 

You can get an adjustable Fuel Pressure Regulator. I forgot how much they are offhand, but they aren't terribly expensive. It just pops in the rail and you adjust it with an alan wrench.

 

So you think thats my issue? But the exhaust don't smell like too much gas....... ill give your idea a shot

 

I thought you just wanted to know how to adjust the fuel pressure on an FI car. I would say the problem could be crap built up in the cats. I wouldn't know, they're the first thing I take off any car I buy.

Black is usually carbon or fuel, but you said it doesn't smell like fuel. How many miles are on the motor?

 

150k on the car, no clue about the motor, its too clean to be untouched since 87. I am assuming a rebuild since then. I plan on losing the cats tomorrow when I get my x pipe put on.

 

take off the h pipe, and get a metal rod and just bash out the cats.........


black smoke is usually carbon, oil burns grey, and smells a certain way, water is a misty white as well.........

lots of gas can be black, but the only true safe way to lean it out is to get a custom chip and tune, this will lean it out the whole powerband, adjustable FPR's are mainly for boosting the fuel pressure up (adding more gas) they dont work that well for leaning out the car......... most fpr's are only adjustable down to like 36-80 psi i believe, and stock sould be about 40psi, so theres not a lot of give when it comes to dropping the pressure down, and you want good pressure when your up as say 5k anyway........


its prolly something simple though, is the car throwing any codes?

 

haven't put a check on it, its speed density to boot, haven't found anyone with a scanner

 

well is the check engine light on? you can read the codes yourself with a paperclip, i think its the # 1 and #4 pin or somthing like that .........

do an internet search on pulling codes, there are alot of good sites on it

its really easy to do........

 

The first thing I would advise is to get it to a dyno and monitor air/fuel.Pending the outcome and if it is indeed a tip in rich condition you may consider the MAP sensor.The MAP on a speed density car is soo critical to driveability.If the map is good and A/F is still an issue believe it or not the condition of the motor can affect A/F due to the MAP relying on vacuum and or atmospheric pressure inputs to tune.That is in direct relation to the volumetric efficiency of the motor.The motor has to be healthy for speed density to run the vehicle 100%.Also check full sweep on the TPS,the vacuum source to be free of holes or cracks going to the MAP,and fuel pressure.The pressure w/ vacuum should be in the 30 to 34 range,w/o should be in the 34 to 40 range.Hope that was helpful.


James