Black smoke loss of power rpms jump all over

Asked by May 07, 2017 at 12:13 AM about the 2001 Pontiac Grand Prix GTP Coupe

Question type: Maintenance & Repair

I have a 2001 Pontiac grand Prix gtp
supercharged 3.8 liter v6 I have replaced the
IAC sensor tps sensor o2 sensors spark
plugs wires fuel filter and pump runs out of
gas at top of orange mark new mass air flow
sensor ecm new it still has the same
problem does anyone have the correct
answer of what exactly it is tired of wasting
money...Thanks

4 Answers

270

Check the cat and muffler

24,145

Check/test compression on all cylinders first and foremost to know if its worth any-more time/money. Running rich, fuel injectors may be dirty and to atomizing fuel any more.

1 people found this helpful.
299,135

I always diagnose before throwing parts at a vehicle. Is the Check engine light on? Scan for codes? Black smoke means running rich like engine creator mentioned. Is the car running on the cold side?

2 people found this helpful.
80,325

Definitely running rich. Fuel pressure regulator and/or fuel injectors leaking. These injectors are known for getting gumed up and becoming troublesome because of not spraying properly. Test the MAP sensor as well. A bad MAP sensor can make it go rich. What trouble codes do you have? With it running rich enough to produce black smoke, the service engine soon light has to be on! HTH. -Jim

Your Answer:

Grand Prix

Looking for a Used Grand Prix in your area?

CarGurus has 37 nationwide Grand Prix listings starting at $2,995.

Postal Code:

Pontiac Grand Prix Experts

  • #1
    Js08016
    Reputation
    4,740
  • #2
    Tom Demyan
    Reputation
    3,320
  • #3
    munron
    Reputation
    2,910
View All

Related Models For Sale

Used Chevrolet Impala
17 Great Deals out of 997 listings starting at $2,994
Used Chevrolet Monte Carlo
14 listings starting at $6,990
Used Pontiac Grand Am
21 listings
Used Chevrolet Malibu
46 Great Deals out of 1,980 listings starting at $2,390
Used Ford Mustang
28 Great Deals out of 1,228 listings starting at $5,995
Used Chevrolet Camaro
6 Great Deals out of 1,005 listings starting at $4,500
Used Pontiac Firebird
20 listings starting at $12,999
Used Nissan Altima
38 Great Deals out of 1,238 listings starting at $2,800
Used Honda Accord
29 Great Deals out of 1,638 listings starting at $1,500

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.