Compression issues & black smoke on start up

Asked by Jul 15, 2016 at 11:27 PM about the 1992 Pontiac Grand Prix

Question type: Maintenance & Repair

Ok I just had my 92 grand prix 3.1 engine
rebuilt. But...it's not running right! It's a long
story so stay with me. First it sounded like a
drag racer when it got started. Then a
cylinder had bad compression that suddenly
turned to good compression (40psi-150psi).
Also had a faulty fuel injector dumping too
much fuel. So I got new fuel injectors & got a
valve adjustment. The car sounds better but
can still hear a light pinging noise plus I saw
black smoke on start up. Now the
compression issue has returned. First it's
bad...now it's good again. Oh yeah it's not
the same cylinder doing it either. First it was
#5 then #1. Why would compression
fluctuate? Why am I still using too much
fuel? If the engine was properly rebuilt why
are these issues accruing? Obviously it
wasn't properly done. Lol. But I want my car
repaired & selling is not a option! Anyone
have a idea on what's wrong? Really
confused about the compression.....

2 Answers

20

The timing chain might not be timed correctly

3,945

If the rebuilder also installed it in your car, then I think its their problem, not yours. Drop the car off at their shop and tell them to call you when its running right. If someone else installed it then its more complicated. It could be any number of electronic or tuning issues totally unrelated to the rebuild. The engine itself might be fine, although the fluctuating compression seems suspicious. It will be up to the installer to pinpoint the problem and then you can decide how to address it. Putting a new engine in an old car is never a good idea. Hopefully the lesson you are learning won't become too much more expensive than it already has.

Your Answer

Add photo

Related Questions

  • Compression issues & black smoke on start up 2 answers

    Ok I just had my 92 grand prix 3.1 engine rebuilt. But...it's not running right! It's a long story so stay with me. First it sounded like a drag racer when it got started. Then a cylinder had bad ...

    1992 Pontiac Grand Prix

    -

    Maintenance & Repair

  • cooling issues, fans wont start 8 answers

    98 grand prix,3.8,. had a blown head gasket, removed the heads had a valve job done, and replaced all gaskets involved with replacing the heads. also replaced radiator, water pump, tstat, ect sensor, ...

    Pontiac Grand Prix

    -

    Maintenance & Repair

  • Smoke from exhaust pipe 1 answer

    Just bought a 2008 pontiac grand prix v6 247k miles it drives really great due to the miles havent had any major problems ... Just concerned about the smoke that comes out my tail pipe .. When in ...

    2008 Pontiac Grand Prix Base

    -

    Maintenance & Repair

  • any suggestions on rust issues on a 2002 pontiac grand prix gt for future references?, trunk? fuel door?, rockers? door & fenders meet 5 answers

    any suggestions on rust issues on a 2002 pontiac grand prix gt for future references?, trunk? fuel door?, rockers? door & fenders meet

    2002 Pontiac Grand Prix GT Coupe

    -

    Maintenance & Repair

  • Thermostat issues 1 answer

    Temperature gauge goes up and down when driving doesn't get close to overheating but drops all the way down and heater stops blowing cold air doesn't happen when running idle what can be issue

    2005 Pontiac Grand Prix Base

    -

    Maintenance & Repair

Search Pontiac Grand Prix Questions

Pontiac Grand Prix Experts

#1 Js08016
Js08016
Reputation 4,270
#2 Tom Demyan
Tom Demyan
Reputation 2,870
#3 munron
munron
Reputation 2,210
View All

Related Models For Sale

Used Pontiac Bonneville
4 Great Deals out of 511 listings starting at $1,799
Used Pontiac Grand Am
1,183 listings starting at $1,599
Used Ford Mustang
543 Great Deals out of 45,845 listings starting at $1,999
Used Chevrolet Camaro
244 Great Deals out of 31,194 listings starting at $369
Used Honda Accord
948 Great Deals out of 77,739 listings starting at $899
Used Pontiac Firebird
4 Great Deals out of 768 listings starting at $1,791
Used Nissan Maxima
324 Great Deals out of 24,382 listings starting at $999
Used Nissan Altima
1,154 Great Deals out of 79,676 listings starting at $500

Used Cars For Sale

2008 Pontiac Grand Prix For Sale
18 Great Deals out of 431 listings starting at $1,995
2007 Pontiac Grand Prix For Sale
3 Great Deals out of 397 listings starting at $4,299
2006 Pontiac Grand Prix For Sale
6 Great Deals out of 462 listings starting at $1,600
2005 Pontiac Grand Prix For Sale
330 listings starting at $1,800

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.