OBD code 33, 91 pontiac grand prix

20

Asked by Feb 20, 2017 at 06:13 PM about the 1991 Pontiac Grand Prix 4 Dr LE Sedan

Question type: Maintenance & Repair

91 Pontiac grand prix 93k miles, upon start
up  it idles normal, then idles pretty high and
check engine line comes on and then engine
starts to surge, always dies at idle, there is
hesitation in accelerating and decelerating
plus after driving a bit on the road the check
engine light eventually goes away but once I
let off the gas it comes back on, brand new
map sensor and iacv, still won't run right
pleas help.

2 Answers

79,265

Check for vacuum leaks. Use some starting fluid or carb cleaner and spray along the intake manifold gasket, and around the throttle body base gasket. If there is a leak the rpms of the engine will pick up. Do this on a cool engine where the rpms are at idle.

Best Answer Mark helpful
5,695

If you are still diagnosing, try replacing the ECM. I had the same symptoms (and a few others), did all the normal "tune up" stuff and finally fixed it by replacing the ECM. MY car was a 5L '91 Trans Am and it was NOT throwing any codes when the computer part broke down. Good luck.

Your Answer

Pontiac Grand Prix Experts

  • #1
    Js08016
    Reputation
    4,590
  • #2
    Tom Demyan
    Reputation
    3,170
  • #3
    munron
    Reputation
    2,600
View All

Related Models For Sale

Used Pontiac Bonneville
397 listings starting at $1,995
Used Pontiac Grand Am
931 listings starting at $2,295
Used Ford Mustang
342 Great Deals out of 41,799 listings starting at $1,488
Used Chevrolet Camaro
371 Great Deals out of 31,504 listings starting at $3,000
Used Pontiac Firebird
5 Great Deals out of 694 listings starting at $3,911

Used Cars For Sale

2008 Pontiac Grand Prix For Sale
7 Great Deals out of 368 listings starting at $1,900
2007 Pontiac Grand Prix For Sale
311 listings starting at $4,499
2006 Pontiac Grand Prix For Sale
413 listings starting at $4,000
2005 Pontiac Grand Prix For Sale
306 listings starting at $2,499

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.