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

75,545

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
5,345

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
    4,460
  • #2
    Tom Demyan
    Reputation
    3,070
  • #3
    munron
    Reputation
    2,490
View All

Related Models For Sale

Used Chevrolet Camaro
862 listings starting at $12,000
Used Ford Mustang
10 Great Deals out of 1,078 listings starting at $4,500
Used Pontiac Firebird
17 listings starting at $8,700
Used Nissan Maxima
40 Great Deals out of 375 listings starting at $2,985

Used Cars For Sale

2008 Pontiac Grand Prix For Sale
5 Great Deals out of 23 listings starting at $1,999
2007 Pontiac Grand Prix For Sale
6 listings starting at $4,990
2006 Pontiac Grand Prix For Sale
15 listings starting at $5,995

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.