missfire#1 cyl.

365

Asked by Jun 14, 2011 at 01:34 AM about the 1992 Pontiac Grand Prix 2 Dr GT Coupe

Question type: Maintenance & Repair

92 grand prix 3.4l missfire #1 90psi all other cyl range 140-150psi i did a leak down and all cyl. were 10-15% even #1 no  indication of blown head gasket. pulled the head and looking at the valves in all cyl. they seam to be burning equal in all cyl.  pluges look good as well.pluges and wires are new fuel is not bad, no water or fuel in the oil. the cyl. has no scare or scrape either. pulled the piston and no broke or stuck rings. so why do I have a missfire and low compression on #1.  before you answer 1&4 share the same coil for ignition and #4 is fine. pluse no codes.

2 Answers

375

Well im gonna be honest. If you have the means to do so. Sell that car ASAP! That 3.4L LQ1 is a time bomb waiting to go off. either that or replace the engine with a 3.1. Head gaskets are alot cheaper than motors

365

thanks for the input. I finally pulled the head and come to find out the cylander is coned. which explanes bad compression but good leak down and excessive crankcase pressure.

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 Pontiac Bonneville
471 listings starting at $3,499
Used Pontiac Grand Am
1,027 listings
Used Chevrolet Camaro
456 Great Deals out of 31,180 listings starting at $3,550
Used Ford Mustang
557 Great Deals out of 36,486 listings starting at $1,500
Used Pontiac Firebird
11 Great Deals out of 761 listings starting at $2,500
Used Nissan Maxima
306 Great Deals out of 22,110 listings starting at $1,200

Used Cars For Sale

2008 Pontiac Grand Prix For Sale
6 Great Deals out of 389 listings starting at $1,750
2007 Pontiac Grand Prix For Sale
370 listings starting at $2,295
2006 Pontiac Grand Prix For Sale
3 Great Deals out of 415 listings starting at $4,850
2005 Pontiac Grand Prix For Sale
335 listings starting at $4,500

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.