SPONSORED LINKS

1997 Pontiac Grand Am misfiring

Tiny
WEBANGEL
  • MEMBER
  • 1997 PONTIAC GRAND AM
1997 Pontiac Grand Am 4 cyl 173000 miles

i have replaced the cam sensor, crank sensor, coil, timing chain plugs, tested fuel injectors, changed the plug boots and it still misfires 1 and 3 everything ive done it still misfires 1 and3
SPONSORED LINKS
Thursday, August 6th, 2009 AT 10:21 AM

7 Replies

Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
Hello, a misfire can be caused by just about anything. Did you visually check for spark at the plugs? Fuel pressure ok, use a gage?
Was this
answer
helpful?
Yes
No
Thursday, August 6th, 2009 AT 10:52 AM
Tiny
WEBANGEL
  • MEMBER
  • 5 POSTS
Yesi have visually checked spark have it 1 and 3 still misfieing
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Thursday, August 6th, 2009 AT 12:12 PM
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
What was the fuel pressure spec? Are the injectors pulsing?
Was this
answer
helpful?
Yes
No
Thursday, August 6th, 2009 AT 12:36 PM
Tiny
WEBANGEL
  • MEMBER
  • 5 POSTS
The fuel pressure was good and the injectors are pulsating could the lobes be worn or valves burnt how do I find out
Was this
answer
helpful?
Yes
No
Thursday, August 6th, 2009 AT 4:09 PM
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
You can't check proper fuel pressure without using a gage. Do a compression test on the cylinders.
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Friday, August 7th, 2009 AT 7:18 AM
Tiny
WEBANGEL
  • MEMBER
  • 5 POSTS
Compressioncheck is 180 lbs we did a leakage test and 1 and 3 misfires 2 and 4 has a 25% leakage
Was this
answer
helpful?
Yes
No
-1
Friday, August 7th, 2009 AT 1:24 PM
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
Maybe I misunderstood your post. To do a cylinder leak down test, the engine isn't running. The cylinder your checking, you bring the piston up to tdc compression stroke, pump in air through the spark plug hole, shut the air valve off, watch for a leak-down. Right now, I'm not sure why the misfire.
Was this
answer
helpful?
Yes
No
-1
Sunday, August 9th, 2009 AT 10:20 AM

Please login or register to post a reply.

Related Engine Misfire Content

Intermittent Misfire
VIDEO
Intermittent Misfire
Instructional repair video
Misfire Random Code P0300
GUIDE
Misfire Random Code P0300
The world of automotive diagnostics can be complex, with numerous codes and potential issues to keep track of. One of the more common engine diagnostic codes is P0300, which...
VIEW MORE

Sponsored links