SPONSORED LINKS

2002 cmc with multiple misfire codes

Tiny
JDRUID
  • MEMBER
  • 2002 GMC SAVANA
  • 150 MILES
I have a 2002 GMC savana with a brand new gmc crate motor with less than 150 miles. It is throwing a multiple misfire code on cylinders 4&7. It was giving the same exact code before we replaced the engine. We have replaced the mass air flow, crank and all the o2 sensors. We were told we may need to reflash the computer we have taken to our local gmc garage and they said they could not find anything any suggestions
SPONSORED LINKS
Tuesday, September 13th, 2011 AT 2:55 PM

5 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
What about the injectors? Very important as the flow pattern may be off either giving too much or too little fuel in the cylinders.

Roy
Was this
answer
helpful?
Yes
No
Tuesday, September 13th, 2011 AT 5:46 PM
Tiny
JDRUID
  • MEMBER
  • 3 POSTS
Yes we have checked all the injectors and they are all fine. Distributor is fine, they spent 4 hours checking everything they could and still getting the same codes. It does not throw the codes when under load but as soon as we let off the gas the service engine light comes on with the multiple misfire codes
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Wednesday, September 14th, 2011 AT 12:39 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Are there any exhaust leaks?

Roy
Was this
answer
helpful?
Yes
No
Wednesday, September 14th, 2011 AT 12:59 AM
Tiny
JDRUID
  • MEMBER
  • 3 POSTS
No there are no exhaust leaks.
Was this
answer
helpful?
Yes
No
Wednesday, September 14th, 2011 AT 11:20 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Sounds like you have covered all the bases with the same results. You need help of a shop with a scanner to monitor whats happening with this system. It may be a bad pcm but needs to be confirmed before this expense.

Roy
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Wednesday, September 14th, 2011 AT 2:18 PM

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