1997 Chevy Blazer Major vaccum leak

HPI555

MEMBER
1997 CHEVROLET BLAZER
6 CYL
4WD
AUTOMATIC
138,700 MILES

I have a chevy blazer with a fully rebuilt v6 in it with only 8000 miles on itand ran fine for a while with no problems at all and it has had random cylender missfire ever since the weather got colder. All my ignition parts are ok they are not causing the problem at all. My mechanic said that I have a vaccum leak so he retorqued my intake maifold and it helped a little bit but he still says that I have a vaccum leaks somewhere. Ho do I know for sure that I can automaticly rule out the intake manifold gaskets because like I said they are not that old. This engine missfire is really bad when its cold but gets a tad better when its warm sometimes the engine dosnt do it at all. And also to nothing is leaking or reqireing any fliuds at all. Thank you!
.

2 Replies

DOCFIXIT

MECHANIC
18,828 POSTS

Check zEGR operation if not seating can cause a lean miss fire. Also take carb cleaner spray around intake and throttle. If vac. Leak engine will stablize or speed up when cleaner is sucked into leak.

SPONSORED LINKS

Was this

answer

helpful?

Yes

No

Tuesday, February 10th, 2009 AT 9:57 AM

HPI555

MEMBER
11 POSTS

Hi I know that it has been a while but the problem is still occuring havent checked the EGR operation because from what im told it can only be tested from a computer and also I dont see a vaccum port on it either because its electronically controlled. But anyways it seems to missfire wheather the engine is cold or hot and also to it dosnt missfire sometimes at all no matter how cold or hot the engine is. I have come to the concusion that it might be my engines sensors but no troble codes come up besides the po300 code which is oviesley the random cylinder missfire. But I dont know im stumped on this one I think that it might be time to take it to a really good shop! Any ideas on this one thank you!

Was this

answer

helpful?

Yes

No

Sunday, March 8th, 2009 AT 8:36 PM