Go Back   Blazer Forum - Chevy Blazer Forums > Mechanical & Maintenance > General Tech Help > 2nd Gen S-series (1995-2005) Tech
Sign in using an external account
Register Forgot Password?
Search


Welcome to Blazer Forum!
Welcome to Blazer Forum,

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to start new topics, reply to conversations, privately message other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join Blazer Forum today!


Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 05-14-2013, 11:57 AM
New Member
 
Join Date: May 2013
Posts: 3
BlazingChevy is on a distinguished road
Default 2000 Blazer 4.3VortecV6, rough cold start then purrs when warm

My 2000 Chevy Blazer 4.3 vortec V6 is messing with my brain. It runs like crap when started cold then evens out and is a rocket ship when warm. I've changed all sorts of sensors, fuel pump, rotor, cables, plugs, and lastly the spider injector assembly. Still does the same! I was thinking that maybe since it is related to temperature change that the thermostat could be stuck open and thus not allowing the motor to reach operational temps as it should therefore causing rough idle and stalls. I've searched the internet for answers and have found tons of people with the exact same problem but the solutions are always basic troubleshooting none sense. I'm through with the basis check wires crap. There must be someone out there with the plain and simple answer to a problem that has plagued so many Vortec 4.3 V6s. I read on the internet that GM had bad intake manifold seals and when cold fluid leaks into the cylinders and after warm the metals expand and seal it up again. Sounds logical but alot of work to just hope thats it. Please share your knowledge with me. I'm stumped. Thank you for your time.
Reply With Quote
  #2  
Old 05-14-2013, 02:14 PM
spittybays
Guest
 
Posts: n/a
Default

Help us out, what sensors have you changed?
Reply With Quote
  #3  
Old 05-23-2013, 10:05 AM
New Member
 
Join Date: May 2013
Posts: 3
BlazingChevy is on a distinguished road
Thumbs up UPDATE....Problem Solved.

So i took the truck in to a local auto shop. Diagnostics indicate code (P1345A /crankshaft/camshaft position sensors correlation) and (P1351A Ignition control system to high voltage) Had the ignition coil, electronic ignition module and crankshaft position sensor replaced. There was humidity getting into the ignition module and causing misfires on cylinders until the engine heat would remove the humidity. See... everything has a reason. Truck is strong again and runs great. Hope this was helpful.
Reply With Quote
  #4  
Old 05-26-2013, 12:00 PM
Starting Member
 
Join Date: Apr 2013
Location: South Carolina midlands
Posts: 193
jimspahr@msn.com is on a distinguished road
Default

Where is the Ignition Control Module found? How expensive is it? We appreciate you posting what the solution was. That is very helpful to the forum.
Reply With Quote
  #5  
Old 05-28-2013, 08:02 AM
New Member
 
Join Date: May 2013
Posts: 3
BlazingChevy is on a distinguished road
Default

Click the image to open in full size.Click the image to open in full size.
Its the electronic part to the right of the coil pack. It has two screws holding it in place. Not to expensive.Between 40 and 50 bucks.
Reply With Quote
  #6  
Old 05-29-2013, 07:48 AM
Starting Member
 
Join Date: Apr 2013
Location: South Carolina midlands
Posts: 193
jimspahr@msn.com is on a distinguished road
Default

Thanks for the good info and photo. Over the Memorial Day weekend, I bought the infamous Haynes manual and 'researched' the ignition module in the 'Engine Electrical' section. Not very helpful and actually confusing.
Reply With Quote
  #7  
Old 05-29-2013, 08:22 AM
Bodankie's Avatar
Beginning Member
 
Join Date: Oct 2012
Location: Raliegh
Posts: 12
Bodankie is on a distinguished road
BODANKIE
Default

Hey guys. I have the exact same problem. I just got my check engine light tested last night and it came up with the crankshaft position sensor. Any chance you can shed some light on how much it cost to replace? I normally like to make my own repairs but I heard this one is not an easy task. Thanks.
__________________
People like you are the reason people like me need medication
Reply With Quote
  #8  
Old 05-29-2013, 11:40 PM
Senior Member
 
Join Date: Jun 2010
Location: Graham, WA
Posts: 763
Toby Hanson will become famous soon enough
Toby Hanson polkaking
Default

I believe the crankshaft position sensor is not too difficult to replace. I think it's on the timing cover on the lower part of the block right in front. However, I'm also pretty certain that once it's replaced you have to take the truck to a dealer or a very well-equipped shop with a scan tool capable of doing a re-learn procedure.

If I'm wrong I would appreciate someone posting the correct information.
Reply With Quote
  #9  
Old 05-30-2013, 07:10 AM
Senior Member
 
Join Date: Oct 2008
Location: Tucson, Arizona
Posts: 766
LannyL81 is an unknown quantity at this point
Default

The crankshaft position sensor is attached with one screw and the electrical connector, loacted on the front cover. Access is simple, just remove skid plate if 4wd and it is on the right side. Very easy to replace.

HOWEVER....in order for the engine computer to make use of the new sensor the crankshaft position sensor relearn must be done which requires a high-end scan tool. Not the simple ones at Autozone or etc. Likely a dealership, but call around to find a shop that KNOWS what you are asking for.

You can replace the sensor yourself but until the relearn is done, the engine computer will use the stored information from the old one.

Let us know what happens.
__________________
LannyL81
2002 4dr 4wd S10 Blazer
Reply With Quote
  #10  
Old 05-31-2013, 12:27 PM
Starting Member
 
Join Date: May 2013
Posts: 117
phxjosh is on a distinguished road
Default

I have noticed my blazer runs a little rough when cold, but runs really well and quiet when warmed up. I am going to check my crankshaft position sensor as well, just need to find someone with a good scan tool.
__________________
1996 Chevy Blazer 2 Door 2WD
Reply With Quote
Old 05-31-2013, 12:27 PM
 
 
 
Reply

Tags
02, 2000, 43, bad, blazer, chevy, coil, cold, easy, hard, ignition, runs, start, starts, vortec, warm


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
rough cold start idle and rough running blazerguy22 2nd Gen S-series (1995-2005) Tech 10 11-14-2013 11:50 PM
1995 Blazer rough cold start rival904 2nd Gen S-series (1995-2005) Tech 11 01-14-2013 03:30 PM
'95 Blazer runs rough cold, great when warm cleburne red 2nd Gen S-series (1995-2005) Tech 11 02-21-2012 06:25 AM
2000 s10 blazer/trailblazer. hard to start cold netslinger727 2nd Gen S-series (1995-2005) Tech 7 12-30-2010 08:32 PM
2000 blazer cold start problem uncledenny 2nd Gen S-series (1995-2005) Tech 1 01-28-2010 05:36 AM

Advertising

Featured Sponsors
Vendor Directory
Our Sponsors

All times are GMT -5. The time now is 09:28 AM.

Internet Brands, Inc.