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95 Blazer rough idle


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gscrippler's Avatar
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June 9th, 2009, 6:59 PM   #1  
95 Blazer rough idle

Hey guys,
I'm new to this forum have been trying to solve a rough idle issue for some time here is a list of things that have been done hopefully someone can help me, I've posted on another forum with some help but here is my summary
I replaced my spider injector unit today
, But the new unit did not solve my Po301 problem misfire cylinder #1 symptom is (Rough Idle) Here is a list of all the stuff I have done to try and resolve this issue. If there is something You think I might have missed please let me know.
Components changed
High Voltage ignition switch (distributor) includes new cap & rotor
Coil, Plugs, Wires.
Throttle Position sensor, Idle Air Control sensor, O2 sensors, Egr Valve with screened gasket, Coolant Temp sensor. Checked Voltage at each connector as well all are at recommended voltages
within the last 2 months have replaced the Muffler and Cat Converter
New Muffler, Cat Converter
conducted a compression check on cylinder #1 compared to cylinder #5 both the same
while truck was running i applied pressure in each direction to see if a valve guide was worn but no results,

Components I have not changed
MAP sensor
Ignition control Module. From what I understand this either works or doesn't work found some post one other sites where it could possible cause my symptom
I'm kind of ready to throw in the towel Only thing I haven't done yet is a cylinder leak down test. If you have any suggestions please give them to me
Thanks

 
suzuki-guy's Avatar
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June 9th, 2009, 11:09 PM   #2  
Have you tried Vacuum lines? What is your fuel pressure? Fuel filter? Try running sea foam through it.

 
gscrippler's Avatar
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June 10th, 2009, 5:46 AM   #3  
Ran all new vacuum lines seafoamed it and fue pressure holds at 60lbs not running 57lbs running, was wondering if a tired ICM might be the culprit
No stalling issues infact the truck runs better than ever with all the component replacements i've done except at idle, any other suggestions would be great
Thanks

 
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June 10th, 2009, 6:44 PM   #4  
Ignition control module usually just goes out. Try tapping it with a screwdirver well its running and see if it sputters but I would not think that this would be the culprit. Did you try fuel filter? Whats your compression run all around?

 
gscrippler's Avatar
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June 11th, 2009, 7:33 AM   #5  
Changed the Fuel filter about a month ago, the fram one I had in it completely
failed inside was like a rattle but will put another one on. I did a compression test on cylinder #1 and #5 for comparison it was just a little over 120lbs

 
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June 11th, 2009, 5:52 PM   #6  
Thats pretty low! You Should test all of them!

 
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June 11th, 2009, 8:37 PM   #7  
When you changed the TPS did you test the voltage and adjust the idle and wide open throttle signal?

 
gscrippler's Avatar
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June 11th, 2009, 10:57 PM   #8  
Posted By: mudmaniac When you changed the TPS did you test the voltage and adjust the idle and wide open throttle signal?
Yes I had it hooked up to a tech 2 scanner and closed throttle and WOT were within the specified voltages, I'm gonna replace the IAC, MAP, and ICM
and if that does not solve it gonna have to consult the pro's on this one
Spent today looking for vacuum leaks and gasket leakes but no luck!!

 
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June 12th, 2009, 5:22 PM   #9  
There is a way to test the mapsensor! Do you have a Haynes manual? Mudmaniac how do adjust TPS? I don't think I did that when I replaced mine?

 
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June 12th, 2009, 9:58 PM   #10  
i don't think you can adjust a TPS but if you know how to test the Map sensor please let me know I have the 3 GM manuals for my 95 but didn't see anything

 
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