1995 Blazer LS Sport rough idle
#1
1995 Blazer LS Sport rough idle
My blazer is running very rough at an idle. I started out that occasionally it would stahl out at a stop. Then it progressed to bucking a little bit when you let off the pedal and were coming to a stop ( like it was starving for gas). Now i have to push the gas pedal in order for it to start and keep the RPM's up for it to run correctly. At an idle it doesn't stay running. Not even a week ago i had a new transmission, fuel tank , fuel lines, and radiator installed to it. It has 104,000 miles on it. It sat for almost 1 year before i had this work done to it. Does anyone have any idea what it could be?
#2
RE: 1995 Blazer LS Sport rough idle
These symptoms sound like a clogged EGR. I would remove and clean the EGR valve first. Get a new gasket with an integrated screen on the supply side.
If that does not cure the problem, the next thing to do is check the fuel pressure.
If that does not cure the problem, the next thing to do is check the fuel pressure.
#3
RE: 1995 Blazer LS Sport rough idle
new fuel pump and sending unit as well
#4
RE: 1995 Blazer LS Sport rough idle
distributor cap & rotor.... Fixed mine with the same symptoms
corroded and worn leads in the cap, 75,000 miles
corroded and worn leads in the cap, 75,000 miles
#5
RE: 1995 Blazer LS Sport rough idle
Did your SES light come on with that. All that stuff is brand new aside from the egr:
New stuff:
Transmission
Fuel Tank
Fuel Pump
Fuel Filter
Sending Unit
Radiator
Plugs, Wires, Cap, and Rotor
It was stalling out at a stop before i sent it to the mechanic to have the above changed. I figured it was something to do with the fuel pump. Apparently i was wrong. I hope to find out today or tomorrow what the problem is. One guy i asked said throttle position sensor, another said fuel injector, and another said fuel injector lines so i guess i will wait and see what happens when i get the call from the mechanic. Thanks for all your help everyone.
New stuff:
Transmission
Fuel Tank
Fuel Pump
Fuel Filter
Sending Unit
Radiator
Plugs, Wires, Cap, and Rotor
It was stalling out at a stop before i sent it to the mechanic to have the above changed. I figured it was something to do with the fuel pump. Apparently i was wrong. I hope to find out today or tomorrow what the problem is. One guy i asked said throttle position sensor, another said fuel injector, and another said fuel injector lines so i guess i will wait and see what happens when i get the call from the mechanic. Thanks for all your help everyone.
#6
RE: 1995 Blazer LS Sport rough idle
wonder if they put a screened gasket on it-if there is possibly carbon it the pintle/valve??? Re-read all the above and didn't see where there is an SES lite on or not-this could certainly be a clue(if). As per Kyle....also-congrats on your recent promotion to Captain, Kyle! Don't know if you'll see this though...Jerry
#7
RE: 1995 Blazer LS Sport rough idle
Not sure what SES is, I don't have my book with me. I had my check engine lite on while running rough and when not starting. Cap & rotor can be expensive, if it does not look bad just clean the leads with sand paper.
#8
RE: 1995 Blazer LS Sport rough idle
Cap and rotor, expensive... I guess that is subjective. Since they have already been replaced in this case, I guess it really does not matter.
I do not recommend cleaning the contacts of the cap and rotor with sand paper though. It can cause spark scatter that could be worse than things being dirty.
Not sure if you were asking this, but SES == Service Engine Soon
As far as the OPs problem, are there any codes which would lead you in a particular direction? Have you considered what both JP and myself have already suggested? If not, what are you waiting for?
I do not recommend cleaning the contacts of the cap and rotor with sand paper though. It can cause spark scatter that could be worse than things being dirty.
Not sure if you were asking this, but SES == Service Engine Soon
As far as the OPs problem, are there any codes which would lead you in a particular direction? Have you considered what both JP and myself have already suggested? If not, what are you waiting for?
#9
RE: 1995 Blazer LS Sport rough idle
SES... of course, Yes it was on.
Cleaning OLD cap and rotor contacts is a temporary test not a permant fix. Since you have all new then that comment is void.
I'm not familiar with the 95, but if you have a mass air flow sensor try cleaning it or even making sure it is pluged in. Also make sure all vacuum lines are connected.
When you changed the plugs did you take notice of the ceramic color, and which cylinder each plug comes from.
Tan = correct fuel mixture
Dark = rich fuel mixture
White = lean fuel mixture
Do you smell gass or a rotten smell comming from the exhaust? = burning excess gass at the cat.
You mentioned stalling out at stopps, have you checked your TPS
A long shot would be to check your O2 sensor.
By far the best advice I could ever offer and I'm sure you know is to have a dealership diagnose your problem, theyare more familiar with their product thanyour typical mechanic. After they pinpoint the problem have them write it all up giving you all the parts info and costs, and pay for the diagnostic fee it's well worth it. Then take that list and do it yourself if you are capable, I do this all the time. If you have trusted local mechanic that you use, hopefully they will not just try and throw parts at it.
Cleaning OLD cap and rotor contacts is a temporary test not a permant fix. Since you have all new then that comment is void.
I'm not familiar with the 95, but if you have a mass air flow sensor try cleaning it or even making sure it is pluged in. Also make sure all vacuum lines are connected.
When you changed the plugs did you take notice of the ceramic color, and which cylinder each plug comes from.
Tan = correct fuel mixture
Dark = rich fuel mixture
White = lean fuel mixture
Do you smell gass or a rotten smell comming from the exhaust? = burning excess gass at the cat.
You mentioned stalling out at stopps, have you checked your TPS
A long shot would be to check your O2 sensor.
By far the best advice I could ever offer and I'm sure you know is to have a dealership diagnose your problem, theyare more familiar with their product thanyour typical mechanic. After they pinpoint the problem have them write it all up giving you all the parts info and costs, and pay for the diagnostic fee it's well worth it. Then take that list and do it yourself if you are capable, I do this all the time. If you have trusted local mechanic that you use, hopefully they will not just try and throw parts at it.
#10
RE: 1995 Blazer LS Sport rough idle
Mine was doing this last weekend and it was the pressure regulator leaking in the plentem.. I am supprised no one has suggested to take off the vortec sign and then take the 2 torx screws out of the air regulator (the little round black deal on the top) might have to turn it back and forth a bit to get it out. Anyways take it out and look in the hole and see if it is all shiny in there or if you see gas pooling up in there if you do that is your problem and the ses light would prob. be cyl misfire. That is the cheapest test cause you ain't out any money to start and it is a very common problem on these engines.