CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

2005 Chevrolet Blazer - Idle issues

Blazer hasn’t been idling right, the check engine light comes on sometimes and the check gauge light. Today I stopped at store and when I went restart it, it would turn over but when I give it gas it stops crankin

Very important question . . .

Do you in fact have a 2005 Chevy Trailblazer with the 4.2 liter inline 6 cylinder . . . ?!

here’s the reason I’m asking . . . The Chevy Blazer is a completely different truck, almost nothing in common with the TrailBlazer

Not only that, but I don’t believe there was a 2005 model year Chevy Blazer, but there was definitely a 2005 model year Chevy TrailBlazer

And the advice might be different, based on which truck you have

This means that a Diagnostic Trouble Code has been recorded by the vehicle’s OBD system.
Until you have the stored trouble code(s) “read”, nobody could possibly give you an answer with much value. Most auto parts stores (Autozone, Advance Auto, O’Reilly, possibly others) will do this–gratis. Then, you can come back to this thread to report the exact code(s) which will be in a format similar to P0123.

… and then there is this issue:

Yes it is a blazer 4x4 v6. Thanks.

Retrieve trouble codes . . . a cheapo OBD2 code reader should suffice for this

slow cycle the key from off to on a few times before attempting to start the engine

If this gets it to start, there might be a fuel pressure/delivery problem

As for “hasn’t been idling right” . . . has the check engine light been flashing while this is going on?

There are several possibilities for the “check gauge” warning light to remain on at idle, such as incorrect voltage, low coolant level, overheating, and so forth. Does any of this ring a bell?

A dirty throttle body could be part of the reason for the rough idling. I certainly don’t think it’ll solve all of your problems, but it’s cheap and you really can’t do any harm.

You should also consider checking your battery connections. Since you seem to have a Blazer with the 4.3 liter V6, you have a battery with side terminal bolts. First of all, grab the cables. If you can turn them counterclockwise, the connections aren’t tight and you need to fix that. If they are tight remove the bolts . . . negative first . . . and check everything out. You’re better off removing the bolt from the cable itself with a pair of pliers. Don’t be surprised if the bolt has stripped threads or you see a lot of corrosion. Clean off any corrosion with a baking soda/water solution and a brush. All automotive parts stores carry the side terminal battery bolts for General Motors vehicles. They’re cheap.

Hello, i got in my blazer nd it started right up. I drove about 10 miles home and parked it. When i went to drive it a few hrs later it wouldnt start again. Ive changed the dist. Cap twice in the past 3 or 4 months. I tried to spray starter fluid in the throttle body but still wont start. Also the check engine light is no longer on. Any suggestions would be appreciated.

I suggest the next step is using a spark tester

With the ignition off, undo one of the spark plug wires from a spark plug . . . whichever one is easiest to get at . . . insert the tool instead of the spark plug. Clip the tool to a good ground. Crank the engine over. you should see an extremely bright blue spark

I’m aware the engine won’t start

That said . . . has it ever stalled on you while driving?

3 Likes

Yes it has stalled. Sometimes it runs great with no problems. Other times i got to hold the brake and gas at the same time when at a stop sign to keep it running. Thanks again for taking the time to help.

It is really important that you retrieve the CEL code and post it here, otherwise everything else is a guess. Could be as simple as a super dirty air filter or IAC valve. Even if the CEL turns on and off, there is very likely a pending code stored. Autozone or Advanced Auto Parts will retrieve the codes free.

1 Like

When does it stall?

At a stop light . . . ?!

Cruising at 35mph . . . ?!

I agree with @kurtwm1 . . . please provide us with the stored trouble codes. And he’s right about the iac valve. That could cause stalling in certain conditions

Hello, yes it sometimes stalls at stop lights and sometimes lately driving it i can feel just a little hesitation. But anyway i went and looked to see if any codes read but it said no faulty codes… Im surprised because the check engine light is on. I tried to start it again and still nothing. If it were the IAC valve good bad would that cause it not to start at all?

So there obviously weren’t any current codes

But were you able to check for history/stored or pending codes?

You might need a different and/or better code reader or scanner

Now that it’s not starting, check for spark, using that tool I showed you

You should also hook up a fuel pressure tester to the test port key on engine off. You might have to cycle the key a few times to get the highest reading.

A bad iac can make it extremely difficult for an engine to start and stay running . . . and they don’t always result in a fault code. And it it can result in quite a few of the symptoms you’ve described

1 Like

If the check engine light is on there will be fault code(s). Where did you go to have the codes retrieved?

1 Like