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Discussion Starter · #21 ·

That connector is in the same harness as the coil connectors...right? I'm thinking that's the main disconnect for the coils. You could verify wire colors compared to the wires on the connectors that plug into the coils.

Forget "code readers". Codes can be helpful, but the real information is in the data stream. A REAL scan tool is needed.

Determine the misfire history (misfire counts) of each individual cylinder. This is not a "code", this is the number of misfires over time, per cylinder. "0" is a good number, anything more than one or two should get your attention. Hundreds or thousands is "bad news". When you know which is the problem cylinder(s), you can swap coils to see if the miss moves to another cylinder. If so, the coil is weak and getting worse. Could also be fuel injector, or an engine mechanical problem (burn valve, low compression, etc.) but my first guess is failing coil. When the engine is under load, the coil can't supply enough voltage to fire the plug reliably.
I saved my old coils and they worked fine before I swapped so I will rule them out by swapping with them.

Yes, that connector that im pointing to leads into the bundle of coil wires. Would a frayed wire in that harness potentially cause a short that would cause this to happen?
 

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2003 chevy trailblazer_ltz
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A frayed wire or intermittent ground could kill spark to one or more coils. But seems unlikely that this would only happen at idle, under load.

OTOH, you know that's a problem. Fix it, see what happens.
 

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Discussion Starter · #23 ·
A frayed wire or intermittent ground could kill spark to one or more coils. But seems unlikely that this would only happen at idle, under load.

OTOH, you know that's a problem. Fix it, see what happens.
I don't know how to go about doing that because i can't find the wires anywhere online
I could potentially cut out the torn up wire and splice it, but it's extremely close to the connector
 

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2004 chevy trailblazer_lt
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You could just use some stranded primary wire to splice into the torn up wire in order to repair it. I had to do that with a wire going into the neutral safety switch connector on our 99 Buick Century that a rodent chewed off right at the connector.
 

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2002 gmc envoy_slt
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I think That is the plug that runs power to the fuel injectors??...if it runs down to the back and disappears between the engine and firewall.
 

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2003 chevy trailblazer_ls
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It's normal for the rpm's to drop just a bit when the AC is on, due to the increased load the compressor puts on the engine. Mine will drop 50-100 when I turn the AC on.
We all have the same drop. This makes the compressor worthless till higher rpms. That not being the question, i'll hush!
 

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2003 chevy trailblazer_ls
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At the moment I am unable to speculate as to what the wire harness is for but you are likely correct.

Regarding the need for a code reader/live data scanner, yes, you do need one of your very own because the ones from the part stores that you use are unable to show you the live data, and more importantly, save the live data you are monitoring, so that puts you at a major disadvantage.

If you have an Android device, I recommend getting this Bluetooth OBDII dongle:


And then install the Torque Pro app (~$5.00) from the Google Play store. A very effective and powerful pair!

Also, you need a decent Digital MultiMeter (DMM).
Kv, PLEASE LISTEN.. this one is factual. I have both and it will blow your mind. PS i have no profit in this issue.
 

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2002 gmc envoy_slt
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We all have the same drop. This makes the compressor worthless till higher rpms. That not being the question, i'll hush!
Exactly... It's close to a miracle to start either one of my Envoys on a cold start and have the Ac actually cool off while in idle during the Texas summer heat.
Literally i will drive around the block while my family is finishing getting ready and come back home an park so the Ac will run properly while in idle!
Worse on my 2004 Envoy
Is it just me??!
 

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'05 Chevy TB EXT
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Exactly... It's close to a miracle to start either one of my Envoys on a cold start and have the Ac actually cool off while in idle during the Texas summer heat.
Literally i will drive around the block while my family is finishing getting ready and come back home an park so the Ac will run properly while in idle!
Worse on my 2004 Envoy
Is it just me??!
I don't think there's any need for AC in Montana, but my wife demands it ... and lately we've been hitting 95°F or so.

OK -- we've got 2 2005 GM products --- a Silverado Crew Cab K1500 with HVAC and it takes a trip around a 1-mile block to get it cold.

My 2005 TB EXT is pretty much the same way --- but maybe only 3/4 of a full block to get it cold both front and rear.

So ---> no --- I don't think the vehicle is at fault --- and that leaves just you ( :) )

FTR --- I took the AC out of both my 86 K5 Blazer and my 1989 Isuzu Amigo - and I was living in Concho, AZ at the time.

I hate AC.
 
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