IDLE - DONE SO MUCH ALREADY - WHY!??! - 2004 TB LT 4X4

[webdawg]

My 2004 LT TB 4x4 stalls at idle. Not all the time, and I cannot predict it. It has never caused an issue. It is only when stopped and usually at a stop sign/red light.

It happens more when I have the AC on.

I have replaced the coils, intake gasket, fuel injectors, plugs, ignition switch, cleaned throttle body about 15k ago, and had a camshaft relearn done. I just have done all of this for other reasons, not because of this issue specifically.

Here is some food for thought:

I just got done towing a 6x8 trailer for about 1500 miles in really hot weather (TX) (This stall issue was happening before this) and I noticed that when I turned the AC on, the temp would go up a bit on the dash. I have never seen the temp go up ever. I ended up doing the entire tow without AC. Sure I got burnt, but my car did not. I noticed that also if for some reason if I really had to step on it, the temp would go up (kind of fast), but it would go down once I took it out of 4k RPM. Most of the time I did not mean to put the RPMs up that much but sometimes it just happens. I honestly do not know if the gauge is ever supposed to go up (because I need additional cooling) and I was going to post this in a different thread later but since I am having this issue I want you to know. BTW, when the trailer had hardly anything in it, it was doing the same thing but less. This is at least 100 degree weather at all times.

Another thing: When that AC compressor kicks on, you know it, the RPMS just seem to drop and the engine reacts. I think a slow reaction is really what causes the engine to shut off. What controls the engine load stuff? That is what lets the engine know that it needs to kick it up a notch to compensate? How does that work?

 

[Mooseman]

Did you disconnect the battery for 30 minutes when you cleaned the throttle body? You don't mention it.

 

[webdawg]

Did you disconnect the battery for 30 minutes when you cleaned the throttle body? You don't mention it.

I did, I cleaned it over a year ago though, you think it matters?

 

[gmcman]

Have you checked your TB recently for being dirty? How many miles on your plugs? I would take a look at the TB and see if it's gunked up. Also, what condition is your air filter? Have you replaced your fuel filter?

 

[webdawg]

Have you checked your TB recently for being dirty? How many miles on your plugs? I would take a look at the TB and see if it's gunked up. Also, what condition is your air filter? Have you replaced your fuel filter?

I have done this all. I mean, I just clean the TB. KN air filter, fuel filter 20k ago. Plugs are new heh. like 20k ago too.

 

[gmcman]

I have done this all. I mean, I just clean the TB. KN air filter, fuel filter 20k ago.

I was curious if you have checked your TB in the recemt days to verify its condition.
So you haven't cleaned your throttle body in 20K miles is what I'm gathering. ..if so I would clean it again and pull fuses 10&28 before you start to reset your PCM.

When you get it back together, turn key on and let it sit for a min or 2, then start engine and let it idle for about 5 min.

At no time should you touch the gas pedal during the relearn.

 

[webdawg]

I was curious if you have checked your TB in the recemt days to verify its condition.
So you haven't cleaned your throttle body in 20K miles is what I'm gathering. ..if so I would clean it again and pull fuses 10&28 before you start to reset your PCM.

When you get it back together, turn key on and let it sit for a min or 2, then start engine and let it idle for about 5 min.

At no time should you touch the gas pedal during the relearn.

Thanks for the procedure. I will do it this weekend and report back in about a week or two. Do you think it could be a bad throttle body in general? Any way to test the TB?

 

[Mooseman]

The throttle body is pretty self-diagnosing so if there was an issue with it, it would throw a code and/or put it in REP. Same with the pedal sensor.

 

[therealsethallen]

The throttle body is pretty self-diagnosing so if there was an issue with it, it would throw a code and/or put it in REP. Same with the pedal sensor.

When my pedal sensor failed, the entire pedal assembly had to be replaced. It thew a code, and stuck it in REP mode, I had to have it towed three mies! I hate electronic throttles. So, my guess is that isn't the issue.

 

[webdawg]

I did the clean and it is working better. Thanks for the help, I am going to create another thread for the cooling issue now.

 

[Nexus1155]

couple things. You need to get a scanner on there to see whats going on. Even this is a bandaid i believe with resetting the battery during cleaning. Even though you did a case relearn that solenoid could have junk inside causing it to fall on its face. Personally I used hptuners to scan and tune to bump my idle up because of the stalling feeling. its targetted to idle around 615rpms iirc. i bumped up to 650-700. a little more stable.

Is this a 4.2? Towing? I use to do that and had a few issues. You NEED a trans cooler. first and foremost. You should change out the clutch fan to electric because mine couldn't handle it for some reason when towing and blasted out once a year along with waterpump.

If you tow, you need a cooler and a scanner to say the least on these vehicles to be safe i say.

 

[tsmith1156]

Sounds like the issues I'm running into with mine, it isn't stalling anymore but the rough idle is noticeable. Maybe I'll look at the throttle body again

 

[webdawg]

Even though you did a case relearn that solenoid could have junk inside causing it to fall on its face.

Is this a 4.2? Towing? I use to do that and had a few issues. You NEED a trans cooler. first and foremost. You should change out the clutch fan to electric because mine couldn't handle it for some reason when towing and blasted out once a year along with waterpump.

If you tow, you need a cooler and a scanner to say the least on these vehicles to be safe i say.

Can you please recommend a kit for the electric fan. It looks as though I will have to send in my PCM too for this?

Are you talking about the camshaft actuator solenoid? I thought the CASE was for the crankshaft.

 

[Mooseman]

For towing, I would not recommend e-fans (been there, done that). They would never be able to move as much air as the mechanical clutch fan. You could get a tune to turn off the fan codes and get a regular thermal clutch from a 2008 TB to replace the electro-viscous fan clutch. Our radiators are marginal, which is why GM never went with e-fans in these trucks. Plus they're a PITA to get working right with A/C, which I had also found performance to be lacking.

For the actuator, it's not a bad idea to pull it out and inspect it. If there is oil inside the plug, it's failing. If it's otherwise fine, you can clean the screens and reuse it. A CASE relearn is not necessary.

 

[Nexus1155]

True what he said about the stock fans working well, but I had issues myself when towing. I got the LS1 fan from Autozone. Dual fans and a nice nice flexalite controller. the controller makes all the difference of a set it and forget it system. maybe spent $220 in total. I have hptuners myself so it makes a big difference.

I never knew what a case relearn did other than for when you do a tune and have to reset everything. Cam angle sensor crank angle sensor. Have no idea but thought you were talking about for the solenoid/actuator.

Do you not have a tune at all yet? Where do you live? It could extend the life of your tranny exponentially.

 

[webdawg]

True what he said about the stock fans working well, but I had issues myself when towing. I got the LS1 fan from Autozone. Dual fans and a nice nice flexalite controller. the controller makes all the difference of a set it and forget it system. maybe spent $220 in total. I have hptuners myself so it makes a big difference.

I never knew what a case relearn did other than for when you do a tune and have to reset everything. Cam angle sensor crank angle sensor. Have no idea but thought you were talking about for the solenoid/actuator.

Do you not have a tune at all yet? Where do you live? It could extend the life of your tranny exponentially.

I have not tuned. I am around Austin, TX right now.

Does anyone think the addition of a Transmission Cooler would help on this?

 

[Nexus1155]

well since you are making extra posts its going to be hard to track things down. All together I think you need to get it scanned with someone who is a tuner and maybe tuned at the same time if you have a few bucks. They would be able to confirm a few things temperature and health of vehicle wise to calm a few thoughts on the vehicle.

It's hard to bench diagnose man...

I would wobble the clutch fan back and forth to test if the waterpump is faulty or if any coolant is leaking down behind fan. could be causing raised temp

Usually when that goes the thermostat / temp sensor are not too far behind it all. could be causing the raised temp and or stalling...

Basic Tranny Cooler with GM radiator adapter

Tune / Scan $~100-$150 talk to lime maybe? but he cant remotely scan it. Makes the truck so much better, especially when towing.

 

[Mooseman]

A tune is not absolutely necessary if you replace it with a stock EV fan clutch. A tune and a thermal clutch would cost about the same, be more reliable and would also get the benefits of the tune. Cost of the thermal clutch and tune would be about the same as the EV clutch.

Yes, an auxiliary cooler would be good, even if not towing.

 

[AzTruckGuy]

My 2004 LT TB 4x4 stalls at idle. Not all the time, and I cannot predict it. It has never caused an issue. It is only when stopped and usually at a stop sign/red light.

It happens more when I have the AC on.

I have replaced the coils, intake gasket, fuel injectors, plugs, ignition switch, cleaned throttle body about 15k ago, and had a camshaft relearn done. I just have done all of this for other reasons, not because of this issue specifically.

Did you ever figure out your stall issue?

 

[webdawg]

I did a throttle body clean and computer reset and it is working great. Except that it seems to be coming back. I think right now I have a bad fan clutch.

 

[Mooseman]

Did you test it? I know you were asking about that.

 

[tsmith1156]

I'm gonna have to see about that computer reset, mine has slowed down a lot since I did my valve cover gaskets but it is still there

 

[AzTruckGuy]

I did a throttle body clean and computer reset and it is working great. Except that it seems to be coming back. I think right now I have a bad fan clutch.

Same here with the stall issue it seems to be coming back...I had another member state that he replaced his charcoal canister and it cured his stall issue..I haven't replaced mine since its $140 for that part and Id rather buy other items for now