03 Tahoe stalls

93redzj

93redzj

Well-Known Member
Joined
Aug 29, 2005
Location
Albemarle
We just recently purchased an 03 Tahoe LT, it’s 2wd, 170k miles, no issues on the test drive or drive home from Lexington to Albemarle. However drove it to work in Concord the other day and on two separate occasions it stalled and died during a slow turn. Both were coming up to stop lights. Wife was driving it today and it did it to her, again, in a slow turn at a light. Not sharp turns or U turns, just regular ol turns. I have no idea where to even start with looking. I know it’s got a new battery and I check alternator for correct output. Those check out, but no idea what to look at next
 
93redzj said:
We just recently purchased an 03 Tahoe LT, it’s 2wd, 170k miles, no issues on the test drive or drive home from Lexington to Albemarle. However drove it to work in Concord the other day and on two separate occasions it stalled and died during a slow turn. Both were coming up to stop lights. Wife was driving it today and it did it to her, again, in a slow turn at a light. Not sharp turns or U turns, just regular ol turns. I have no idea where to even start with looking. I know it’s got a new battery and I check alternator for correct output. Those check out, but no idea what to look at next
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Check the harness that goes down in front of the driver's side head. It's a common pinch point and there are a few grounds in that bundle than can cause a dead skip or even kill it. Check battery terminals and the rest of your grounds too.
 
This is what that bundle looked like on my 6.0. It randomly died a few times and wouldn't restart (when it was raining) and I'd pull that away from the bracket and it would fire right back up.

20210815_165233.jpg
 
LBarr2002 said:
Check the harness that goes down in front of the driver's side head. It's a common pinch point and there are a few grounds in that bundle than can cause a dead skip or even kill it. Check battery terminals and the rest of your grounds too.
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Thanks I’ll check that out. I will say, it fires right back up without issue.
 
Silverado_Express said:
I would try cleaning the throttle body. They were notorious for a very low idle/ stalling at low speed and turns when they got dirty with carbon buildup.
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My first thought was ^^^

Or it being power steering related. If the pump or rack are failing they could be putting undue strain on the motor and lowering rpms. Easy test at warm idle, in gear foot on brake. Work the wheel to full lock and hold it there for a few seconds.
 
Ron said:
My first thought was ^^^

Or it being power steering related. If the pump or rack are failing they could be putting undue strain on the motor and lowering rpms. Easy test at warm idle, in gear foot on brake. Work the wheel to full lock and hold it there for a few seconds.
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I did that one already, that was one of my first thoughts as well seeing how it seems to do it in turns.

Here’s what I’ve found today. Fuel pressure with ignition “on” is around 45psi, running it drops to 25….now I thought if the pressure regulator was working properly, then when you remove the vacuum line from it, the pressure spikes? Is that correct? I removed the vacuum line and pressure stayed the same
 

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Ron said:
after seeing the pics, Im even MORE convinced Mike is right
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I was looking up some of the symptoms of those, the speedometer works fine, cruise control works, and there is no CEL. Common symptoms I seen were speedo not working or being erratic, cruise control not working and a CEL….could this still be a possibility?

Or is @Silverado_Express name Mike too? Lol I thought you were referring to @yager suggestion on the VSS
 
93redzj said:
I was looking up some of the symptoms of those, the speedometer works fine, cruise control works, and there is no CEL. Common symptoms I seen were speedo not working or being erratic, cruise control not working and a CEL….could this still be a possibility?

Or is @Silverado_Express name Mike too? Lol I thought you were referring to @yager suggestion on the VSS
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Yeah that was confusing on my part. I'm sorry.

I was referring to @Silverado_Express
 
Ok, more time to elaborate.

Fuel pressure does seem low to me. IIRC I thought it was supposed to be around 50 or 55psi. A quick Google search could confirm. I'm thinking 03 still had the return style fuel system and you would have an external filter on the frame rail. I would check that first if you are having low fuel pressure issues but if it is plugged and you do change it out, don't be surprised if the fuel pump itself dies in the next little while. It always seems like they burn up after being able to free flow again after being ran with a plugged filter.

I don't feel like this is your stalling issue because I see the fuel issue being more at speed and when fuel demand is high. Again, IIRC 03 was around the year the drive by wire (electric) throttle bodies were introduced on the trucks and basically the carbon buildup chokes them out vs the old drive by cable where you would just notice a sticky pedal. Can of carb clean and an old toothbrush. Don't be scared to push open the butterfly and scrub all around. I feel this will fix your issue.
 
Silverado_Express said:
Ok, more time to elaborate.

Fuel pressure does seem low to me. IIRC I thought it was supposed to be around 50 or 55psi. A quick Google search could confirm. I'm thinking 03 still had the return style fuel system and you would have an external filter on the frame rail. I would check that first if you are having low fuel pressure issues but if it is plugged and you do change it out, don't be surprised if the fuel pump itself dies in the next little while. It always seems like they burn up after being able to free flow again after being ran with a plugged filter.

I don't feel like this is your stalling issue because I see the fuel issue being more at speed and when fuel demand is high. Again, IIRC 03 was around the year the drive by wire (electric) throttle bodies were introduced on the trucks and basically the carbon buildup chokes them out vs the old drive by cable where you would just notice a sticky pedal. Can of carb clean and an old toothbrush. Don't be scared to push open the butterfly and scrub all around. I feel this will fix your issue.
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This
 
Silverado_Express said:
Ok, more time to elaborate.

Fuel pressure does seem low to me. IIRC I thought it was supposed to be around 50 or 55psi. A quick Google search could confirm. I'm thinking 03 still had the return style fuel system and you would have an external filter on the frame rail. I would check that first if you are having low fuel pressure issues but if it is plugged and you do change it out, don't be surprised if the fuel pump itself dies in the next little while. It always seems like they burn up after being able to free flow again after being ran with a plugged filter.

I don't feel like this is your stalling issue because I see the fuel issue being more at speed and when fuel demand is high. Again, IIRC 03 was around the year the drive by wire (electric) throttle bodies were introduced on the trucks and basically the carbon buildup chokes them out vs the old drive by cable where you would just notice a sticky pedal. Can of carb clean and an old toothbrush. Don't be scared to push open the butterfly and scrub all around. I feel this will fix your issue.
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Typically it has been while driving. However this morning as soon as I pulled out of driveway onto the road, it immediately started stuttering and cutting out. Might be noteworthy that vehicle is between 1/4 and E. Now these other issues have happened with plenty of fuel in tank. Just now with it low, does it seem to not wanna run right at all.

Cleaning throttle body is free and pretty simple, so should o just go ahead and remove it, clean it and see if it changes anything? If not just go ahead and plan on filter and pump? Our plan was to take this thing to Florida over Christmas to visit family and I’ve got the next two days off work to get it figured out.

Would the throttle body cause issues with fuel pressure??
 
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Ok so sounds like you have 2 problems, not just the stalling at idle/ low speed but also possibly a low power issue or other issues driving.

If it were me, I would do like you said. Clean the TB, don't even have to remove it. But if you do have a low fuel pressure issue, I would check the filter. "Normally" fuel pumps either work or they don't so low pressure is either a plugged delivery system (filter) or possibly split line inside of tank. Again if it was me and it was plugged i would go ahead and replace pump now vs side of the road OTW to Florida. Also don't buy the El cheapo fuel pump module. buy once, cry once and get a ac Delco or Bosch. The long interstate ride isn't going to be friendly on the old pump if you do only replace the stopped up filter.

*Edit
No, the dirty TB will not effect the fuel pressure
 
Silverado_Express said:
Ok so sounds like you have 2 problems, not just the stalling at idle/ low speed but also possibly a low power issue or other issues driving.

If it were me, I would do like you said. Clean the TB, don't even have to remove it. But if you do have a low fuel pressure issue, I would check the filter. "Normally" fuel pumps either work or they don't so low pressure is either a plugged delivery system (filter) or possibly split line inside of tank. Again if it was me and it was plugged i would go ahead and replace pump now vs side of the road OTW to Florida. Also don't buy the El cheapo fuel pump module. buy once, cry once and get a ac Delco or Bosch. The long interstate ride isn't going to be friendly on the old pump if you do only replace the stopped up filter.

*Edit
No, the dirty TB will not effect the fuel pressure
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Awesome, thanks man! I’ve made the mistake in the past of going el cheapo on important parts and paying for it shortly after. I’ll definitely pony up and get the right part for the job. I’ll tear into it tomorrow and hopefully be able to update that problem is solved!
 
What a pain in the ass this fuel pump is. Couldn’t get tank fully removed from vehicle due to the vent lines running to charcoal canister and the inability to get to them to get them removed. So I just dropped it, fought locking ring to get old pump out, finally won that battle only to lose the war of getting the stupid locking ring back on.
 
They make a tool, not sure if they have it as a loaner at like oriellys or advance. We had one at the dealership, just fits on the end of a ratchet or breaker bar.
The evap lines can fight you, I imagine pretty good on your back on the ground. Gotta squeeze the sides just right to release them
 
Silverado_Express said:
They make a tool, not sure if they have it as a loaner at like oriellys or advance. We had one at the dealership, just fits on the end of a ratchet or breaker bar.
The evap lines can fight you, I imagine pretty good on your back on the ground. Gotta squeeze the sides just right to release them
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Yeah I went ahead and ordered the tool, it should arrive tomorrow. I’m sure I’ll need it in the future as well. Yeah those lines at the canister are just about impossible to get to….and the one I really need to get to is on the bottom by the cross member with the other two lines above it. Rolling around on the gravel in the cold has me wanting to enlist the help of @jeepinmatt for this job lol
 
Might as well check that canister. The SUVs were bad about them blowing out the charcoal packing.

Also, 03 was sort of a split year. I've seen DBW returnless, DBW return, cable return, and cable returnless. GM didn't appear to be very consistent with that changeover that I can tell.
 
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