Jump to content

GMC Idle Problem

hybridtj

Recommended Posts

hybridtj New Member

hybridtj

Posted
Posted

I have a 2001 GMC pickup with the 6L engine. Truck has about 45000 miles.

 

I have a problem where the truck stalls quite often, always under the same circumstances. When I am pulling into say a parking spot and am slowing down or braking, the rpms drop pretty low. Then when steering into the parking spot it is like the power steering pump adds just enough extra work to the low idling engine that my engine stalls. Once I restart the engine, the idle speed is always sufficient to run everything.

This never happens when just coming to a stop only. It is only when turning while coming to a stop. Its like the idle drops too far before it compensates back up.

Any suggestions about what to do or what the prob is? Air filter is clean, fuel filter is new, all that kind of stuff.

Any help would be appreciated.

hybridtj New Member

hybridtj

Posted
  • Author
Posted

Thanks for the reply. What is involved in having the PCM updated by the dealer?

 

One other thing that I was checking yesterday. If I am sitting at idle and I turn on the defroster for instance, the idle drops pretty low and then recovers. I can make it do that repeatedly if I keep turning it off and on. Why does the rpm drop so low like that? Is the idle just set too low?

 

Thanks

asepgrad98 Senior Enthusiast

asepgrad98

Posted
Posted

the idle drops because the defrost puts a huge load on the alternator. if your still under warranty then you may be able to get the dealer to update the PCM for free. otherwise 70$ or so.

hybridtj New Member

hybridtj

Posted
  • Author
Posted

Thanks. I guess I'll clean the throttle body and call the dealer. Do I just make an appointment and tell them that all I want done is to have the PCM updated? What does the anacronym PCM stand for exactly, so I don't sound stupid? Thanks again.

  • 1 month later...
GMike Enthusiast

GMike

Posted
Posted

Your problem sounds exactly like mine! Here is my post:

 

Any ideas what to check for this? I have a 2002 Escalade with around 60K miles. I have recently had the fuel filter replace, new Bosch Platinum +4 plugs, changed oil to Mobil 1 (w/Fram doubleguard filter). The truck runs strong, but after it gets warmed up and I come to a stop, the idle starts to drop below 500 RPM's. The PCM seems to catch it some of the time, and tries to keep the engine running, but occasionally it dies. I put it back in park and she starts right back up. Unfortunately, it just seems she wants to idle at too low an RPM.

 

I have a preditor programmer and can change a few things, but not idle (not for 2002). Any suggestions as to what to monitor, and or change? I also noticed the knock sensor retarded timing at WOT. So, I richened up the fuel mixture a little bit. So, far no difference regarding the "idle stall" problem when using the stock program or the preditor programmers standard performance tune.

 

Your help and suggestions are appreciated.

 

What did you find out? Did you find a fix? Throttle body cleaning work? I would love to know!

 

Regards,

 

Mike

GMike Enthusiast

GMike

Posted
Posted

Hey, thanks! That was a good link. I ran my VIN and the Engine Calibration mentions a "New calibration to address idle surge condition caused by throttle body coking, to be used in conjuction with throttle body cleaning."

 

So, I will use my programmer to se if the CVN# 0000E4E8 shows up in the PCM. If not, I guess I will need to show around at a GMC dealer (Cadillac is too expensive). I would think a chevy/GMC truck shop should be able to do both procedures, recalibrate and clean.

 

Any other suggestions? :rolleyes:

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • teamjnz
      Stabilitrak conversion to Z71

      By teamjnz · Posted

      Sounds like converting will be a bigger endeavor than I was thinking. This truck doesn't have 2Hi like the Suburban did. The Tahoe has 4Hi and 4Lo and a button to turn of traction control.   From what I understand the Stabilitrak uses open diff in the front and rear. When wheel speed is not the same the stabilitrak uses the ABS system to slowdown the spinning wheel(s) to transfer power to the slower non-spinning wheel(s). I thought the transfer case was open too. Being able to transfer power either more to front or rear depending on wheel spin. Maybe I miss understood some information with you saying and power transfer is 50-50. Thanks
    • PunchT37
      OCI, not when but why?

      By PunchT37 · Posted

      My brother has a 2007 Avalanche with afm 5.3. It`s got 176,000 miles. Runs like a clock. Never been apart. Co worker has a 2010 Tahoe with afm 5.3. 230,000 miles. Never been apart. Runs like a clock. So, even though cyl deac is a weak spot, they can go the distance.   BUT, these engines had the oil changed regularly, AND had 5w30 as spec. I wonder if they would have lasted this far on 0w20? I`ll bet not.
    • Chuck FB
      OCI, not when but why?

      By Chuck FB · Posted

      I certainly could be wrong but I hear of pickups far newer than that 2007 cutoff which may not be going to the wrecker but are having engine work done and be that a reman engine or new engine or trying to repair the existing engine. Some of it would be design issues as per the cylinder deactivation system that GM has and one of those lifters wiping out the cam and the question of oil changes moving the needle or not on that whole mess, or in the case of Ford pickup engines that have the long timing chains and wearing them out and the roller followers and phasers and some of that certainly goes back to oil change intervals. But in those various cases the truck has all sorts of life left in it and so the unfortunate owner and may be original owner or used market owner that is pouring money into repairs so the truck is not seeing the salvage yard yet but damage is happening by infrequent oil changes. A friends son had bought a 2018 I think it is half ton GM and it had some sort of extended or used dealer warranty on it and of course the lifter issue bites and its rattling and so the dealer had to swallow the bill and was at least 7000.00 and I think they only replaced what they felt they had to replace so yeah, I can see that being a ticking time bomb in the not too distant future. Would frequent oil changes cure all these engineering "marvels", probably not but some engine designs have shown that they do much better if the oil is changed a lot more often then if the manufacturer service claims are followed. New trucks cost so much that there is an incentive to keep the existing truck on the road by repairing. 
    • davester
      Tranmission stays in Low

      By davester · Posted

      get a good code reader, and find out what problems the truck has noticed by reading codes. cheap ones can only get basic engine codes, you may want to get one that can get codes from all the computers in your truck.
    • asilverblazer
      OCI, not when but why?

      By asilverblazer · Posted

      This is sort of my point, salvage yards aren't overflowing with all these 'poorly' maintained trucks - excellent/good/servicable condition otherwise, salvaged only as a result of a bad engine from poor oil change regiment.    In my area, there are no 2007 to newer gm trucks/suvs in any salvage yards. A few are in the 'recyclers' with very obvious reasons for being there - wrecked.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...