rojo_143 Posted September 11, 2008 Report Share Posted September 11, 2008 My truck just recently started to idle rough with my A/C or defrost blower on. I recently got my truck tuned by justin @ Blackbear performance. Could the tune have caused my truck to start idleing rough? It only does it if the the blower is on and it only seems to do it every 6 sec or so like whe the a/c compressor kicks in. Quote Link to comment Share on other sites More sharing options...
Rausche Posted September 11, 2008 Report Share Posted September 11, 2008 (edited) My idles a little funky too (same Tuner here, BTW), RPMs drop a little and the motor shakes likes it's trying to recover. I didn't see it as a big enough issue to complain about, and IMO it's not doing any damage and I've learned to live with it. PS: I'm sure Justin would address the problem if you complained about it. Edited September 11, 2008 by Rausche (see edit history) Quote Link to comment Share on other sites More sharing options...
Rays B4U Posted September 11, 2008 Report Share Posted September 11, 2008 Mine just started doing it this summer too. I've had my pcmforless tune for several years and this is the first I've felt it. I'll be sitting at a stop light with my foot on the brake and I will suddenly feel the engine stumble then recover making it want to lurch forward. Quote Link to comment Share on other sites More sharing options...
NashSS Posted September 11, 2008 Report Share Posted September 11, 2008 ive had the same issue with mine sometimes except when mine does it my ac turns to heat until I give it some gas. Its aggravating Quote Link to comment Share on other sites More sharing options...
Rays B4U Posted September 11, 2008 Report Share Posted September 11, 2008 Found this in the Service Manual. This sounds like what mine does, I'm going to give the throtle body a good cleaning since it's never been done. ============================================================================ 2003 Chevrolet Chevy K Silverado - 4WD 4.8 5.3 6.0 LM7 LQ4 LQ9 LR4 Engine - Idle Surge , Rough Run , Near Stall or Erratic Idle - kw ac code driveability fluctuation intermittent #PI01470 - (Oct 28, 2003) 4.8 5.3 6.0 LM7 LR4 LQ4 LQ9 Engine . When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms. Condition/Concern: Note: Only vehicles equipped with an electronically actuated throttle body are effected. The vehicle may exhibit a condition that can be described as an erratic idle, idle surge, rough run, or near stall. The condition is intermittent, but can be relatively easy to duplicate at idle, with the engine at operating temperature, in gear, and with the A/C on, although the A/C does not need to be on. In most cases no DTCs will set. Recommendation/Instructions: To repair this condition, you can select from the following two recommendations. 1. Clean the throttle body using the following method below that is published in the Delphi Automotive Systems 21D-2001 manual and referenced in SI. 2. Service Information: NOTE: Do not immerse the throttle body in any immersion type cleaner. Soaking the throttle Bbody in liquid cleaners will wash the lubricant from the sealed throttle Sshaft bearings and wash the factory applied DAG material from the throttle valve. Also do not expose the throttle position (TP) sensor and Idle Air Control (IAC) valve to liquid cleaners as damage to these parts may result. THE THROTTLE BORE AND VALVE DEPOSITS MAY BE CLEANED ON-VEHICLE, USING GM CLEANER 1052626 OR GM X-66A. USE A SHOP TOWEL TO REMOVE HEAVY DEPOSITS. Replace the throttle body assembly if the situation warrants replacement vs. cleaning as described above. . Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms. Models: (00, 01, 02, 03, 04 Chevrolet Silverado Truck C1, C2, C3) and (00, 01, 02, 03, 04 Chevrolet Tahoe C1, C2, C3) and (00, 01, 02, 03 04 Chevrolet Suburban, C1, C2, C3) and (00, 01, 02, 03 04 GMC Sierra Truck C1, C2, C3) and (00, 01, 02, 03, 04 GMC Yukon C1, C2, C3) and (00, 01, 02, 03, 04 GMC Yukon XL C1, C2, C3) and (02, 03, 04 Cadillac, Escalade, C6) and (03, 04 Cadillac, EXT, C1) and (02, 03, 04 Chevrolet, Avalanche, K1, K2) and (02, 03, 04 Chevrolet Silverado Truck K1, K2 K3) and (02, 03, 04 GMC Sierra Truck K1,K2,K3) and (02, 03, 04 Chevrolet Tahoe K1,K2,K3) and (02, 03, 04 Chevrolet Suburban K1,K2,K3) and (03 Chevrolet Camaro) and (02, 03, 04 Chevrolet Corvette) and (03 Pontiac Firebird) and (02, 03, 04 GMC YUKON K1, K2, K3) and (02, 03, 04 GMC YUKON XL C1, C2, C3) and (00, 01,02, 03, 04 GMC YUKON XL K1, K2, K3) and (03, 04 GMC S1 T1) and (03, 04 Chevrolet S1 T1) Quote Link to comment Share on other sites More sharing options...
Jond983 Posted September 11, 2008 Report Share Posted September 11, 2008 Mine just started doing it this summer too. I've had my pcmforless tune for several years and this is the first I've felt it. I'll be sitting at a stop light with my foot on the brake and I will suddenly feel the engine stumble then recover making it want to lurch forward. mine does that too i guess it's just when the a/c kicks on and off with the fans? Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted September 11, 2008 Report Share Posted September 11, 2008 Could be a dirty throttle body, could also be from a compressor that it starting to show age. Sounds as if the compressor is putting a large load on the engine dragging the idle down when the clutch locks up. Could also just be that you need the target idle speed bumped up in your tune. My stock idle was 550 and was somewhat rough, when I got my Wheatley tune I had it bumped up to 600 and it smoothed out. Quote Link to comment Share on other sites More sharing options...
Wheatley Posted September 11, 2008 Report Share Posted September 11, 2008 Keeping your throttlebody cleaned can help keep idle consistant and more smooth Quote Link to comment Share on other sites More sharing options...
benjaminh2 Posted September 12, 2008 Report Share Posted September 12, 2008 I clean my throttle plate twice a year, it's amazing how fast crap builds up in there. i also run 8oz of lucas fuel system treatment every other fill up, and i've never had any idle issues. 04 SS with 33k... Quote Link to comment Share on other sites More sharing options...
Rausche Posted September 12, 2008 Report Share Posted September 12, 2008 I clean my throttle plate twice a year, it's amazing how fast crap builds up in there. i also run 8oz of lucas fuel system treatment every other fill up, and i've never had any idle issues. 04 SS with 33k... Are you tuned? Quote Link to comment Share on other sites More sharing options...
benjaminh2 Posted September 12, 2008 Report Share Posted September 12, 2008 (edited) Are you tuned? yup. base idle set at 550. Edited September 12, 2008 by gmperformanceguy (see edit history) Quote Link to comment Share on other sites More sharing options...
Rausche Posted September 12, 2008 Report Share Posted September 12, 2008 yup The issue here is that Rojo_143 and I both have a tune from the same tuner, and are experiencing the same idle issues. I doubt that we both need to clean our TBs, or even that the symptoms we have are even bad for the motor in any way. I'm not saying that a dirty TB won't cause rough idle, I'm just saying that in our case (myself and Rojo_143,) it is an issue with the tune. Clear things up? Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted September 12, 2008 Report Share Posted September 12, 2008 The issue here is that Rojo_143 and I both have a tune from the same tuner, and are experiencing the same idle issues. I doubt that we both need to clean our TBs, or even that the symptoms we have are even bad for the motor in any way. I'm not saying that a dirty TB won't cause rough idle, I'm just saying that in our case (myself and Rojo_143,) it is an issue with the tune. Clear things up? Like I mentioned before, have your target idle bumped to 600 and it will smooth out........ Quote Link to comment Share on other sites More sharing options...
benjaminh2 Posted September 12, 2008 Report Share Posted September 12, 2008 i agree. 600 rpm will prob make a noticeable diff, especially when the comp kicks on. Quote Link to comment Share on other sites More sharing options...
.justin. Posted September 12, 2008 Report Share Posted September 12, 2008 Hey Guys, Did it start this immediately after the PCM installation? Notice it in gear or park? Justin Quote Link to comment Share on other sites More sharing options...
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