slow engine deceleration when shifting between gears. any way to stop this from happening?

claytonbretveld
5

Asked by claytonbretveld Feb 21, 2013 at 08:57 PM about the 1998 GMC Sierra 1500 K1500 SLE 4WD Standard Cab SB

Question type: Car Customization

i have a 98 gmc sierra 5.7 5 speed. when i push in the clutch and go to shift to the next gear the rpm hangs there for a few seconds and im sure it has something to do with smooth shifting but it bugs me because im used to driving non electronic vehicles. also if i leave it in gear and clutch still engauged when i let off the gas it takes about five seconds before the engine actually starts to decelerate. is there any way to make the engine rpm drop as soon as i let off?

8 Answers

tenspeed
57,075

There's a dash-pot type of affair that keeps the throttle plate from slamming shut. The slow closing throttle burns the fuel mixture cleaner. I've noticed it too with my manual tranny vehicles.

claytonbretveld
5

well if you rev it up in neutral it drops like it should but if its in gear it has that funny lag before it starts dropping. so i just wondered if i could change that somehow

7jimmy7
12,005

their is a switch under dash that tells the pcm clutch angle ,connected to lever arm,remove and clean or replace,maby cure rev issue

Alex Nazarian
845

Possible vac leak, tps or iac issue. Check your DTCs and report back.

claytonbretveld
5

all systems are good no codes or leaks. ive driven a few of these trucks and they all do the same thing so i think its supposed to do it but i dont want it to.

Michael Tutty
4,915

They are designed to do this as part of the emissions control system. It is, in my opinion, plain dangerous in certain circumstances. There is an aftermarket attachment that can be fitted that does away with the throttle lag. I makes a huge difference to throttle response both when you add and when you release. Any good performance shop should be able to steer you in the right direction. Failing that, check LMC.

claytonbretveld
5

do you know what the part is called? cant seem to find anything

Andrew Olsen
6,745

I've driven a few of 5 speed chevy's and they all have done this. The 5 speed trans in these trucks isnt designed to be quick shifted, It normally holds rpm's up after clutch release for only 1 sec. It's normal operation and will only be a problem if you try to float gears or something. It's not a throttle lag as if still in gear it should still decelerate as soon as you let off the pedal. If it doesnt then i'd worry about it. Also when cold it will have a high idle and magnify the effects of this system.

Your Answer

Add photo

Related Questions

  • Computers 1 answer

    What would happen if I took a computer from a 2000 Tahoe with a 350 vortec and put it in a 98 GMC Seirra with a 305 Vortec, would it be like a power chip up grade or would it even start?

    1998 GMC Sierra 1500

    -

    Car Customization

  • Speedometer doesn't work and transmission doesn't shift gears. 18 answers

    The speedometer stays at 0 all the time. When the transmission is in drive it won't come out of 1st gear. Reverse works fine, and if I manually put the transmission in 1st or 2nd it works fine. 199...

    1999 GMC Sierra 1500 SLT 4WD Extended Cab LB

    -

    Maintenance & Repair

  • rough idle, stalling, loss of power. 195 answers

    o2 sensor code 44 (lean) Replaced: coolant temp sensor, tps, map sensor, fuel filter, and o2 sensor. It will run normal on occasion but only lasts about 45 seconds or so. I don't think its the torqu...

    1995 GMC Sierra 1500 K1500 SL 4WD Extended Cab Stepside SB

    -

    Maintenance & Repair

  • Why wont my truck start? 2 answers

    I was driving to work and suddenly the truck starting idleing rough at stoplights and had decreased exceleration. My oil pressure gauge was normal, my heat guage was normal, but my battery gauge did a...

    1994 GMC Sierra 1500

    -

    Maintenance & Repair

  • I put my truck into drive or reverse n it will not move at all what is causeing this to happen 58 answers

    2003 GMC Sierra 1500 SLT 4WD Extended Cab LB

    -

    Maintenance & Repair

Sierra 1500
Looking for a Used Sierra 1500 in your area?
CarGurus has 57,400 nationwide Sierra 1500 listings starting at $1,995.
ZIP:

Search GMC Sierra 1500 Questions

GMC Sierra 1500 Experts

#1 dragonflyoffshore
dragonflyoffshore
Reputation 1,790
#2 John Saffrahn
John Saffrahn
Reputation 1,340
#3 Glenn Clingenpeel
Glenn Clingenpeel
Reputation 1,030
View All

Related Models For Sale

Used Chevrolet Silverado 1500"
2,518 Great Deals out of 170,475 listings starting at $650
Used Ford F-150"
2,994 Great Deals out of 151,632 listings starting at $1,000
Used Dodge Ram Pickup 1500"
812 Great Deals out of 14,487 listings starting at $1,495
Used Toyota Tacoma"
703 Great Deals out of 24,308 listings starting at $2,495
Used Chevrolet Tahoe"
965 Great Deals out of 28,481 listings starting at $2,700
Used GMC Yukon"
341 Great Deals out of 9,378 listings starting at $2,295
Used Ford F-250 Super Duty"
700 Great Deals out of 36,172 listings starting at $1,995
Used GMC Sierra 2500"
4 Great Deals out of 174 listings starting at $5,995

Used Cars For Sale

2015 GMC Sierra 1500 For Sale
29,659 listings starting at $37,917
2014 GMC Sierra 1500 For Sale
73 Great Deals out of 11,307 listings starting at $17,861
2013 GMC Sierra 1500 For Sale
135 Great Deals out of 2,748 listings starting at $15,495
2012 GMC Sierra 1500 For Sale
155 Great Deals out of 2,598 listings starting at $10,488
2011 GMC Sierra 1500 For Sale
151 Great Deals out of 2,768 listings starting at $10,990