08 Silverado Part Throttle Hesitation
08-23-2016, 09:04 PM
#1
Launching!
Thread Starter
08 Silverado Part Throttle Hesitation I have a 2008 Silverado 1500 5.3 with a 4l60e I believe, Z71 package 2wd.
Ive been having this part throttle hesitation for a while now and I cant figure it out.
It starts happening around 1800 RPMS when Im going about 65mph and it only happens if I ease into the pedal at speed.
So at about 1800 RPMS if I let off the gas a little and ease back into it, it makes a burrrrrr noise with a slight vibration but will clear up as I accelerate harder.
If I go from a stop and accelerate through, no problems.
It doesnt do it if I accelerate hard.
I can always step on the gas and power out of it but if I keep the pedal there it makes this burrrrrr noise that I can feel through the gas pedal. Its irritating and it only seems to be getting worse.
That 1800 RPMS seems to be the sweet spot for the issue. I can keep my foot on the pedal and it will burrrrrr as long as I hold it there at that RPM. If I step on the gas more it goes away.
Ive replaced plugs and wires and I gave the throttle body and MAF a good cleaning with no luck
Any ideas?
Ive been having this part throttle hesitation for a while now and I cant figure it out.
It starts happening around 1800 RPMS when Im going about 65mph and it only happens if I ease into the pedal at speed.
So at about 1800 RPMS if I let off the gas a little and ease back into it, it makes a burrrrrr noise with a slight vibration but will clear up as I accelerate harder.
If I go from a stop and accelerate through, no problems.
It doesnt do it if I accelerate hard.
I can always step on the gas and power out of it but if I keep the pedal there it makes this burrrrrr noise that I can feel through the gas pedal. Its irritating and it only seems to be getting worse.
That 1800 RPMS seems to be the sweet spot for the issue. I can keep my foot on the pedal and it will burrrrrr as long as I hold it there at that RPM. If I step on the gas more it goes away.
Ive replaced plugs and wires and I gave the throttle body and MAF a good cleaning with no luck
Any ideas?
08-23-2016, 10:44 PM
#2
Whats the wideband say in that region?
First step is verify a/f ratio is correct based on load. That sounds like 4-6" of Hg of vacuum in that range, so an a/f ratio of 14.0 or 13.9 is a safe bet. You will probably see the a/f fluttering into the 15's or 16's when you notice the hesitation, it needs more fuel in that part of the map probably.
Otherwise, if you have a maf sensor, it might just be dirty.
First step is verify a/f ratio is correct based on load. That sounds like 4-6" of Hg of vacuum in that range, so an a/f ratio of 14.0 or 13.9 is a safe bet. You will probably see the a/f fluttering into the 15's or 16's when you notice the hesitation, it needs more fuel in that part of the map probably.
Otherwise, if you have a maf sensor, it might just be dirty.
