Hey all, I'm new here but have been a member on FSC.com and GMFS.com for a while. I'm trying to figure out what's wrong with my Tahoe and am completely stumped. Hopefuly I'm posting in the right section...

Vehicle is a 2000 2wd NBS Tahoe with 5.3. The only real "mods" are just a K&N FIPK, TB bypass, and a Magnaflow muffler dumped in front of the axle. Both have been on for quite some time.

Here goes. I've got a bad hesitation when accelerating from either a dead stop and also on the road when in OD (around 60mph or so.) When off the line it has to be a pretty good amount of throttle for the problem to occur and when at higher speeds, if the truck downshifts, then there is no issue.

I've done most of the obvious including new fuel pump, fuel pressure regulator, fuel filter (All Delco parts), new-ish plugs (about 15k on NGK TR-55s) stock wires, new high flow cats (old ones tested to be clogged pretty good) and MAF cleaning. Fuel pressure is good when ign. on and vehicle running. There are no codes being thrown.

I'm stumped and figured maybe someone here can shed some light onto my situation. Thanks in advance.

 

might try cleaning the IAC control ( i think thats what it is )

my dads tahoe was doing the same thing but only at idle and it fixed it

 

get some 3M throttle body cleaner
completely remove your t/b and put it in a pan and get a rag and clean away

you can also remove the iac and swab the inside where the plunger goes (good idea)

if that dosent do it you may have an intake leak this is how my truck hesitation started i tried everything and finny figured out the intake was warped (it does it all the time, but mostly when cold)

i also had a bad hesitation when i installed some ngk tr-55ix's the end kept comming unscrewed so i swapped them for a fixed set

-Erik

 

Alright, I'll try the TB and the IAC and we'l see what we come up with...

 

Yeah! Get that gunk cleaned out of there and report back.

These things are notorious for that. You should probably clean it on a regular basis.

Welcome aboard. Stick around here too long and you'll spend some serious cash.

 

WELL....


I've cleaned the TB and IAC and there is still a minor bit of hesitation above and beyond the typical DBW throttle system's sluggish response, but it did improve performance quite a bit.

Also, My truck threw a few codes- a cat. code Bank 2 right side, P1515 and P1514. I understand the last two to be related to the throttle actuator, but after a reset, they still haven't come back on in about 100 miles. Damn.

What now?

 

give it some learn time to re-adjust itself

 

how is this thing driving?

any better?

 

Try some fuel injector cleaner, the injectors can get clogged from time to time, it happened to me once. If not that you may need a new fuel filter. The little things make a difference.

 

yeah i'm going to change the fuel filter tuesday it's on the lsit

i'm also going to ditch the K&N for the stock box and a new filter

whats everyone using for fuel inj cleaner now adays???