ISL and hesitation and chk engine lite

Ivylog wrote:
The VGT turbo needs to be exercised to keep carbon from building up. Repeated hard accelerations may help clean it if your ISL has a VGT. What year ISL? Adding your rig's info to your profile helps.

LOL and thanks it gets plenty of hard accelerations when driven
Iam hoping it can be repaired or easly replaced if it turns out to be the problem. 2008 ISL

The VGT turbo needs to be exercised to keep carbon from building up. Repeated hard accelerations may help clean it if your ISL has a VGT. What year ISL? Adding your rig's info to your profile helps.

11178adm wrote:
defiantly get the codes checked, it sounds like it may be the variable geometry turbo is starting to stick, the turbo actuator has sensors and is calibrated to the turbo and if it does not respond to the ecm command the check engine light will light, the ecm keeps trying to move the vgt slide and if it moves as commanded the engine will respond and the check engine light will go out. hopefully it turns out to be something cheaper, or even under warranty
good luck and keep us informed what you find out

sounds plausible to me for sure. thanks

defiantly get the codes checked, it sounds like it may be the variable geometry turbo is starting to stick, the turbo actuator has sensors and is calibrated to the turbo and if it does not respond to the ecm command the check engine light will light, the ecm keeps trying to move the vgt slide and if it moves as commanded the engine will respond and the check engine light will go out. hopefully it turns out to be something cheaper, or even under warranty
good luck and keep us informed what you find out

OLYLEN wrote:
Or could be turbo lag do to a leak of post turbo air. Or exhaust leak so it takes more time for the turbo to overcome the leak and build pressure. Do you have a boost gauge? Lack of boost pressure could be the cause.

LEN

lack of boost pressure would be a constant power lose, this only has poor power upon take off for A very short time and once the check engine lite comes on it runs fine and is good till the next time
(never know when)

Or could be turbo lag do to a leak of post turbo air. Or exhaust leak so it takes more time for the turbo to overcome the leak and build pressure. Do you have a boost gauge? Lack of boost pressure could be the cause.

LEN

Ok guys thanks for all the replys. Hopefully the code pulled by the shop next week will tell the tale
what strikes me funny is as soon as the lite comes on it runs perfect
usually a motor runs good until the lite comes on this is the total opposite

Any bucking/hesitating of my ISL has been fuel filters BUT it's usually been while under load going up a hill. One time when after a big change in temp the fuel line at the tank was letting air in causing it to buck going up a hill.
My exhaust is clean... no black smoke on takeoff except when above 6000' and then there will be a small amount of black until the boost comes up when starting from a stop.

The easiest and cheapest first fix for a fuel problem is to change the filters. My ISL had two.

Is there black smoke when this happens? It may be fuel filters as said above or possible air filter. It could also be a turbo problem losing boost, but I suggest to have the codes read.