Has anyone fixed a surging idle?

[renegadedooer]

My truck has 155k on it and runs awesome. I have 48v on the ficm. T6 oil, ELC, 4* Delta. I have Quicktricks tuning. No matter what tune its on the Idle surges. Not all the time. Sometimes I be a McDonalds and it wants to ram me ahead, other times its smooth as silk. I ICP is new. I am thinking injector or IPR? Anybody have the same issue and figure it out?

[2003kingranch]

its done that 3 times to me before. no idea what it is. sitting at a stoplight and it try's to go. basically like your power braking it.

[renegadedooer]

Yup, most of the time its not that bad but every now and then... WHoa!

[Heathrm]

Did you change out the ICP Sensor pigtail at the same time? Could be soaked in oil. Quick check is to unplug the sensor and see if it still does it. If it doesn't, it is likely your sensor.

[renegadedooer]

Would cleaning the pigtail in electrical contact cleaner work?

[Heathrm]

It can't hurt. I would at least take a look at the connector and see if it is oil soaked. Cleaning it might help some, but I don't know if it will fix it, if it is soaked. Does it do it to some degree all the time? Is it always present, just the degree that it surges differently? Does it do it at idle in park?

[renegadedooer]

Some days it runs perfect. It surges with no pattern. I can shut the truck off if its doing it, come back in an hour and it might not do it for a day or so. I never know.

[Hadley]

My 04 has done it to me twice now in the past 3 weeks, I am going to check the ICP sensor plug and see what mine is like.

[Heathrm]

On a side note, my truck did this very rarely at one point. It turned out to be the FICM. It was a very light surge, would throw an injector balance soft code, not CEL, everytime is happened.

[renegadedooer]

Funny you say that about the FICM. I soldered mine. Its borderline, 47-48 most of the time but occasionaly goes to 46. Will read 45 when cranking and when cold.