Slight Jump In Rpm At Idle.. Please Advise

[whtailhunter319]

Hey guys, any input on this would be appreciated. Have and 01 Silverado with a duramax. Im not getting a check engine light but when at idle approx every 45 seconds the RPM's jump maybe 100rpm and its so fast the tach hardly reacts. Any ideas on what this might be a prelude for failure? Ive changed fuel filter, air filter and oil.

[94blackcamaroz28]

I used to have an 02 and it would do the same thing. Believe it was the FPR (fuel pressure regulator) that needed to be replaced. I never got around to getting it replaced and drove it around like that for 4 years without any problems.