RPM surge

[shelhamer72993]

When I’m driving the truck, every 3 to 4 seconds the RPMs surge about 50 to 100 almost as if it were going to change gears or something but even in 8th this happens. the truck thrust forward a tiny bit. It’s almost un noticeable, but I can notice it. No check engine lights and I just replaced the cam the lifters, timing chain, coil packs, and spark plugs. Diablo predator 2 tune with MDS delete kit.

 

[Brandon-w]

Who tuned it

 

[Daw14]

Have you cleaned the throttle body ever ?

Check your intake manifold bolts , they should be torqued to 108 inch pounds. If it’s sucking air that can cause issues. This should be done yearly,as they tend to become loose often.

 

[shelhamer72993]

Who tuned it

It’s a predator two handheld tuner. Everything that was replaced and it was stock specs.

 

[shelhamer72993]

Have you cleaned the throttle body ever ?

Check your intake manifold bolts , they should be torqued to 108 inch pounds. If it’s sucking air that can cause issues. This should be done yearly,as they tend to become loose often.

Everything was cleaned when I did the swap. I’ll double check the manifold bolts but wouldn’t that cause a regular or sporadic RPM changes versus a consistent 3 to 4 seconds?