IACV idle air control valve....

[Wilecoyote]

My 98 5.7 Vortec starts quick w a touch of the key.I've noticed recently it has a shake about every 2 or 4 seconds idling in park or N. Shakes the truck and it does not go away idling for 5 mins. or more. Would this be the problem?

 

[Schurkey]

Verify fuel pressure, verify cap/rotor/plug wires/plugs/cranking compression, then connect a scan tool.

The answer is probably in the data stream somewhere.

 

[Wilecoyote]

Had a 1/4 tank of gas in it, parked on a slight hill, the front was uphill when it was shaking. Filled it up and the shake got gone.

 

[zer0Limitz]

My 98 5.7 Vortec starts quick w a touch of the key.I've noticed recently it has a shake about every 2 or 4 seconds idling in park or N. Shakes the truck and it does not go away idling for 5 mins. or more. Would this be the problem?

this sounds like what my truck is doing. I started it up for first time in a month or so. When sitting in park idling, or in drive idling/stopped, the engine is idling rough. it will make the truck shake. i was worried it was going to die but didnt, just idled back but when you push on gas no issues. From what im seeing the idle air control value might be the cause of the issue. have you had anymore luck with figuring out the situation?