1990 454SS TBI rough idle, but under throttle no problem issue...

[spistols]

As the title states, under no throttle my 1990 454SS 127K runs like it has a lumpy cam, but under throttle it runs OK. Also has a gas like, but not pure gas odor. Does it have something to do with anything vacuum related or is there an idle adjustment that worked its' way loose or broke?

 

[Fredridge]

I think I just started having this exact same issue.

hopefully someone knows what this is.

Mine has died a couple of times also, mostly when I just take out of park and start moving

As the title states, under no throttle my 1990 454SS 127K runs like it has a lumpy cam, but under throttle it runs OK. Also has a gas like, but not pure gas odor. Does it have something to do with anything vacuum related or is there an idle adjustment that worked its' way loose or broke?

 

[spistols]

I tried the EGR valve and thought this fixed it, but after a week, it started doing the same thing again.

 

[magimerlin]

When was the last time you did plugs? Atleast check a couple of them and see what they look like...

sent from what use to be a great country...

 

[spistols]

Did plugs about 5,000 miles ago. Again, this problem only happens at idle. Upon acceleration, no hesitation or issues.