Shakes when letting off gas at higher speeds

[volleybiggs]

I have a 94 legacy. Recently about 5% of time when I let off the gas
the engine will shake pretty badly. I dont get right back into the gas
I let it coast a few seconds and then back into the gas and it is
fine. It doesnt do this all the time only a few times a week.
I think I need to replace my EGR valve for another problem with
loseing power. I pull over when I feel I am loseing power it runs
rough for a min and then it is fine and I can drive it no prob,
Any ideas on these two probs?

 

[1 Lucky Texan]

I have a 94 legacy. Recently about 5% of time when I let off the gas
the engine will shake pretty badly. I dont get right back into the gas
I let it coast a few seconds and then back into the gas and it is
fine. It doesnt do this all the time only a few times a week.
 I think I need to replace my EGR valve for another  problem with
loseing power. I pull over when I feel I am loseing power it runs
rough for a min and then it is fine and I can drive it no prob,
Any ideas on these two probs?

Does it idle smoothly? I'm wondering if at that age your car could use
a throttlebody cleaning. I think that can clear up some problems with
the IACV which meters air when the throttle is closed. Do you get a
check engine light?
(saw your other post, I'll certainly investigatemy EGR valve)

 

[Yousuf Khan]

I have a 94 legacy. Recently about 5% of time when I let off the gas
the engine will shake pretty badly. I dont get right back into the gas
I let it coast a few seconds and then back into the gas and it is
fine. It doesnt do this all the time only a few times a week.
I think I need to replace my EGR valve for another problem with
loseing power. I pull over when I feel I am loseing power it runs
rough for a min and then it is fine and I can drive it no prob,
Any ideas on these two probs?

It is possible that an engine mount point is broken? A decelerating
engine would apply pressure on a forward mount point, but that mount
point may not be under too much pressure when accelerating.

Yousuf Khan

 

[volleybiggs]

All those are great ideas. I will have a look at the ideas. It does
idle smooth always and it only loses power very seldom but when it
does and I pull over it runs rough but then straightens out.
Thanks for the ideas!