eyeoutthere

Hi all. I have a 5.7L TBI and automatic tranny with 115k miles. It is in a 1993 Chevy van but I figure you guys will be able to help me just the same.

When I am cruising on the highway, the van will shudder in-between ½ and ¾ throttle. It feels like the engine is missing but I am not certain that is where the shaking is coming from.

It only happens when the car is hot and in-between ½ and ¾ throttle (It goes away if I give it more or less gas).
It does the same thing if I take it out of OD but it is less violent.

I replaced the TPS and nothing changed.
I tried electronically unplugging the MAP sensor but the problem was still there.
I checked the temp sensor: resistance looks OK (320 ohms when engine is hot) and connector looks to be in good shape.

Anything else I can check? Any ideas?

Thanks!

chevy_dude97

TCC? does it some times slam down shifting at stop signs?

eyeoutthere

I think it is the TC. There doesn't appear to be any problems with shifting otherwise.

According to this, the van has a 4l60e:
http://www.justanswer.com/uploads/Me...91229_trns.jpg

According to this, what I am experiencing is "TC Shutter" (see #25):
http://www.gmtruckhq.com/?q=node/93

I found resources that recommended "Dr. Tranny Instant Shudder Fixx" which helped but did not fix it entirely:
http://www.lubegard.com/~/C-230/Dr.+...t+Shudder+Fixx


I don't want to put anymore money into this van so what cheap/free fixes can I do in the interim?
I would assume that shuttering is bad for what is left of the clutches. Since this only happens when the TC is locked, would it be better to disconnect the TC lockup wire?
Are there any disadvantages to not locking the TC other than decreased fuel economy?

Thanks!

Stevolwevol

Does the shudder happen in any gear, or only on the hway?

ray396

Check or disconnect, EGR . then drive and see if it is better.