Thewidowson

Since bought my 90 the intake manifold switchover has never worked.The plastic piece that connects the physical swithover to the intake manifold is broken.I removed the entire switchover. Now im wondering which position is open or closed.I would like the butterfly valves to be closed.If im standing on the driver side of the engine bay.
should this piece be moved to the passenger side to close the valves or the driver side?12v 2.8 btw.

Rusty Spokes

Those butterfly's did have a problem with the screws coming loose..be sure and "stake" and loctite them too.

The closed position is as this picture..the vacuum servo pulls the butterfly valves open.

I would just try and repair the original set up and find that plastic part. The variable intake system works well and I think you will have performance problems if you fix the assembly closed all the time or open all the time.

The part number for the broken part you need is, I think..078133159..it was used on all the 12v V6 engines..available at the bone yard or new.

Thewidowson

Thank you for your detailed response.I recently hollowed out my cats and did an egr delete,steel welded the open hole in the im. Replaced a rusted section of fuel line and put a new fuel filter on.It still had the original fuel filter!.At that time I removed the switchover. I had set the im for the longer runner position,thinking it was the short.I imagined that it pushed instead of pulled.Like you said it wasnt performing well.Once it hit 4100 rpm.Id get awesome induction noise and it would go.But up to that it was very lazy. But after looking at your picture I switched it to the short runner position and its flying now.Even after 4100 it seems to respond better than it did in the long runner position on the high end.But I dont know what im missing out because the switchover has never worked to begin with.Thanks for the response it has been helpful.Also for $95 I think ill leave it be for now.If it works it works.