Engine swap and car idels rough

[chrisLB]

So I did the swap and the car run smooth at high idel but as soon as it wants to drop to a lower idel it starts to stall and the idel jumps back up and slowly comes down again... I swaped a 2000 L67 in to my 98 gtp I used the 98 throttle body and 98 injectors and the engine ran great before install... My only idea is I think where the egr plugs into the headers looks like there's a big gap... Will that cause the rough idel problems? Thanks

[Rico]

If there's a gap in the tube that goes from the UIM to the EGR then this may cause a severe vacuum leak.

[machinegunsquid]

On the L67 it goes from the rear mani to the EGR, then from the EGR to the LIM.

Yes, if there is a big gap, that can cause an issue. If you feel exhaust coming out around it, then you need to seal it up better, or delete it.

[Rico]

Actually same for the L36, EGR to the LIM; not UIM. Sometimes I let my fingers do the talking.
Thanks machine.

[chrisLB]

I Spent a lot of time checking for leaks and found it was the throttle body was leaking from the gasket.... Runs like a top now

[chrisLB]

I Spent a lot of time checking for leaks and found it was the throttle body was leaking from the gasket.... Runs like a top now<br>