CARBURETION and your Large/Small port 16V 4AG

[firehawk]

Apolan Wrote:NoHachi mentioned that using the stock ecu in the limp home mode hinders the max potential by at least 20%. Does wireing up the map sensor like explained above (firehawk, Ben) improve on that? Im not quite sure how this 3d map works..

For a street driven car, using locked ignition advance in limp mode is certainly a bad idea and would make the car reluctant to start and probably quite annoying to drive in city. Faking the missing sensors using resistors as I described above would make the ignition work just like it does on a stock engine - with one exception, though. The IDL switch inside the throttle position sensor would still not be functional, so the ECU would never go to the idle/overrun "map" - this might create a need to raise the idle speed a bit and also cause some popping in the exhaust when engine braking.

Do the Dellorto carbs have ports for drawing manifold vacuum or would they also need the vacuum to be tapped directly from the manifold runners? My TRD manifold has threaded holes only to runners 1 and 4 so I've been thinking whether it would be possible to take the MAP vacuum signal from these two only and maybe use a small filter/restrictor in the hose before the MAP sensor to even out the "bumps" a bit. I'd rather not butcher the manifold by drilling additional holes to it.