OK, so here's a new one...low idle, help me please!, also timing questions Options

[porsche735]

We just finished rebuilding our engine and it started right up the first time...

We set the timing at 27 degrees with both hoses removed at 3500 rpm. After the engine had warmed up and the aux air valve shut (even tested by plugging air inlet to valve), we tried to set the idle.

The idle is way too low, about 500 rpm max. The adjustment screw is making almost no difference. I played with the mixture screw on the ECU both directions (refresh my understanding, it is backwards, right? CCW is leaner, CW is richer). Adjusting this did not make a huge difference. I adjusted this to achieve highest rpm and richened one click (CW).

We cleaned out the air bypass hole to make sure it was not plugged.

We also played around with the TPS by shutting the butterfly valve all the way to make sure the ECU "thought" it was in idle mode.

I also have another question about advance. I have been told that we should see a total advance (with hoses on) of around 33-34 degrees. We checked our's after setting the 27 degrees the normal way, it was around 39 degrees. Does anyone have any specs on the mechanical advance and vacuum advance (retard as well, I guess)? My understanding is that at WOT that vacuum advance should be close to nil. We should basically only see the mechanical advance. However, we are seeing about 12 degrees advance due to the vacuum advance (39-27=12). Does this make sense?

We played with the advance all over the place and were not able to get the idle to go higher.

Please help me with these questions.... Your help is much appreciated.

Chris

[p914]

With the throttle body gasket, do you all make sure the drilled channel for the air bypass is covered?  Ours is.

Chris

That I have not checked. I discoed the smog pump on mine as in WA state any vehicle over 25 yrs old needs no emission inspection. I also use a K&N and do have the AAR hooked up. Although, I may try experimenting with it by plugging it also. PBAnders probably has the best experience along with Bleyseng that I am familiar with. I have tried a number of settings on mine before and after my mechanic tuned and adjusted things. The daily temperature and humidity do have effects and when a seasonal change sets in I usually adjust my system.. Are you working in a closed environment or an open garage?