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> OK, so here's a new one...low idle, help me please!, also timing questions
porsche735
post Sep 8 2003, 10:39 AM
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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
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Posts in this topic
porsche735   OK, so here's a new one...low idle   Sep 8 2003, 10:39 AM
Brad Roberts   Is it running on all 4 ?? I mean firing on all 4 ?...   Sep 8 2003, 10:44 AM
Bleyseng   Sounds like you have the vacuum/retard hoses hooke...   Sep 8 2003, 11:00 AM
porsche735   It's running on all 4. This is very odd. The...   Sep 8 2003, 11:26 AM
Brad Roberts   Did you wash the engine compartment with the press...   Sep 8 2003, 11:43 AM
porsche735   No, why? They don't work when filled with wat...   Sep 8 2003, 12:42 PM
p914   How long did you let the engine run before trying ...   Sep 8 2003, 12:46 PM
porsche735   It ran maybe 10 minutes. We did not run it hard a...   Sep 8 2003, 01:33 PM
redshift   As Dave said over on PBird, cam break-in @ 2000 rp...   Sep 8 2003, 02:13 PM
porsche735   It is just a top end rebuild including P&C. Howev...   Sep 8 2003, 02:18 PM
p914   I think a bit more time to warm up is needed. Let ...   Sep 8 2003, 02:21 PM
porsche735   It is not the temp of the engine. In general, the...   Sep 8 2003, 02:26 PM
redshift   I am wondering if we aren't on the wrong end l...   Sep 8 2003, 02:51 PM
porsche735   The parts are matched fine. The engine was workin...   Sep 8 2003, 03:04 PM
redshift   lol.. hang in there Chris. When it was running, ...   Sep 8 2003, 03:12 PM
porsche735   Unbelievably smooth, yes. We cced the heads and m...   Sep 8 2003, 03:19 PM
ChrisReale   Is the idle bad at all operating temps? Double ch...   Sep 8 2003, 03:30 PM
p914  

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