7730 ARDC, AZTY, and other V6's

[TK]

I just back off the timing in that load/RPM area of the tables, but then I
run the EGR since it should snap shut at WOT. During cruise, I am torn on
the MPG issue. It can run more advance which should increase the MPG, but
the leaning of mixture forces the increase in fuel.

This is on an 85 2.8L MPFI running a 7730 using the 91 HEI/Mass eprom. (Not
DIS and SD). These engines like to ping very easily in the 3000-4000 RPM
range. The AL head engines are better I guess.

Terry Kelley


-----Original Message-----
From: Mike Pilkenton <mpilkent at ptw.com>
To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
Date: Monday, July 05, 1999 12:14 PM
Subject: Re: 7730 ARDC, AZTY, and other V6's


>This is true.  I have heard from amny experts that when you disable the EGR
>you must then increase the A/F mixture some to reduce pinging/detonation.
>Not sure if this is normal for the ECM to do when the EGR function is off
>anyway or if some additional programming of the tables is required??
>
>Mike Pilkenton
>-----Original Message-----
>From: TK <terryk at foothill.net>
>To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
>Date: Monday, July 05, 1999 11:29 AM
>Subject: Re: 7730 ARDC, AZTY, and other V6's
>
>
>>EGR reduces ping too. Noticeable at cruise at light to moderate loads. The
>>V6 2.8/3.1L really demonstrate this.
>>
>>Terry
>>-----Original Message-----
>>From: rr <RRauscher at nni.com>
>>To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
>>Date: Monday, July 05, 1999 11:19 AM
>>Subject: Re: 7730 ARDC, AZTY, and other V6's
>>
>>
>>>Doug wrote:
>>>
>>><snipped good info>
>>>>easier it becomes like a puzzle.   I did find the min. temp for the EGR.
>>I
>>>>will set this to $FF.  That is the best way to disable it, because it
>>>>causes the calculations to work correctly.  Right now I just blocked the
>>>>EGR tube  and the computer was happy (no light).  The address in mine
was
>>>>$8E8B = 66c = 154F,  if I am right.....  I am surprised that not many
>>>>people realize what a performance and gas milage killer the EGR is.
>There
>>>>is no benefit of it that I can tell.
>>>
>>>Well, the benefit is lower NOX emissions. But, I was surprised at the
>>>performance increase. Was totally unexpected, and started myself
>>>thinking, which can be dangerous in it's own right. The egr ducks-out
>>>with the smallest amount of acceleration, so why the performance
>>>difference?
>>>
>>>Maybe it has to do with lowering the heat input to the engine. The
>>>intake
>>>tract will run cooler, so you should be able to get a cooler charge. The
>>>other will be how dirty the throttle body gets, or lack thereof. These
>>>things get filthy, causing all kinds of problems. The only thing adding
>>>grime is the egr, and wow, does it! (ever clean a TB, it's looks like
>>>the
>>>inside of a sewer pipe {don't ask})
>>>
>>>Maybe timing lag, as the SA is lag filtered with the egr?
>>>
>>>>     OK I just looked at the AZTY.  Look at address $4494 and following
>>>>(which is actually $C494).  It looks like the coolant is address $4D (in
>>>>mine its $4B) and that is compared to $8EEF.  That should be the min EGR
>>>
>>>Dead on Doug <g>, I changed the $8EEF to 0xff, and the egr doesn't come
>>>on. Also disconnected the wires to it, and checked for trouble codes,
>>>none. Looking good...
>>>
>>>>temp.  Also AZTY is the same on the EGR bit which is $2B,#10.  I think
>>that
>>>>is the EGR on/off.  Look at this and see if I am right.  All or some of
>>>>this could be wrong.  hehehe...............Anyway all of my notes are
>hand
>>>>written on the printout.  maybe I could copy them later on and then scan
>>or
>>>>mail them to you all somehow....if I can be of help let me
>>>>know................doug
>>>
>>>
>>>BobR.
>>>
>>>--
>>>
>>>
>>>
>>
>
>