TimT thanks for the explanation. There really is no zero setting in the system. You can only tune around where it falls on the V/E table. This can vary greatly depending on how much if any blend you are using. I suppose you could do a 100% blend at 1000 rpm
I don't really have an idle problem I am working on fine tuning the startup and warmup maps and I am getting close to haveing a stable cold idle. It still idles 200 rpm slower than when warm but it idles without me holding the throttle open. Will post fuel maps when I have it just a bit better. I am also trying to get the V/E table to at least have an area of 0 settings. I now have the center section with all Zeros. I still have to bump up the fuel at the top and the bottom.
Mine is not quite stock at 3.4 and 273 rear wheels I have 34 lb injectors. Side effect poor response at very short pulse times.
I think perhaps other systems might make more sense when it comes to tuning. Would prefer the zero idle setting with a V/E table that adds from there.

I got to thinking about the cold idle issue in these PMO setups. In a stock Motronic system cold idle is achieved by dropping AFR into the 10.0 to 11.0 range at initial start but the motronic also has a IdleControlValve and it also opens this valve to allow extra air to bypass the throttle plate and thus increase base idle speed.

So, what if you introduced a controlled air leak at the manifold after the throttle plates? Sort of have a port on each manifold that allows a small, given amount of extra air into the system at cold start, this should allow idle speed to come up in proportion to the amount on air allowed to leak in, once you have the right size port to achieve higher idle you could simply route the port to a solenoid that is turned on only during cold start.

A simple test would be to find a port that could introduce an air leak and while in cold start simply allow some false air into the manifold and see what effect it has on idle speed. And since target AFR is always being maintained because of the MAP sensor the AFR should compensate by throwing more fuel in as the air leak is introduced.

Just an idea, am I way off base?

I have a WideBandO2 recording system in my Motronic 3.2L car and here is what Cold start looks like for the 3.2L this info will give you the general target AFR range to achieve a nice cold start:

http://forums.pelicanparts.com/uploa...1232463189.jpg

Notice how rich we run below CHT of 90F you really need very rich AFR below 90F, this was a 40F day and the AFR starts at 10.6 or so then rises quickly as CHT approaches 90F then after 90F, AFR rises more slowly till it reaches the 14.0 at CHT 180F. This is how a nice cold start behaves in the stock 3.2L Motronic.

Dang now why didn't I think of that :p

What really should be the target A/F. I have mine set for a target of 13.5 around idle, then tapering down to 12.5 for WOT. Seems kind of rich but if I go much leaner I get a terrible stall just off idle and the acceleration enrichment doesn't help. Trog what do you have for a A/F map.

As I said I've done tons of chip burning and tuning in the stock 3.2L and once warm your target idle AFR should be 14.2.

Then for WOT you should be in the 12.8 to 13.0 range, 12.5 is to rich for these air cooled engines.

But the real trick is the ignition advance, at WOT I run 30deg advance with AFR 12.9, do not push past 30deg, these cars will detonate! I suggest you set the advance about 25deg for starters then dial in the AFR across the RPM range, once you have it set bump the advance a degree or 2 at a time but always recheck the AFR. Keep in mind the stock motronic DOES NOT have a knock sensor, if your EFI system supports a knock sensor you may be able to push advance even further so long as the EFI system can dial back advance if knock is detected.

Bottom line is most Power comes from ignition advance once the AFR is dialed in.

The other area that is most important is the part throttle maps for fuel and ignition, it is these maps that give you throttle response. In the PT maps you want to shoot for 14.2 AFR at light load say under 40% load conditions. But as load increases above 40% you need to start adding fuel so that at hi-load (but not WOT) you should be in the 13.2AFR range. This is so as you demand response (step on the gas deep) you want AFR to richen from 14.2 to 13.2 quickly. Also PT ignition maps are very important and you need to advance ignition as well. It's not uncommon to see ignition advance as much as 45 degrees in the 3500-4500 rpm range at moderate load (50%). This is the real trick to getting that neck snapping throttle response. In my opinion the PT maps are the most important to get tuned as these are the seat of the pants you really feel. Your car is rarely ever in WOT mode so don't spend to much time on WOT.

As for your stall coming off idle not sure why that is: but could be your PT maps at lo-load do not match your idle map. Not sure how your EFI system works. But the idea is that as you come off idle you need things not to change to much. My guess is something is changing a lot coming off idle, like the AFR or the ignition timing. The idle ignition timing should be set to about 0deg maybe -5deg (0-5deg ATDC).

I'm using 26lb/hr injectors. They appear to be adequately sized for my application.

Here's my AFR Set-point table over all loads. My MAP reading at idle is about 55kPa(a):

http://forums.pelicanparts.com/uploa...1232468267.jpg

With a TOG=13.2 and and IOT= -3.25, this is what my current VE Table looks like. Note that I have to add fuel at WOT, and dump fuel at idle and low loads to get my AFR on target. If i reduce the IOT any more, then I hit the minimum injector on-time limit of 1.5ms:

http://forums.pelicanparts.com/uploa...1232468842.jpg

Trog,

I was looking at your AFR table, I think the 14.0 at low loads is just fine but the 12.6 at high loads is to rich for max power from what I've seen in the stock 3.2L. I found max power to be in the 12.8 to 13.0 range (I'm set at 13.0 at WOT). Also I would not jump the AFR so quickly, I'd start moving richer at 50 or 60% load and gradually head for the 13.0 by the time you get to 90% or so. This is how the stock tables do it. Hope that makes sense.

First it looks like on you A/F you have not increased the fuel in the 5500 - 7000 WOT region. I would think that would be where it is needed most.

I have to do a test drive of my current configuration before I do a post of the maps. So I know if it works or not. Currently I have it set for an idle MAP of around 55 kpa and the V/E table is zeros from about 40 - 65 kpa then I am progressivly adding fuel both above and below to richen things up in those areas.

My plan is turn the TPS/MAP blend to very high say 80% below 3000-4000rpm. This then place the indicated MAP at probably 30kpa. I will then adjust my UAP(TOG) to 12.888 and set my POT (IOT) to 0 or what ever is needed to place my adjusted pulse width to match what it is now at 55 kpa. This should then take care of the low MAP reading going lean or below the minimum injector on time. Not sure what will happen when the vacuum actually goes in that range. Should just use whatever the lowest reading is. Perhaps use the deceleration to cut the fuel earlier. Anyhow going to give it a try and see what happens.

Also just for comparison purposes as I should really not be butting in on trogs thread other than we appear to haveing about the same issues. As far as engines go mine is not quite stock. 3.2-3.4 rebore with JE 10.5:1 pistons DC21 Cams and twin plug.
On the ignition timing I found that 30 degrees gave max power even with the twin plugging. I could go more and not get any detonation I just started to lose power.
I seem to get varying advice on the A/F ratios. Anywere from 12 to 14 so I can't come up with what is truely correct. Lean may be good for power but at what point is it hard on the engine. Richer may keep the engine cool but at what point is it too much. Perhaps we need to have a definitive A/F thread. Eventually information like that would wind up in the wiki.
My maps are 13.5 at idle and 12.5 WOT seems to me to be a bit rich but at 14 for idle I get a horrible stall coming off idle. The A/F may be different for ITBs than it is for stock.
If TimT is still reading what do you use for A/F ranges. I think these are question that both trog and I have.

I agree that ITBs may be different. But 13.5 at idle and 0-50% load is to rich and you will simply burn to much fuel for no reason. You should target 14.0 to 14.5, I run 14.2.

Now with regard to hi-load and WOT AFR this will vary from car to car, but somewhere between 12.5 and 13.2 seems to be the number, the only way to nail it down is dyno time, then whatever produces most power I'd add .1 or .2 extra fuel just to keep things cool.

One last very import thing in these cars is CHT it MUST be watched carefully! Does your EFI system allow you to back off timing if CHT rises? The stock Motronic system does this. I monitor CHTs in my setup and boy was it an eye opener to see how they behave. Normal range is in the 300-320F area but they climb VERY quickly at WOT near peak torque and the big surprise was how fast they climb if you lug these motors, like hi load at low RPM - like 5th gear at 2000RPM and then decide to hit WOT they start to climb into the near 400F range, when this happens something has to give and backing off timing is simply a good idea if you can do it. What I found is that if the engine fan is spinning slowly and you lug the engine you just don't have enough air flow to keep the cyls and heads cool. The CHTs are lowest when I drive in the 3000-4000RPM range so I tend to always run in this area for daily driving.

Well just went through 20 pages of search feature looking for A/F information. Only definitive thing I found was WOT of 12.5 is the number to have.

Differing advice
found 16-17:1 at cruise (seem very lean to me)
found 14.7:1 at cruise ( may be reasonable)
found 14 to 14.7:1 at idle (probably OK but I have terrible stall coming off idle)
This would then leave some form of transition from idle to expected 12.5 at WOT. For sake of argument lets assume we are not useing fuel to prevent knock. Where should we be at and any suggestions how to get rid of the off idle stall at higher A/F ratios. I am currently running around 13.5 at idle and cruise then progress quickly to 12.5. Not much in between.

The 14.7 number is most likely associated with cars running O2 sensor and in closed loop mode. Then let's leave the WOT AFR discussion aside for the time being.

So whats going on when you come off idle? can you tell us more, is anything changing in the maps? like does ignition timing change drastically in your idle to low load ignition maps in the 800-1200RPM range? same for your AFR does it change much?

Read this old post from one of the better 911 tuners around:
http://forums.pelicanparts.com/porsche-911-technical-forum/146093-carrera-3-2-performance-mystery-chips-long.html
You will find he quotes 13.0 AFR for max power at WOT

Perfect sense. AFR 14.0 at idle, gradually moving to AFR 12.8-13.0 at WOT.. piece of cake!

The ECU only allows for advance in timing on the basis of coolant temperature (CHT) to assist with cold starts. It does allow the timing to be retarded on MAT (not much use in the case you described)

You would think so, but with my TOG at 13.2ms, I had to back-off on the fuel at 5500 as it was running way too rich.

Yes but stay at 14.0 till about 40-50% load only after this do you start to enrich. You can play around with this more later when you have more road test time and fine tune further. The 14.0 will give you decent fuel economy up to about 50% load then after that you want performance.

Trog,

Can you post your ignition map(s), does the system only have one ignition advance map? Or does it have one for idle, one for PartThrottle, and one for WOT?