I have been logging with Moates software and compiling it with VePhd. After burning a few chips and logging more I have reached a point where some of my VE table plots are at 100 in TC. I had changed my TPS PE points to 75% to prevent it from going into PE but now I am afraid to go any further so I don't tear anything up. I have probably been no higher than 4800 RPM and maybe 65-70% throttle. It is hard to get a broad range of RPM/MAP cells because the car accelerates pretty quickly up some smaller hills so I don't have a chance to roll the throttle easily and get into several points. I have been starting out in third gear a couple of times to seee what range that will get me into. When do I start using PE again. I disabled my FMU because I was told it was a "crutch for undersized injectors" so I went from 30 to 42 Lb inj. car idles good except for a flare up on startup but then it comes back down. Any suggestions?

 

Lower your injector constant and then retune your VE curve. This will basically tell the ECM to globally use larger injector pulse widths. Thus, all of the VE values will come down.

Tim

 

What?.

He's tuning without PE so ya he'll peg the VE table trying to fuel it all thru there.

I'd suggest backing way up and just revisit what he's got.

Add 5 or so % to the normal PE TPS enable and tune the tables with that, and then work on the WOT stuff.

You can set the TPS PE to 100%, and then tune that way, but all the AE stuff can get real confusing.

Personnally I synch the PE to the TCC or toward how I'd be shifting with a manual for peak perforamce.

Setting th PE high just gets you further into the tables easier, it's not meant as a means to try and tune the entire table.

Least in my methology.

On the flair, at start up, try SLIGHTLY reducing the very low rpm range of high K/Pa values. As an engine starts their is little to no actual intake vacuum so it reads in a very different end of the table then you would expect.

 

His VE table is maxed at 100% and he wants/needs to increase some of those points even more. In order to get more scalability out of this table (i.e. globally decrease the table so there is room for growth) just decrease the injector constant and then retune the VE tables. I know that this works because I have done it. Decreasing the injector constant increases the pulse width thereby supplying more fuel. The ECM will see this as a rich condition and decrease the BLMs. The VE table can then be readjusted by moving the values down. Thus, values at 100% will now be lower than 100% allowing room for growth.

Plus - he's not trying to tune PE AFR via the VE table. He's just trying to get his BLMs at 128 (14.7). Once they are there then he'll turn PE back on.

It's a moot point anyhow. He needs an ECM for a boosted application. The 749 should cover that one

Tim

 

Isn't the idle supposed to flare on startup? I thought the crank, fire, flare to 1500 then settle to idle was normal. Another way to fix that would be to decrease the IAC park position. IAC steps vs coolant is a second place to look, after you try decreasing the park position. I still don't know why you'd want to eliminate the flare, though...

 

I would like to try the 749 ECM although I just made the switch to the 730 so I would like to get it figured out first. One more thing, should I only be logging the acceleration and not the deceleration. I have been running my whole logged file through VePhd with all the accel. and decels. in there and retuning with the new BLM chart. So does that mean I am probably getting some invalid data from the engine decelerating or is that effecting anything. Seems on the decel it would have high vac. but show lean values and throw off my averages. Also, is the IAC park position a commanded position the IAC will remain in no matter what, at that set RPM. I know this has probably been covered before but I but I still don't comprehend the IAC counts and what they stand for as far as the IAC goes. I know it is a vacuum leak but what are the counts? And why can't one run without it. What would an IAC be equivalent to in a carbed setup, idle mixture?

 

IAC is a stepper motor controlled vacuum leak on the other side of the throttle valves. It lets the right amount of air into the motor in order to meet a commanded idle RPM. Also, upon startup (maybe shut down?) the IAC goes to a "park" position. In the case of my car, that was 160 steps stock. Since you generally start a fuel injected car with your foot off the throttle, this is what supplies the crank and initial running air. If this park position is large, assuming you have enough fuel, it will rev up more at startup, before settling to an idle. Note - I haven't tested this on my car, it's only my theory on the functionality.

Without the IAC, you'd have to jimmy open the throttle valves to have an idle that won't stall the car out. And that idle will likely be too high in some situations. Trust me, IAC is a good thing.

 

[QUOTE]Originally posted by Grumpy
Add 5 or so % to the normal PE TPS enable and tune the tables with that, and then work on the WOT stuff.
You can set the TPS PE to 100%, and then tune that way, but all the AE stuff can get real confusing.
Personnally I synch the PE to the TCC or toward how I'd be shifting with a manual for peak perforamce.
Setting th PE high just gets you further into the tables easier, it's not meant as a means to try and tune the entire table.



If I only add 5% or so to my stock TPS to PE settings then the BLM's lock onto 128 very early and I don't have anything to go by. Or do you mean add 5 more % to the 75% I am already at. I have several points in the middle of my chart at 99%. How are some of the other boosted applications on this forum tuning their cars with the 7730?

 

You don't have many options here if you are already close to or at 100% on the VE tables ...

1) Bigger injectors
2) Greater Fuel Pressure
3) Lower the injector constant
4) Use an FMU
5) Carrol Supercharging injector plate

Take your pick or use a combination of the above. You need MORE fuel in order to lower the VE table down so that you have more room for growth.

Tim

 

I really think the 42lb inj. shoud be more than adequate and I am running 47 psi fp. I hate to start all over on my VE chart so if I lower the inj. constant by a certain percentage do you think I could lower my current VE chart by the same percentage or does it not work that way? What is the max you have set your TPS% to PE when tuning for part throttle?