What's your MAP values at idle with XFI?

[Chuck Leeper]

Probably been asked/answered, but:
What's it do in open loop/idle??

 

[norbs]

Ya and whats the a/f it stumbles and surges at?

 

[norbs]

Ttt

 

[turbojimmy]

Otto - thanks for the offer. I could've driven it there, and would have, but I was camping....in the rain....with the Cub Scouts. Doesn't get much worse than that.

I'm back, though, and can answer the questions:

Target A/F is 12.6. If I change the VE table to get there, it will go there momentarily and then begin to hunt. It will almost stall, but doesn't, A/F gets to the target, it tries to stall again, etc. and so on.

I haven't tried open loop idle. I can see what happens if I change the closed loop parameters to keep it in open loop during idle.

The o2 sensor is new w/ the XFI kit, but that doesn't mean it isn't bad. The open loop idle quality should tell me whether that's the problem, right?

Thanks all!

Jim

 

[turbojimmy]

Ok - if I let it idle in closed loop the A/F goes to 9.00 from the 10.25 it's at in closed loop. Crazy.

I may steal my brother's Translator+ and MAF to see how it runs with a stock-ish arrangement.

Jim

 

[ijames]

Haven't done the test personally but with a speed density system I don't think a vacuum leak makes it run lean (so long as the leak isn't in the map connections), it has the same effect as cracking the throttle open a bit. The idle speed will go up and then the ecm will close the iac to get the speed back down, but the afr won't change unless you move to a different commanded afr in the map-rpm table.

 

[turbojimmy]

Haven't done the test personally but with a speed density system I don't think a vacuum leak makes it run lean (so long as the leak isn't in the map connections), it has the same effect as cracking the throttle open a bit. The idle speed will go up and then the ecm will close the iac to get the speed back down, but the afr won't change unless you move to a different commanded afr in the map-rpm table.

Thanks, and you're right. There's something still not right with my setup, though, because even with a huge vacuum leak the IAC wouldn't go to zero.

Here's some more observations for the gurus to mull over:

All of my whining to date has been with the car in park. When I drop the car into gear, the A/F gets better but still not to target. With the car in gear, I can tweak the VE table to get to the target A/F and still have a decent idle and snap (actually it's now VERY snappy off the line). As soon as I put it back in park, it goes back to the really-rich mode.

It still can't control the idle correctly. I have the throttle blade closed almost all the way. Target IAC is 30, but it's idling at 1100 which is well above the 850 it's set at. It knows this because I can see the bubble on the chart, but the target IAC doesn't change. Conversely, if I do close the throttle blade all the way, the target IAC changes to the 50s but the idle is still too high. When I drop it in gear, it can control the idle.

So do I just have to live with a high idle and 9-10:1 AFR in park? I wouldn't think so.

Another odd thing is it says my boost DC is 100%. I don't know why it thinks this, but could it be fattening the fuel mixture because of this?

The last log I posted was just revving it in idle. This time I did some logging while driving around. It's rich at all times other than in gear, at idle which is where I made the VE table changes. I'm going to change the VE table across the board and see what happens......

Jim

 

[turbojimmy]

So I took 5 'units' away from the entire VE table. The car runs much closer to the target A/F now when I'm on the throttle. I can see A/F jump up then correct when my second fuel pump kicks in (using Aux #2) so at least I know that's working.

Still, the A/F in park and the idle speed in park and in drive are a mystery. It's still idling at 1000 RPM and the IAC target is up in the 40s-50s so it has plenty of room to close, but it's not.

Jim

 

[norbs]

Whats the alternator volts showing on the xfi??????????

 

[turbojimmy]

Whats the alternator volts showing on the xfi??????????

Between 13.0 and 13.6 on my latest log.

Jim

 

[Blazer406]

After looking a few minutes at your datalog..... your TPS scaling is way off..... it thinks you are at 16-18% throttle.... at idle (as I understood it... this log was supposed to be at idle....) ...... this could be a big part of your problem...... I think the XFI does have an "idle" part of the programming.... but I think this will all be screwed up if it thinks you have the throttle held a 16-18 % open all the time....

Still looking..... but HTH

edit: You need to add O2 correction to your dashboard.... so you can see how much it is correcting.... I might have missed it....but don't see 02 correction...

edit: from the electronic manual:

11.5.3 Max. TPS for Idle (%)

The "Max. TPS for Idle" field is used to set the threshold where the ECU no longer considers the engine to be idling. It is recommended to observe the TPS reading at an idle and setting this field to that number plus one. In other words, if your TPS reads 10% at an idle, set this value to 11. When the TPS percentage exceeds the value specified in this field, the IAC motor will be "locked" into the position specified in the throttle follower graph, and the Timing Trim graph will not be used.

With that said.... if the TPS is scaled properly.... I think it will be at 0% at idle..... and 100% at WOT.

 

[Chuck Leeper]

Haven't looked at the XFI for a while, but recall a procedure that requires you to check TPS v's key on/engine off/0 pedal. Then check @ WFO, and interpolate, and set several points between?? [Low, hi, and 7 in between, to get the tps calibration.]
If I'm correct, has this been done?

 

[turbojimmy]

Haven't looked at the XFI for a while, but recall a procedure that requires you to check TPS v's key on/engine off/0 pedal. Then check @ WFO, and interpolate, and set several points between?? [Low, hi, and 7 in between, to get the tps calibration.]
If I'm correct, has this been done?

I can check that out. I'm pretty sure when I checked it, it scaled okay. I have the maximum % for idle set at 1% above the idle. In the case where it's 15, I have the max idle at 16. Once it hits 17 it transitions out of idle (locks the IAC).

Thanks,
Jim

 

[Blazer406]

It might not be an issue... since you have yours adjusted to compensate..... however.... you must be loosing some resolution with 16% as your starting point....


We had an issue last year that the original calibration that came with our startup program.... the mV was a little low at 100%.... so when you went WOT.... the ECU thought you were over 100% throttle opening.... throwing a code.... anyway.... properly calibrated (thanks Cal for the over the phone support)... we got it right on the money........ 0% at idle.... 100% at WOT......

No more issues...

 

[HighPSI]

My pleasure Blazer406. Chuck is correct (pretty good memory for an "old fart" ) Have you verified timing and reviewed some of the other items I suggested?

 

[turbojimmy]

Have you verified timing and reviewed some of the other items I suggested?

Cal,

Thanks for your continued interest in this!

I checked the injector timing and have 1 ms open and 0 retard. What's interesting is that I have another calibration file from a board member that has very similar mods as I do (heads, intake and cam) except he has 83# injectors and I have 60/65# injectors. He had 1ms open and 20 ms retard. I don't know if it's because of the 83# injectors or not. When I tried his file out I put the retard to 0ms and changed the injector size to 65 (65 vs. 60 helps with the rich condition a little and doesn't seem to hurt otherwise).

This other file I have is tweaked for a 3.5 bar MAF, I have a 3 bar. The file was set to a 4 bar MAP and it looks like the VE table was manually scaled to the 3.5. I manually scaled it back to 3-bar values. The VE map on this other file is totally different than mine, but it doesn't seem to do me much good. This A/R table is leaner all across the board versus the file I started with, too. But, the car does the same thing - can't get to the target A/R in open or closed loop. If I tweak the cells at idle, in park, so that the target A/F can be maintained, it starts to hunt and eventually stalls. If I let it idle in park really rich (9.xx-10.xx:1) and drop it into gear, it can hover around the target A/F and seems to run decent otherwise. It gets a little leaner than the target at around 6-7 PSI and then gets right on target at higher boost levels. I can probably tune that lean condition out, tho.

It's the smokey, stinky idle in park that doesn't seem right. It never did that before so I figure that there has to be a way to tune around it.

Jim

 

[Chuck Leeper]

I..

"Chuck is correct (pretty good memory for an "old fart" ) "
resemble that remark!

 

[Otto J]

Jimmy do you still have an EGR valve hooked up?

If so check the egr functions in the XFI and make sure that
it is not commanding it at an idle.

THis happens on one of hte update and it puts
the EGR duty cycle at 100% in all boxes

 

[Otto J]

email a idle log and the gct and let me look at it.

 

[turbojimmy]

Jimmy do you still have an EGR valve hooked up?

If so check the egr functions in the XFI and make sure that
it is not commanding it at an idle.

THis happens on one of hte update and it puts
the EGR duty cycle at 100% in all boxes

I don't have an EGR. I'll e-mail you an idle .log file and a .gct file.

Thanks,
Jim