If you have a big leak the IAC will be bottomed out and the engine idle speed will increase above the target.
What's your MAP values at idle with XFI?
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If you have a big leak the IAC will be bottomed out and the engine idle speed will increase above the target.
It should idle in closed loop unless he has the O2 sensor too close to ambient air. Like a fender dump or short down pipe.
I respectfully disagree.
I had my buddies T6 Iroc with an XFI idling decent in closed loop......someone suggested I idle in open loop.......so I changed it....played around with it.....got it to idle nice..... even with 160# injectors....the next morning....it was 10-15 degrees cooler......I had to go to the starting line with the laptop and bump the idle cells in the ve table like 5 numbers to get it to even stay running.....needless to say....I never had that problem with it in closed loop.....
Just my experience....
Holy cow your still alive!!!
How was spending a week in Canada tuning for the Canooks?
Worse yet how was spending one day with John Shmidt on the Riv?
IMHO......don't worry so much about green, yellow, or red....at this point...
When idling......what kPa is it?
When you goose it.....does the kPa's drop?.....
If so....this is a different portion of the table....and you should be able to richen accordingly.....
If you do adjust the idle cells down until the correction nears 0 at idle........you might can look in the fuel tables......there is one called..... AE vs TPS rate of change.......kind of like an accelerator pump is on a carb...... you might tweak that to give some extra fuel when you goose it....to keep it from going dead......
FWIW.....the ve table needs to be idling near the bottom.... but not directly on the bottom left of the table..... it needs cells all around the cell it usually idles in.....if not.....your table needs to be re-scaled.......that is the only way to be able to really tune the idle portion of the table.....
HTH
Holy cow your still alive!!!
How was spending a week in Canada tuning for the Canooks?
Worse yet how was spending one day with John Shmidt on the Riv?
Canada was REAL cold, eh! I spent a week there and tuned on a couple of cars in Calgary then flew over to Vancouver to tweak on a few cars. I was only home for 8 hours, then flew to Ohio to play with the Riviera. We sorted a lot of things out and I am very happy with the progress we are making
If you really think it's a vacuum leak...
1. Why not trying using an air compressor to pressure up the whole intake system while the car is off? Much easier to find air leaks that way I think. Do a search, there's some how-to threads floating about. I found a few vac leaks that way.
2. One leak I found that way was my throttle shaft seals, which leaked a bunch only when the throttle was open. When at idle with the throttle closed they sealed up just fine. The leak you describe, only hearing it when cruising but not at idle, could be the same. I never would have found it with pressuring up the intake with the car off, and working the throttle by hand.
John
1. Why not trying using an air compressor to pressure up the whole intake system while the car is off? Much easier to find air leaks that way I think. Do a search, there's some how-to threads floating about. I found a few vac leaks that way.
2. One leak I found that way was my throttle shaft seals, which leaked a bunch only when the throttle was open. When at idle with the throttle closed they sealed up just fine. The leak you describe, only hearing it when cruising but not at idle, could be the same. I never would have found it with pressuring up the intake with the car off, and working the throttle by hand.
John
turbojimmy
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- May 26, 2001
I've been too lazy to do that. My brother has done it, though. Just yank the valve covers and pull the rockers and that seals everything up. It might come to that.
I've been reluctant at this point to make any permanent changes to the VE tables since I feel like I'd be correcting around some other problem. The car ran great when I first installed the system.
At this point however, I think Blazer you are right: if I get it running decent by tweaking the software that might give me enough information to figure out what the problem is.
The IAC isn't bottoming out, but close to it. Target is 26 or so at idle; it was well below that so I closed the throttle blade. Doing that got the IAC up to target which is what had me looking for a vacuum leak. I haven't goofed around with it since I found the EGR and vacuum block leaks. I might be able to crack the throttle back open the way it was now.
kPa is in the low 40s at idle - it's showing -8.4 to -8.8 PSIA on the dashboard.
At idle the bubble is in the bottom left side of the VE table, but not the very bottom. It does have cells around it. I can definitely tweak those cells to get the car into the right A/F range. I need to drop them by 20% to do it but it can be done.
Thanks all for your ideas. I'll sort it out one of these days.
Jim
turbojimmy
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- May 26, 2001
Right. That's why the first thing I'm going to do is hook the smoke machine up to it. It doesn't make sense but it's all I can think of. I really didn't change anything vacuum related. It all started when I moved the MAP (which I guess is vacuum related, but I checked my work and didn't cause any leaks).
I'll tinker with it tomorrow and/or Friday night. Going camping with the cub scouts this weekend so I won't have time to mess with it too much
I still question whether I'd be too rich or too lean with a vacuum leak. I know with the MAF it would show up lean in the O2s but mine is showing up very rich in the O2s. So am I looking for a vacuum leak?
Jim
turbojimmy
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- May 26, 2001
Here's a log file. Haven't hooked up the smoke machine yet.
Right click, save as.
http://www.turbojimmy.com/idle_100308-1.jpg
Change the .jpg extension to .log so that CCOM can see it. Had to store as .jpg because of my stupid hosting company.
You can see the stupid rich idle, but it's also way rich off idle. If I drop the VE table down to where the A/F is acceptable the car barely runs - idle hunts and it tries to stall and catches itself.
Jim
Right click, save as.
http://www.turbojimmy.com/idle_100308-1.jpg
Change the .jpg extension to .log so that CCOM can see it. Had to store as .jpg because of my stupid hosting company.
You can see the stupid rich idle, but it's also way rich off idle. If I drop the VE table down to where the A/F is acceptable the car barely runs - idle hunts and it tries to stall and catches itself.
Jim
turbojimmy
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- Joined
- May 26, 2001
Well the car passed the smoke test. If there's any vacuum leaks they're very small. I pumped A LOT of smoke into it with the DynoFog II and nothing came out.
So something is just plain f'd up with it.
Off to change out of my exhaust-smelling clothes......
Jim
So something is just plain f'd up with it.
Off to change out of my exhaust-smelling clothes......
Jim
X 2
turbojimmy
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- May 26, 2001
The A/F table is fine - no need to mess with it. The XFI just can't get the A/F where it needs to be. It's not possible to rescale the VE table to get it to remove the 02 correction to meet the A/R values. At idle, for example, I need to drop the VE from the programmed value of 38 (which used to work, by the way) down to 24. When I do this, the idle picks up and the A/R comes up close to the target, but it can't maintain it. It starts to surge and sputter.
Since it worked when I first installed it, but doesn't now, I don't think it's in the tune. I think it's some sort of physical failure of something air/fuel related. The question is what? What would cause XFI to dump so much fuel into the mix that it then has to take it back out? I think the giveaway is that when you do force the VE values down to a reasonable A/R, it can't maintain it.
The smoke test is a pretty good indication that there's no vacuum leak, but if there were it would be lean anyway, right?
The vacuum line that goes to the FPR smelled like fuel, but I yanked it while it was running and nothing came out so I don't think it's drawing fuel into the vacuum line.
It sucks because the engine and trans are brand new and I can't drive the car. It makes me sick to think about it, actually. I'll probably just bring it to my dad's and store it until spring. I don't have the time or patience any more this year. Maybe I'll yank the XFI out of it in the spring and go old school.
Jim
Since it worked when I first installed it, but doesn't now, I don't think it's in the tune. I think it's some sort of physical failure of something air/fuel related. The question is what? What would cause XFI to dump so much fuel into the mix that it then has to take it back out? I think the giveaway is that when you do force the VE values down to a reasonable A/R, it can't maintain it.
The smoke test is a pretty good indication that there's no vacuum leak, but if there were it would be lean anyway, right?
The vacuum line that goes to the FPR smelled like fuel, but I yanked it while it was running and nothing came out so I don't think it's drawing fuel into the vacuum line.
It sucks because the engine and trans are brand new and I can't drive the car. It makes me sick to think about it, actually. I'll probably just bring it to my dad's and store it until spring. I don't have the time or patience any more this year. Maybe I'll yank the XFI out of it in the spring and go old school.
Jim
