Tunning question

Gravy · 05-28-2009

That's what it sounds like but my throttle almost doesn't change more than 1% the whole time while cruising. And i stay out of boost while it's happening, even if i step on it and put it in open loop, it still returns back to whatever state it was in. I.E. if it was early in the gear or if i'm ripping on it i'll get a good 11.5-12.1 AF when i get on it in the high setting. If i wait for i to switch, it likes to run 9.9-10.3 as it's set up now under WOT in the low setting.

Car has the following, to give you a full idea:

Stock 9b turbo's
450cc injectors
SAFC-II
GM MAF translator set at 0 for everything for now and using the SAFC only
MBC
3" turbo back with WB on the front bank
AEM WB 02 sensor
MMCD logging software used on palm
FPR set at 38psi no vacuum last i checked
Vacuum line reduction
Dejon 3/S intake splitter with Maf in blow though
Fuel Pump rewire
Battery relocated to the trunk
New plugs
Wires were new, but didn't make any difference so i went back to the after market ones i had on originally.

Oxygen sensors look fairly new, but i have never replaced them myself. But logs do show that both are cycling going back and forth on voltage.

Old plugs looked good, had about 2,500 miles on them and they were still ok, but while i had everything apart i was just gonna toss a new set in for $8. Using NGK part number 5553, i believe they are BKR6ES-11 thought of going platinum but no one can ever give me a good reason why to, copper seems more liked for boost, and i know the eclipse liked them much more than the plats.

Gap is set at .028, i get blow out at .032 but still get a miss slightly at .030 and .028 pulls hard under WOT. And it's running about 14lbs of boost atm and holds about 10 to red line.

niterydr · 05-29-2009

Quote:

Originally Posted by Gravy

That's what it sounds like but my throttle almost doesn't change more than 1% the whole time while cruising. And i stay out of boost while it's happening, even if i step on it and put it in open loop, it still returns back to whatever state it was in. I.E. if it was early in the gear or if i'm ripping on it i'll get a good 11.5-12.1 AF when i get on it in the high setting. If i wait for i to switch, it likes to run 9.9-10.3 as it's set up now under WOT in the low setting.

Car has the following, to give you a full idea:

Stock 9b turbo's
450cc injectors
SAFC-II
GM MAF translator set at 0 for everything for now and using the SAFC only
MBC
3" turbo back with WB on the front bank
AEM WB 02 sensor
MMCD logging software used on palm
FPR set at 38psi no vacuum last i checked
Vacuum line reduction
Dejon 3/S intake splitter with Maf in blow though
Fuel Pump rewire
Battery relocated to the trunk
New plugs
Wires were new, but didn't make any difference so i went back to the after market ones i had on originally.

Oxygen sensors look fairly new, but i have never replaced them myself. But logs do show that both are cycling going back and forth on voltage.

Old plugs looked good, had about 2,500 miles on them and they were still ok, but while i had everything apart i was just gonna toss a new set in for $8. Using NGK part number 5553, i believe they are BKR6ES-11 thought of going platinum but no one can ever give me a good reason why to, copper seems more liked for boost, and i know the eclipse liked them much more than the plats.

Gap is set at .028, i get blow out at .032 but still get a miss slightly at .030 and .028 pulls hard under WOT. And it's running about 14lbs of boost atm and holds about 10 to red line.

What are your throttle settings for high and low for the s-afc? Is it configured correctly? When did the problem start to occur?

Gravy · 05-29-2009

Low is set at 35%, high at 50%. Have tried raising and lowering the throttle point on both high and low. Looks like everyone has an opinion on where to set it, and i've found this works well for me, anything under 35% throttle is normally out of boost, or low boost, and runs the afr good for how i drive. Anything over 50% throttle i start seeing a good amount of boost, and anything inbetween the low and the high has a varying amount of boost.

The car has always had this switching problem since i got it. I would notice after getting up to 55mph i couldn't get on the throttle unless i waited a little bit, than i could give it hell when i first got it. After getting the wideband it was much more clear as to why i couldn't do that. But not why it was happening.

The car also does it at idle every once in a blue moon. It doesn't happen when fans turn on or off, or change with the voltage coming out of the alternator either. It's got a mind of it's own as far as i can tell. Speedo has been off since i got the car, i just havn't got around to trying to replace the speed sensor, i just drive to the corrected speed.

niterydr · 05-29-2009

Quote:

Originally Posted by Gravy

Low is set at 35%, high at 50%. Have tried raising and lowering the throttle point on both high and low. Looks like everyone has an opinion on where to set it, and i've found this works well for me, anything under 35% throttle is normally out of boost, or low boost, and runs the afr good for how i drive. Anything over 50% throttle i start seeing a good amount of boost, and anything inbetween the low and the high has a varying amount of boost.

The car has always had this switching problem since i got it. I would notice after getting up to 55mph i couldn't get on the throttle unless i waited a little bit, than i could give it hell when i first got it. After getting the wideband it was much more clear as to why i couldn't do that. But not why it was happening.

The car also does it at idle every once in a blue moon. It doesn't happen when fans turn on or off, or change with the voltage coming out of the alternator either. It's got a mind of it's own as far as i can tell. Speedo has been off since i got the car, i just havn't got around to trying to replace the speed sensor, i just drive to the corrected speed.

Sounds like an internal pcm issue if all the sensors are correct and wiring is good (and no aftermarket stuff is mucking it up). Can you swap out a stock ecm with someone to test?

Gravy · 05-29-2009

I can see if anyone has a spare i can borrow. I'll post up on the local 3/s forum. But i have had my caps replaced before they went bad, and i don't imagine them going bad already again. Still does it now, but runs much better than it has in the past.

niterydr · 05-30-2009

Quote:

Originally Posted by Gravy

I can see if anyone has a spare i can borrow. I'll post up on the local 3/s forum. But i have had my caps replaced before they went bad, and i don't imagine them going bad already again. Still does it now, but runs much better than it has in the past.

If the injector drivers or something else in the ecu was damaged from the leaking caps, that could be causing the issue.

Gravy · 05-30-2009

The rear 02 sensor is almost always reading .02v or .94-.95 if i remember correctly, and nothing else. Checking up on them at work to see if one can be gotten, otherwise i'll end up going to the dealership to find it there probably. Not sure of any stores that carry it locally in stock.

Also took my intake off last night and was followed by the following words, "Holly blown turbo batman". Looks like the rear turbo's oil seal may have gone, and if it's going out the exhaust as well(which i see no smoke from) it could cause some issues with the 02 sensor. But my intake around the sensor has a nice trail of oil on the bottom of it, going to use some Mas cleaning spray to clean off the sensors in the intake. And i may be in search of a 13g or a stock 9b turbo to replace it. But i figure if it has to come out, may as well upgrade.