MavrikTA

iTrader: (27)

Hey guys. I could use a lil help here. I just got my PCM back from TSP with a new tune for my cam(MS3) and the car is running pretty good, but I am having some issues, that may or may not, be normal.
Necessary information: I am running an AEM wideband and a Fuel pressure guage. My fuel pressure never goes below 60PSI.
My biggest issue, is I want to make sure that my current lean condition is not something that I can address, before I see about retuning for it.

#1. I threw a code P0101 today, after having driven the car 50miles on the new tune. 50miles after that, I found a code P0102.
#2. I cleaned my MAF with electric cleaner and the car runs much better, but both codes are still present.
#3. My AFR has some odd dips and spikes when cruising. At times it will drop to 10.1 or spike at 17.1....this may be normal...Im not sure.
#4. I am still running too lean. My WOT AFR is 13-13.5, but it seems to be coming down as I put some more miles on the car....is this to be expected?
#5. Car searches for idle for 10sec or so, but overall idles really smooth@approx: 900RPM.
#6. I unplugged the MAF sensor with the car idling and the car stumbled, but then began idling just as good as before with a richer AFR.

SSL, just dont have alll the nifty tools and Im trying to be as descriptive as possible.
Thanks for any help!
Mav.

kenp

iTrader: (9)

I'm no expert but I'll try to answer some of your questions.

It isn't normal for AFR to swing from 10.1 to 17 at cruise. My AFR at cruise is very close to 14.7 and very stable.

Searching for idle is not normal, but common after a cam install. It indicates some aspects of the timing, cracker, follower, and some others may need tweaking.

As you drive your car and the Long Term Fuel Trims adjust based on STFT's, if LTFT's are positive, fuel will be added at WOT beyond that commanded. Might be why your WOT AFR Seems to be getting richer.

13 - 13.5 AFR @ WOT isn't all that bad. I run pretty good at 13/1.

When you unplug the MAF, you should set a code and your PCM should adapt the low octane timing table, which may be causing you to run richer.

I have no way of knowing what was done to tune your car or the method used. Some tuners adjust IFR, some adjust VE, and some adjust VE and MAF.

Most of us with the software try to get the VE close and then try to get the MAF close. As an amature at this tuning business, I have spent many many hours reading and asking questions and logging data and making adjustments to parameters and chart values to get a reasonable idle and good AFR.

Codes don't clear themselves, you have to do it.

Not sure but I think fuel pressusre is supposed to be a constant 58, so 60 on your gauge is no biggie.

Maybe you'll get lucky and someone who knows more than me will chime in.

vaticano

iTrader: (8)

my AFR will do the same thing when i plug in the maf trying to tune it. turns out the o2 sensors are'nt getting hot enough, because of the headers. my guess would be your cam has a lot of overlap cooling the front o2 sensors. have you taken any long trips to really heat up the exhaust/o2 sensors.

ZL1Killa

iTrader: (17)

somebody needs to tune that thing right

ncnumber8

iTrader: (1)

To me it sounds like your injectors are scaled improperly in relation to your fuel pressure which is what you get with a mail order tune. The higher fuel pressure is causing your motor to run rich and the MAF is working it *** off to try and correct it. But the maf can only respond so fast. The closer your tune is, the less the maf has to work and the smoother/better it will run. There is a spreadsheet floating around that helps you determine the values to plug in for the injector scaling. At crusing speed your AFR should be 14.6, but if it goes up to 17.0 while idling, I wouldn't worry about it because thats pretty normal for the size of cam you have.

Frost

iTrader: (45)

Not sure why the MAF is attributed to operation of CL control twice in this thread but...

You have a mail order tune and it's close but not right, this is how they are, there is no substitute for real tuning. Most "mail order tuners" don't even ask you what your rail pressure is...

edcmat-l1

iTrader: (10)

Sorry for the hijack, but MAFs do not correct A/F ratio. They meter airflow. Thats it. Its up to the computer itself, based on 02 feedback, to correct for A/F ratio deviations.

vaticano

iTrader: (8)

my bad

I'm in OL SD.

radkon

iTrader: (2)

Unless you clear the codes (with a scanner or disconnect the battery for 15 mins) they will remain for awhile.

Some dips and spikes are normal depending on the following.
At WOT (full throttle) your AFR should be close to 12.8 (10.1 is still WAY low)
If your car is using Dynamic fuel cutoff (DFCO) when you let off the throttle you may see lean spikes greater than 20:1 AFR this is normal.
If you are steady cruising, your AFR should be pretty close to a consistent 14.7

AFR of 13.5 is RICH not lean. Ideal is 14.7. Example of lean would be 15.5

VE table and RAF tables may need a bit of work to smooth this out.

The car will default to "Speed density" mode and use the VE tables to keep running. That stumble was the computer switching modes.