Michael Ozorowsky

iTrader: (1)

hey everyone. I got some tuning done exactly as above link stated, and car idles fine. However, when I put it in drive or reverse, car stalls. If I put it in neutral or park car idles fine. If I put it in reverse/drive, and push on gas car will keep running, and I can drive. Any thoughts? What do I check/what should I modify.

horist

any scan info you can post up? what changes have you made thus far? What do you idle at? stock cam I'm assuming?

Michael Ozorowsky

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Cam is a 230/234 591/598 on a 114 I am running felber racing "Big Uglies" Heads. From what I understand they are 2.02 intake 1.57 exhaust. Dunno what other specs you may needs. I can't wait to dyno maybe next weekend, but I'm curious, floored car for first time today and I know it still needs tuning, but didn't seem that fast. If you want me to run a scan horist, just tell me what to scan and I will GLADLY get you something by tomorrow.

horist

scan is good, just use the default parameters in the HPT Scanner ...

Have you already tried scaling the VE table for 400-1200 RPM down by say 70% of original? I scaled my down to about 65% and it helped the idle characteristics alot (236/242 on 112 LSA)

Michael Ozorowsky

iTrader: (1)

horist: What I did for idle VE was start scanner, drive around a little, (Through stop lights, etc.). and tune my VE like I usually do. Which is do a histogram scan, and then take my values, and modify so let's say at 1600rpm and .30g/sec my histogram shows 23, I would ADD 23 to that exact point, and it brings it down to around 0. I do this for ALL points, and then scale the table 2 or 3 times. Before heads/cam this tuning method worked GREAT for me. Just takes a while to get right.

Michael Ozorowsky

iTrader: (1)

horist, if you can email me your email (Michaelozorowsky@hotmail.com) I will go out get a scan tomorrow, and then send it over to you. Thanks.

horist

Mike at horist.com my email... i'll log on tonight and shoot you a mail . I would set the VE table back to stock for 400-1200, then scale it down to 70% of original for all of the load values ... flash it and see how that feels ... low RPM w/a big cam that has alot of overlap doesn't seem to be as an exact science

Michael Ozorowsky

iTrader: (1)

ok horist. Thank you. I understand the BASICS of the hp tuners software, but the advanced stuff and how to make things do what I want them to I'm a little lost.

Also how do you scale the table by 70% do you select those values then choose multiply .70 or what?

horist

yup, select them, make sure the modify selected is chosen, use multiply and multiply by .70 ... it helped alot w/my cars idle characteristics (it basically makes it run leaner at lower RPMs )

Michael Ozorowsky

iTrader: (1)

ok thank you. Will try that tomorrow too.

MNR-0

Before doing ANYTHING log your O2 behaviour at idle, part throttle and rolling to a stop. Lazy O2s or railing with CAMS will definately cause idle surges and stalling. Get your O2 sensors right before you play with the VE.

It is likely you are overshooting the R/L switchpoint with too much fuel swing. Modifying the VE table will band-aid fix it, but is not the root cause. Get your O2 sensors swinging happily first.

Michael Ozorowsky

iTrader: (1)

mnr can you elaborate please? You REALLY lost me there.

MNR-0

OK. I assume you have HPTuners or something similar to log narrowband or lambda. Look at your O2 mv swings at idle. You should see a sine waveform not a square wave or straight line.

If you have a straight line, then if they are steady at 900mv+ then its called railing and you are running overly rich. If they flatline at <30mv then you have lazy sensors and are either running too lean or god knows what AFR it is. In that case the sensors are usually too cold due to an exhaust or header upgrade and their gain needs to be recalibrated to cause a voltage swing and drive the fuel above stoichiometric 14.7 AFR.

If you see nice looking sine waves at idle and in motion then you are set. Continue on as before. If not, you need to adjust the Airflow mode for the logged g/sec airflow by raising it just enough to cause oscillation.

Just yesterday I detected lazy sensors at idle and railing in motion for closed loop. Having made these kind of adjustments my fuel trims are back inline, getting way better fuel economy and throttle response and better idle. Thats with a stock Z06/Vortech6000 MAF and cal. (aka. VZ MAF here in OZ).

Here are some links and exerpts:

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15 GM V8 Tuning (4.8 LR4, 5.3 LM7, 5.7 L31, 5.7 LS1, 5.7 LS6, 6.0 LQ4, 6.0 LQ9, 8.1 L18) / V8 Miscellaneous Tuning / Re: Trouble Codes 133 153 Nov 30th, 2004, 12:08am
Started by gman75 | Post by rattle
heres what gm says about those codes

DTC P0133 or P0153
Circuit Description
The powertrain control module (PCM) continuously monitors the heated oxygen sensor (Ho2S) activity for 100 seconds. During the monitor period the PCM counts the number of times that the Ho2S responds from rich to lean and from lean to rich, and adds the amount of time that was needed to complete all transitions. With this information, the PCM can determine the average time for all transitions. If the average response time is too slow, a DTC will set.

The PCM determines the lean to rich transition when the Ho2S voltage changes from less than 300 mV to more than 600 mV. The PCM determines the rich to lean transition when the Ho2S voltage changes from more than 600 mV to less than 300 mV. An Ho2S that responds too slowly is most likely defective

So now what you have to do is log some data, are your o2s pegging low, pegging high, or just lazy (too cold), if lazy you could put some catalyst monitor o2s into the engine monitor location (hotter heater elements), or use header wrap to maintain more heat, that is about it for mechanical fixes.

onto the tuner fixes, you get to learn how to adjust your o2 sensor error closed loop proportional gain values to achieve nice active sensor readings again. basically when you look at the table, for a given mv error use the given multiplier to force ocillation. you will notice the bigger the o2 error the bigger the multiplier, so for example if your o2 pegged at 60 mv and the multiplier is 4.00, you may need to increase the lean cell in the table under the 420MV error line. if it was pegged rich you adjust the rich line

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14 GM V8 Tuning (4.8 LR4, 5.3 LM7, 5.7 L31, 5.7 LS1, 5.7 LS6, 6.0 LQ4, 6.0 LQ9, 8.1 L18) / V8 Miscellaneous Tuning / Re: Trouble Codes 133 153 Dec 1st, 2004, 12:29am
Started by gman75 | Post by rattle
if you have exhaust leaks that will definately affect your o2 readings

if you dont have exhaust leaks and you know your sensors are good and you have already tried the rear sensors (with hotter heaters) in the front position and you dont want to put header wrap on to keep the heat in your pipes which will keep your o2s warm enough to operate correctly then you can mess with the 02 error tables.

the tables basically tell the pcm how much to adjust the fuel by for a given amount of o2 error, if the error is small it wont take much adjustment to push afr the other way,

first look at your closed loop proportional gain vs o2 error.

see you have two lines, lean and rich, and mv error columns, 0mv......420mv

the mv values represent how far away from 451mv (or whatever value is set in the o2 rich/lean vs airflow table. the actual values in the table are multipliers used to adjust the fuel ratio to keep the o2s swinging back and forth, now if your o2s are cold due to header they will be reading slow so you will need to increase the multiplier to induce some overshoot that the cold sensor can actually see, dont go too far or you will get a surge condition. Its going to be hit and miss, trial and error and marginally acceptable at best,

just wrap the headers, at least the bottom half that you cant see from under the hood, or better yet get the headers porcelain coated.

Michael Ozorowsky

iTrader: (1)

My headers are already ceramic coated.