First off, I thought you meant neutral safety/starter enable when you said P/N switch. As far as any of those, they are simply disconnected from the ECM.. My mistake. The neutral safety switch is wired closed so I can start the vehicle without stepping on the clutch. I believe the P/N is a pin that gets grounded when not in drive, correct?

Am I wrong ?

Keep in mind, its a v8 supercharged car. No turbo. The o2 sensor is in the collector of a shorty hedman header. Its a 3-wire (brand new) delco sensor.

I'm gonna go give it a try with the recommended bin changes. I'll post my results in a few hours.

Thanks for all the help, all of you. You give me hope!

-- Joe

 

Joe, concerning the P/N switch you have it correct.

RBob.

 

Ok. Mixed results.

I drove down to my shop..

I stopped in the lot, then tried it. it bucked a little, them smooothed right out, then bucked a little more, then smoothed right out. I had a grin on my face. I was like "almost fixed!"

So I saved the .csv as almost-fixed.

I switched to my old bin, and verrified it bucked like nuts. (old-bin-bucks.csv)

Then I switched back, and tried it again, expecting the same results as "almost fixed" but I ended up with "maybe-not". It bucked like crazy.

.csv's and .uni's are all in:

http://members.cisdi.com/~anesthes/bucking/july1/

I dont get it.....

-- Joe

 

Hi dude.

I understand your feeling on this intemittant problem.

No matter what code you run, there is a fault.

I had very similar issues recently. I would get a fault lamp, heavy fueling, and popping on decel. Swapping computers, and chips didn't fix it.

The problem?

The socket I fitted on the memcal so I could change roms, had a pin or two not sitting right. I originally just carefully desoldered the stock rom, and whacked in a machined pin socket- literally.
Worked like a charm for ages.

I readjusted the contacts with a pick, and will really have to solder them one day.

I used the same memcal in the alternate computer- so the problem carried over.

Just have a look.


Sean

 

I looked at the lastest log files. If I correctly understand where the bucking is taking place you now need to work on the VE tables. Leave the other changes in place as one item builds on the next.

Notice that between 900 and 1000 RPM around 45-50 KPA the O2 goes lean and the INT starts to climb. It actually goes to 150.

This lean AFR will casue a surge in speed, typically followed by a sudden drop.

At RPMs lower then 800 the AFR is rich. The INT will drop as low as 107. The power will come back allowing the RPM to again increase. As it does it hits the lean area again and surges/loses power.

As for the VE tables there are two 3d tables. One is used is the RPM is less then 1600 RPM AND the throttle is closed. If the throttle is open OR the RPM is greater then 1600 the other table is used.

Each table is also summed with the 2d adder table.

As most of the surge across the lot is with a closed throttle and under 1600 RPM the low speed table is used. To tune this table can adjust it using the O2 data and/or INT data (short term trim). Look at the RPM & MAP over a steady area and adjsut accordingly.

I am sure with some tuning of the VE tables the surge will be eliminated. Also check the continuity of values between the two 3d VE tables. Else a sudden change in PW will occur when the throttle is touched open.

RBob.

 

HI!

My next step was to fix the VE. It appears those changes have caused the closed throttle VE to be entirely different. I was watching BLMS while going down a street. On tps, blms were like 125ish. on 0 tps they shot to like 138.

I gotta run out of state today, but tomorrow I'll adjust the VE tables see if I can get a consistant blm/int accross the board.

Thanks again for all the help!

And to the other guy, I had that problem in the past with bad sockets - but that will allways result in a check engine light.

-- Joe

 

Well.. I got some gas today at an econ station (not where I normally go) and apparently not all 93 octanes are equal. BLMS are wicked wicked high, at the same pw as the day befores logs. temp and humidity is pretty much the same..

Guess I'll burn off this tank of gas, then try agian.

-- Joe