os63

Good day.

I am a bit puzzled here, and in the hopes some smarter one (than me) might be able to help me out.

I've got a 383/superram with victor JR heads and hooker 2151-1 headers. I don't run cats, air, egr or charcoal canister. All this is disabled on my $6E, as well as 36 lbs/hr injectors approprietaly set on injector flow rates.

I have it set up to idle at 875 rpm.

Whenever I put it from N or P to D, or R, it stalls.

It will stall, also, if I give the pedal a tap and lift off quickly.

I would go to a commercial tuner, but unfortunately there is none here in Nordic Europe

I have a scan with the P->D happening, taken with TunerPro RT;

http://sneits.fi/stall.xdl

...and also exported as Comma-Separated-Values,

http://sneits.fi/stall.csv

If one of the kind souls would be able to help, I'd really appreciate it.

The "Target AFR" is not on calibration, but rather output on DIY-EFIs wideband project.

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The car is able to keep on D, if I coach it a bit on the gas pedal.

I've tried raising stall saver RPMs, I've tried raising learn value on IAC up to 80, and lowering it to 10. None of this made any difference.

Thank you in advance, and happy Easter.

tequilaboy

I took a look at your datalog earlier. I have to think you may have a locked torque converter or something mechanically wrong with the transmission for the revs to drop so suddenly when shifting out of P or N.

A couple of general observations:

Spark advance is relatively high, approx. 40 degrees at your idle rpm and load. 28-30 degrees advance is more typical for a modified engine. 20-24 degree is typical for a stock L98.

Engine has a significant appetite for air, approx. 13 gm/sec at idle, and a relatively high idle load > 70.

Either the excessive spark advance is killing the torque, or the engine has high frictional losses to require so much air to idle at 875 rpm.

Tps voltage is on the low side at approx. 0.45 volts. This means extra throttle opening will be required before the IAC begins adding counts to follow the throttle. This may explain the stalling after a throttle blip.

Try reducing the spark advance for the idle load and rpm region by 10-12 degrees or more.

Reset the tps for approx. 0.54 volts with closed throttle.

These things should help, but I suspect there is something wrong with the transmission.

os63

Thank you for speedy help, I will try out throttle valve and TPS and retard the ignition cells at that area. I will also check out if TCC is fed with voltage. Dropping the tranny and seeing how much effort rotating the converter will be a little bit more, so I'll try that as the last item.

LV8 at 70 surely looks like a lot, as the scale is only up to 255; this is over 1/4 of the whole LV8 scale.

os63

Mr. Tequilaboy,

Thanks for the help.

Putting the ignition timing on LV8 and RPM range we use to less-than-30, and the car now doesn't stall coming out of P/N! It does, still, twitch to around 500 RPM for a short hesitation, but "regains" quickly back to where it is supposed to be. I believe taking it further back another 3...5 degrees will improve it even further.

We're also at around 0,54 volts on TPS for closed throttle.

However, LV8 goes 90'ish on D and R; I will test this by disconnecting the torque converter and tranny, and find out if that changes LV8 significantly.It seems I was not too smart, I assumedthat I was on the spark advance associated with smaller LV8s.

Unfortunately, I managed to do a stupid, stupid thing. I verified IAC resetting with the IAC off the TB. *sproing*

A new one is on order and will only appear on Wednesday. I was, however, doing quite nicely before I f'd up the IAC.

Again, thank you for the observations, it did make the difference on the stalling issue I wish there will be a way I can return the favor in future.