stock and idle issues

[gcc522]

It ran fine without the QH and with the QH using the stock A9L bin/ADX/XDF. All the issues started when I installed the latest A9L2/ADX/XDF.

Would the EEC self-test be able to find the source of the problems?

[decipha]

thats simple enough, if it runs fine on the stock tune just run that

you cant open the throttle stop with the key on. Key has to be off otherwise will set part throttle.

[gcc522]

Thanks Michael,

I'm concerned that my stock engine would have so much problems with your more sophisticated tuning that I was hoping to take advantage of.

[decipha]

simple check is to see if anything on the dash turns red

[gcc522]

I made a couple more attempts to reset the idle speed,but got the same results. After the engine warmed up, it would start idling around 800 rpm, and the only numbers showing up in yellow were FUEL_APT_LAST flickering to -1 occasionally and WB_1ER_AEMEUGK hanging around .64. As I drove around, the idle steadily crept up to about 1200 rpm. I didn't drive around long enough to see if it kept increasing. But each time after I shut the engine off and restart, it would start idling at 800 again, and again wold creep up as I drove more.

Tonight I set NEWBASE to 700 and uploaded the otherwise A9L2_240103.bin into the QH and ran the engine to let it warm up. It idled between 700-750, and seemed to behave itself, the idle never exceeding 800 as I did the same around-town driving test.

I'm going to update this bin to work with my newly built 331 stroker. It will have bigger injectors and MAF sensor, so I will at least have to update those tables. I'll also be installing a more aggressive cam. I'm sure there are other adjustments that have to be made.

Where is the best place to start?

[decipha]

APT flickering to -1 is a major problem and explains why your having idling issues

need to fix the tps first before you can do anything

[gcc522]

Reset TPS and idle according to directions, ran some more test drives and find:

The stock A9L programming also seems to creep up the idle as I drive, topping out around 1000 rpm. But when I come to a stop, the idle slowly drops back down to about 700, the stock setting. The A9L2 does not seem to look at VSS, so when the programming brings the idle up to 1000, it just stays there, and may creep higher the longer I drive.

The issue with the stumbling has been narrowed down to cruising on the highway in 5th gear at around 1500 rpm. One characteristic I notice with the A9L2 code is that as soon as I let off the gas pedal (close the throttle), the air is cut off immediately, so if I was a little late in releasing the clutch, I create a shudder due to the engine speed dropping suddenly. When I do the same on the stock A9L, it cuts the air slowly, like an anti-stall dashpot. I think this is to reduce the enrichment that would be caused by fuel wetting the runner walls evaporating due to a sudden drop in MAP.

I think the abrupt cut-off of air by the A9L2 code may be the cause of the shuddering I'm experiencing, as it over-reacts to the condition. I can either stop driving at such low speeds in 5th gear, or try to dial in a little more dashpot delay.

[decipha]

reset tps? Ivs never heard of that before, what does that mean/ how do you do that?

a9l nor a9l2 never brings idle up to 1000

it sounds like you have something screwy going on

you would kick up the dashpot airmass at that rpm to soften the ct transition

[gcc522]

resetting the base idle speed per:

http://efidynotuning.com/idleair.htm

where you baseline the tps.

So what might cause the EEC to crank up the idle speed as the engine warms up? A failing ECT?

Clearly, the stock A9L is doing something to bring the idle back down as the vehicle speed goes to 0.

[decipha]

if you did a base idle reset and still having issues something is differently wrong

nothing turns red on your dash?