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Engine run-on in gear in drive and neutral


Romulus
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Just trying to figure out how to stop the engine from running on during decelerations at low speed with the throttle closed. EG, with the throttle closed the car still 'drives' itself, like the throttle is not completely stuck. I can get DFCO to work above speeds of 85km/h at closed throttle and will keep the injectors shut off to around 45km/h. When the injectors cut back in the vehicle will maintain a constant speed on a level road. When the gear selector is put to neutral the engine rpm sits around 1800rpm until I slow to around 3km/h, then it drops down to idle.

Car is a SZ Territory with a FG turbo engine. I'm running mostly the FG F6 MKII calibration (HAEK4PE) but have also tried HAEK2ME and the XR6 Sprint idle and dashpot settings. Any suggestions?

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Is there an air leak? A good way to check if there is is to log the timing at idle, when you have an air leak it will drop very low eg 5 degrees to try and keep the idle speed at target.

I had the same problems when my PCV line split. Would hang at 1500 rpm until the speed dropped below 8kph, then it would slowly drop to 1k. Car would drive itself in carparks. You could even try pulling the PCV line off and see if it gets worse, if there is no change then you likely already have an air leak.

If you can smoke test the inlet tract.

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If you datalog vehicle speed is the speed correct? Below 5-8mph it uses a different dashpot setting. Set this to 500mph to see if it gets worse or not, this will tell you if you can hack up the dashpot clip table to fix it.

image.png.a5a2c1eeb1b3120191e9615dee93f17f.png

If you have combined various strategies I would get a completely stock strategy with injector data and see if it still occurs. It sounds like the wrong cal is in the car for the engine/intake combination you have. If you have an FG turbo motor, use an FG turbo calibration.

If it truely have changed the engine enough to need to modify the dashpot settings (you almost never have to unless you have rebuilt the motor/have cams/lightweight flywheel etc) then start making large changes to 1 table at a time, eg add 50% to the entire table, note if it gets better or worse. Keep an excel spreadsheet of the changes you made and the results you got to each table on their own. Test at idle, and at 60kph clutching in keeping notes. I would expect it to take a solid hour or two to test all the dashpot tables and keep notes of the results.

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29 minutes ago, Roland@pcmtec said:

If you datalog vehicle speed is the speed correct? Below 5-8mph it uses a different dashpot setting. Set this to 500mph to see if it gets worse or not, this will tell you if you can hack up the dashpot clip table to fix it.

image.png.a5a2c1eeb1b3120191e9615dee93f17f.png

If you have combined various strategies I would get a completely stock strategy with injector data and see if it still occurs. It sounds like the wrong cal is in the car for the engine/intake combination you have. If you have an FG turbo motor, use an FG turbo calibration.

If it truely have changed the engine enough to need to modify the dashpot settings (you almost never have to unless you have rebuilt the motor/have cams/lightweight flywheel etc) then start making large changes to 1 table at a time, eg add 50% to the entire table, note if it gets better or worse. Keep an excel spreadsheet of the changes you made and the results you got to each table on their own. Test at idle, and at 60kph clutching in keeping notes. I would expect it to take a solid hour or two to test all the dashpot tables and keep notes of the results.

The car is a 2013 TS SZ Territory petrol RWD with a built FG engine. Stock cams but the compression ratio is 9.0:1. Will try the various changes you've suggested. Running a turbo calibration in a NA car doesn't work unfortunately, been there, done that. I have to modify the stock calibration with as much of the turbo cal as possible. I'm 99% there, the engine 'farts' during gearshifts, just need to work on the engine run on at low speed with zero throttle.

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Ok sounds like you might have legitimate requirement to change the dashpot settings then with the different compression ratio and the different intake.

I would put aside an afternoon to modify each table and take notes of the behaviour. The tests I would do are something like this. Only change one table at a time and make large 20-50% changes so the change is very obvious. Then from this data you should be able to figure out which tables to change to get the desired behaviour.

image.png.c81ada4d2a50a128e5ab4f47fb59b348.png

You'll never get it right willy nilly changing things (or as I call it, shotgun debugging). Test it scientifically, and you'll only need to do it once.

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  • 4 weeks later...

To recap, I've essentially had to reduce the airflow in drive at 1000rpm to 0.5, 1150rpm to 0.25 and 1300rpm to 0.15 to get the engine to decelerate. Given the different compression ratio of the pistons over the stock comp there's a bit of tweeking of the tune to be carried out.

I've been able to get the fuel cut during gearshift to work so the engine now 'farts' between gearshifts. So far, the stock NA trans behind the heavy Territory is holding up well with 20psi boost from a Gen 1 GTX3582R, the engine must be making around 400-420rwkw with the current accessories.

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  • 2 weeks later...

Problem fixed. Ive reverted back to the stock HAEM1AF calibration and from there applied changes necessary for the engine and transmission. Copying the engine and transmission development parameters caused issues with the calibration.

The Territory is now behaving like a stock Territory, albeit with a turbo engine. The gearshift burble from the FG turbo is functioning as well. I've found the parameter which enables this feature.

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auF0261 - Other torque cut limits

Transmission Shift Modulation  is where you can adjust how much or little burble you get ( 0 no burble -> 1 more burble)

Using only Spark cut(auf0262) on this requestor will remove all burble/fart and have large -ve spark adv on shifts.  Will also cause overboost on gears shifts.

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8 minutes ago, finnigan001 said:

auF0261 - Other torque cut limits

Transmission Shift Modulation  is where you can adjust how much or little burble you get ( 0 no burble -> 1 more burble)

Using only Spark cut(auf0262) on this requestor will remove all burble/fart and have large -ve spark adv on shifts.  Will also cause overboost on gears shifts.

While this works for the Turbo models, the shift burble isn't activated in the NA calibration (Territory).

auF12216, auF10971, auF1338, auF10020, auF11419, auF11779, auF10533, auF11392, auF11857, auF11992

These are the parameters changed from stock to enable torque truncation and fuel cut during gearshift for my NA Territory calibration. I believe you cant just apply a turbo calibration to a NA calibration as the PCM hardware is different. The NA PCM does not have an allowance for the wastegate solenoid. I'm running an Eboost Street to control boost. I cant utilise the boost by gear and WG tables, that's a limitation using the NA PCM.

 

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  • 1 month later...
  • 9 months later...
On 3/3/2020 at 8:05 AM, Romulus said:

Problem fixed. Ive reverted back to the stock HAEM1AF calibration and from there applied changes necessary for the engine and transmission. Copying the engine and transmission development parameters caused issues with the calibration.

The Territory is now behaving like a stock Territory, albeit with a turbo engine. The gearshift burble from the FG turbo is functioning as well. I've found the parameter which enables this feature.

is that AUF2565 TQ reduction, on my terry that's set to 3 but looks like its set to 4 on fg's? is 4 a straight to fuel cut? 

Edited by BeerTurbo
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