Strange engine judder between 2000-1700 RPM

Give input on tuning as well as any tips and tricks you may have. Also feel free to share base mapping files for various engine types.
Dayle
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Strange engine judder between 2000-1700 RPM

Post by Dayle »

Hi all, I currently have a Vauxhall Nova C16XE running a DTA S40. It has been mapped at the rolling road but suffers a strange behavior on the road which it doesn't do on the rolling road.

Basically car drives fine but when slowing down and using the engine to brake off the throttle or very light throttle when the revs hit 2000-1700 the car violently shakes, you dump the clutch and the revs fall and the shake goes, same if you accelerate it goes.

I've been to the rolling road twice now and the tuner said it will be due to the ECU trying to going into a idle state quicker than the engine is actually slowing down.

Engine uses a single throttle body and ignition timing to control the idle, also TPS as load.

The first time we went to the rolling road for the run in map the car did the judder but quite mild at around 2000-1900 RPM the second time he altered the Idle and its now quite a bit more aggressive and over more of the rev range (1900-1700) particually stop start in traffic.

Anyone any idea's on what to change or where to start.
stevieturbo
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Re: Strange engine judder between 2000-1700 RPM

Post by stevieturbo »

First thing....turn idle control off. That will at least rule that problem in or out.

But doubtful the problem is anything to do with idle control. As the mapper programs it, so if he is blaming it, why didnt he change it ?
Dayle
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Re: Strange engine judder between 2000-1700 RPM

Post by Dayle »

Map 1 = running in map
Map 2 = latest map (Tuesday)

He did change some of the settings in there on Tuesday from the running in map and it seem's to have made it worse as its now lower in the rev range where you sit in traffic.

I have come up with a temporary sort of fix by copying the latest fueling and ignition timing cells from map 2 into the running in map 1 file and the judder is now bearable as its a 2k revs rather than 1700 but its still annoying.
Dayle
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Re: Strange engine judder between 2000-1700 RPM

Post by Dayle »

I have attached a image of the two different idle settings. these other than the fuel and ignition maps seem to be the only difference's that i can find in any of the options.

Image
JON-TEC-RALLYE
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Re: Strange engine judder between 2000-1700 RPM

Post by JON-TEC-RALLYE »

hello, the problem is in excessive use (ignition timing). 40 degrees seems too, without seeing the 14x20 table is difficult to know. HECO many corsa B hays and never had problems like that. esosi configuration is very different from yours. if you want to send me an e-mail and correct it. greetings.

jonaycastro@hotmail.com
DTA--MoTec--Link--Ecumaster--HONDATA
stevieturbo
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Re: Strange engine judder between 2000-1700 RPM

Post by stevieturbo »

it has absolutely nothing to do with idle control. If that's what your "mapper" told you, go elsewhere.
Dayle
Posts: 32
Joined: Fri Sep 23, 2011 1:33 pm
ECU Model: S40 Pro
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Location: Wigan
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Re: Strange engine judder between 2000-1700 RPM

Post by Dayle »

Jon If I can send the maps could someone have a look?
JON-TEC-RALLYE
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Joined: Sat Jul 30, 2011 4:35 pm
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Re: Strange engine judder between 2000-1700 RPM

Post by JON-TEC-RALLYE »

send your mapping, above is my mail.
DTA--MoTec--Link--Ecumaster--HONDATA
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86sixsix
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Re: Strange engine judder between 2000-1700 RPM

Post by 86sixsix »

what JON-TEC-RALLYE said. s40 + loads of ignition on overrun just less then 2k = learner driver bunnyhops but 'backwards'.

only in those cells too....i'm sure it spanners the dwell without telling anyone.
Renault 1.6 K7M, '92 Clio 16v shell, Rotrex C30-74, S40, Faceache, Sh***er, YouTube Blue Shed Channel
Dayle
Posts: 32
Joined: Fri Sep 23, 2011 1:33 pm
ECU Model: S40 Pro
Firmware Version: 58
Location: Wigan
Contact:

Re: Strange engine judder between 2000-1700 RPM

Post by Dayle »

Cheers for this, Still does it but its cope able now. Jon must be a little warmer in your country we had frost here last night and the bugger wouldn't fire, Had to get the laptop connected and change the start fueling, all runs now but i think i will need to have a play with this.

Anyone got any good pointers for this air temp was -1 this morning.
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