john banks

I thought I might try and hunt for the cause of this - you know the hesitation at about 2-2500 RPM on light throttle when cold. If we can get a few logs of different cars it might help. It could well be a bug in the ECU software, but if it is something in the map I'll see if I can hunt it down.

Also if you can identify what revs if occurs at that would be nice.

Feel free to email them to johnbanks@dsl.pipex.com - don't worry I have broadband

babber

John,

You don't have broadband, you have ADSL

I'm thinking about getting deltadash, what do you need a few logs on a AE802 ECU when cold ?? And the RPM noted ?

Cheers Phill C

john banks

OK Phil it is medium band If your venerable company supplied here I would not have hesitated!

Yes particularly at that hesitation area.

babber

LOL, on my car it was around the 2100 RPM mark.

Sorry about my company letting you down, have you considered moving

Cheers Phill C

LOL unless you were around 2100 RPM on a MY00 (AE802 Green) ECU

[Edited by babber - 5/21/2002 7:50:23 PM]

SCOSaltire

if u like john, i can come down sometime and u can log my prodrive chip...

babber

John,

That's reminds me sideways reckons his has started doing it now V reg RB5.

Cheers Phill C

john banks

They all do it when cold at low revs. Difficult for you to visit SCOSaltire as it needs a few hours to cool down to do it. Thanks anyway.

Cosie Convert

I don't think this happens on early WRX's, certainly not mine

I can hazard a guess that it is the fuel map on open loop at light throttle, (before the O2 sensor has heated up enough for closed loop to takeover) This section of the MAP is not used at any other time other than cold, light throttle running.

Problem will be monitoring O2 as the sensor is non functional when cold
It is probably a shade weak at some point as engines will run fine even exceptionally rich when cold.

One of the few occassions I would recommend more fuel

Andy

john banks

I meant all the Phase II engines.

You can see it on the airflow trace - looks like a bumpy road even though the throttle position is steady. The fuel injector pulse widths move in complement to the lambda voltage because of the air fuel correction. The timing does look a bit bumpy on a cold run and then smooth on a hot run, but this could be because the fuelling is bumpy. Chicken or egg. It is really quite mild when you are looking for it - just a hunting. Would be nice if it could be removed though.

Could not resist a few drag runs whilst out. Spinning all four wheels in 2nd on a slightly uneven bit of uphill in the dry. As standard the car did not do that in the wet. What have I done

Floyd

iTrader: (9)

I can see a new post vey soon....

New gearbox needed, who can assist?

F

john banks

OMG, 7.17s from 63.4 to 105 mph (approximation to 60-100 as best I could determine from gearing). That could be a 12 on 0-100 if I could actually launch the thing (I'm not trying cos of the gearbox ). It is nothing like a Cosie Convert time but I am pleased

30-70 from speedo logs 4.32s, 34-74 4.54s, 32-74 4.68s.

I reckon about 4.6-4.7s for the genuine article, considering the gearing I am again quite pleased.

[Edited by john banks - 5/21/2002 11:03:24 PM]

john banks

The first one right at the end of the log there is a hesitation - you can see the airflow is bumpy - the timing looks quite bumpy too despite the smooth throttle signal. The second one the horizontal scale is different, but it looks smoother. The timing is smoother.

Looks like it is not a consistent area of the map and the hesitation is quite subtle.

[Edited by john banks - 5/21/2002 11:22:03 PM]

Cosie Convert

Excellent times John I recon Sam's lurking 'quivering' somewhere

Can't see where the hesitation is on trace 1 ? the engine speed seem to increase fairly contantly.

WREXY

Out of topic, but just noticed different software on the delta log graphs, with selection boxes on the top of the page of the logs and size of graph selection too. Is there a new version to download or have you modded something John.

Cheers,

Wrexy.

[Edited by WREXY - 5/21/2002 11:59:47 PM]

john banks

I am testing a few beta versions. You never see the RPM "quivering" when it does it oddly.

[Edited by john banks - 5/22/2002 8:35:23 AM]

The_Max STi

John

I would love to know the answer to this hesitation problem.. My 98 Sti 4 does it all the time between 2000 and 2800. The car does not have to be cold to do it..

Seams only to happen in traffic or when trying to keep the same speed say 25-30 and is some times quite violent but goes straight away when you put your foot down a bit more.. There is no such problem when over 3000 though..

I would offer my car for a test for you but I think Scotland is a bit far for me to travel.!!!

Rob.

john banks

Sadly only V5 and after can be logged with Delta Dash. There seem to be no jumps in the timing map around the zone it happens, and 4 extra degrees of advance in that whole area made no difference to this phenomena.

SCOSaltire

as a random thought....

perhaps the oil is not up to correct temp and valves are making ticking noises that the knock sensor is picking up thinking its knock?

told u it was a random thought...

john banks

Maybe but there is no knock retard at all - I did not show the graph but checked.

Cosie Convert

Lamda sensor reading artificially high when it's (the sensor) is still not fully up to temp ? They read low when they get too hot so maybe ????

Oooops gona miss that flight