julesf

Guy's I'm a bit confused about this.

This is a statement taken directly from the Simtek tech details web page:

"Closed Loop Fuel Control
The ECU uses the OEM narrowband lambda sensor to give optimal fuel control in the idle / light throttle / cruise regions. The ECU checks that the signals from the sensor are valid, and will switch to Open-Loop if it believes the sensor to have failed. As an option, it is possible to connect a true wideband sensor."

I also feel that this statement from the FAQ page of the Simtek web site is
also relevent.

"Q:Will my car still pass the MOT?
A:The SimTek still uses the stock lambda sensor to control idle and part throttle fuelling, so assuming no other modifications are preventing the correct emissions from being achieved, the car will still be able to pass.

So on purchasing the ECU I am assuming that closed loop fuel control is already active ?

Anyone care to comment?

*Please note statements copied from http://www.simtekecu.co.uk/

Jolly Green Monster

iTrader: (4)

Yes that is correct

Closed loop fueling works very well using oe lambda sensor etc

Simon

julesf

Thanks Simon,

So why is everyone on this thread waiting so desperately for a Closed Loop Idle update. Surly with Closed loop O2 sensor controlled fuelling, the car should idle sweet at the correct AFR as it does with the stock ECU

Just interested really.

Thanks,

Jules.

www.Type-RA-Sprinting.com

howes124

iTrader: (11)

i have a simtec fitted to my 1993 wrx, spot on as idle was a bit off to start with but on 2nd map from duncan doesnt miss a beat hot or cold.

Jolly Green Monster

iTrader: (4)

closed loop idle control is different to closed loop fuelling on idle.

9 times out of 10 they do idle smooth without issue, sometimes it takes more than one visit / mapping to get it 100%..

closed loop idle control - target an idle speed of say 900rpm and the ecu will increase and decrease the idle speed to ensure it remains at 900rpm.

closed loop fuelling - the ecu monitors the lambda sesnor is and removes or adds fuel to keep the fuelling at required setting.

Simon

swisstonihasher

Is there any update on beta testing?

happydude303

iTrader: (1)

what i would like to see from simtec is some sort of knock control where is the ecu see det or knock or any thing other then the norm then it will retard the settings to keep your engine safe just liek the old scholl aultronics ecu does as my idle is fine really never really had any issue with it but i must say it does take a while to settle down on a reall cold start

Grant74

iTrader: (10)

JGM sorted my idle and an extra 10bhp, and basically all well since then, but have heard no updates on the ecu?

petedotuk

I turned the closed loop 02 off, it was always hunting trying to find lambda and if I watched my LM 1 it would always fly past it to extremes, ie never getting close.

With it turned off I adjusted the air by pass, ignition & fuel and my car idles perfectly @ 850rpm bang on lambda utill I get heat soak and the multipiers kick in and it idles around 950rpm and 14.3>1

Are the updates ready yet? I want the knock control and wideband reading for datalogging done at the same time.

Jolly Green Monster

iTrader: (4)

Pete yhpm

petedotuk

Thanks Simon.
YHPM also

andy97

iTrader: (1)

I think the Simtec company has failed to deliver on required features like active knock control for the earlier models. This has been mentioned for over a year now and still no sign of it appearing

Come on Simtec get your a~se in gear, and deliver what you promised!

Andy

Considering a different ECU

happydude303

iTrader: (1)

yeah i second that get your **** into gear starting to wish i had got my self an aultronics ecu and there old school now and they have it and two maps and all the anit lag and launch control

banny sti

iTrader: (68)

Get yourself a Syvecs, I switched to a simtek on the day of mapping and glad I did

tsl202

sorry hijacking this post but with my Hydra ecu i still have the same idle issue, as JGM spotted when remapping my car a few months ago. since i changed the lambda sensor who was faulty. but the hunting continue, from +-500rpm to 1300rpm and sometimes it turns off in the traffic! i've been told to change the idle control valve because it can be the weak link (faulty/damaged). my mileage is very poor about 15-18lts/100kms (don't know in mpg). as the guys at tracktive don't answer me i'm asking any tuners here if they can help me to solve this problem.
thanks
Daniel

julesf

Yes Simon sussed that It's just that earlier on in this thread some members were saying that the idle was inconsistent from summer to winter
I just wondered why this would be. Surly with closed loop fueling at idle and temp sensor input the ECU should be able to trim the parameters to maintain a consistent idle quality. Hunting when warmed up seems to be another common problem.

Jolly Green Monster

iTrader: (4)

because it does't have closed loop idle.. (yet)

there is more to it than just fuelling and air temp.

Simon

wrxsti280

iTrader: (6)

I have the same problem with idle, and mapped by duncan who has been to the car twice and still can't get it to idle properly, I'm not blaming duncan here by the way, but this fix has been mooted for well over a year now, and its obvious that there are lots of people out there that are pissed off with the whole situation, me included!!!!

Simtek have basically in my eyes released and sold something that doesn't work properly and are now chasing their ***** trying to put it right with no luck so far.

COME ON SIMTEK, DO THE RIGHT THING AND GET IT SORTED AND ASAP!!!!

Jolly Green Monster

iTrader: (4)

it should be possible to get it satifactory within two visits.

I think if it were a simple alteration it would have been done already.

Simon

dynamix

iTrader: (3)

The issue is the idle control valve sticking IMO on yours Steve.

Jolly Green Monster

iTrader: (4)

what year? 99/00? they often require a good clean.

Simon

MartynJ

I think you are being more than a little unfair with your outburst there.
The SimTek ecu works perfectly, the fact that some (Most of the time through no fault of their own) can't get them to idle perfectly has nothing to do with the ecu itself.
My wifes daily driver has a SimTek installed and idles perfectly, winter, summer and anything in between. Most of the time the problem is that the mapper doesn't get anything like enough time with the car, because of this we can't test it in every situation. The closed loop idle update is coming and will help those that don't actually have a fault, it won't however help those with faulty or sticking control valves.

Martyn

wrxsti280

iTrader: (6)

Duncan, I thought we had ruled out a sticky idle control valve? Your last words were that you didn't feel it would get any better until the software update was released but that had been on the cards for over a year and was anyones guess as to when it would be released
the fact is that after spending a not inconsiderable amount of money on something, my car idles like a chug boat and forgive my abruptness but I'm not happy with the situation

f4la k

iTrader: (1)

Never really had any problems with mine, but i suppose thats because it was mapped by Andy F.

wrxsti280

iTrader: (6)

Its a my94 sti wagon and we checked the idle contro valve and that was fine

Jolly Green Monster

iTrader: (4)

Agree with Martyn, assuming nothing wrong with your car wrxsti280 then shouldnt be like that, is it on cheap injectors?

greekpeterfromlondon

iTrader: (2)

My UK 94 was mapped by JGM and the cold start and idle was spot on but over a few weeks it developed a very lumpy idle and a miss on idle.
But since blowing the turbo i have replaced the turbo and the early coils for the new age coils
and i must say the car starts and idles like when i had my Apexi PFC.
looking forward to letting Simon give the car a map tweak to see the defiance in the car.

wrxsti280

iTrader: (6)

Norma subaru 380,s

Jolly Green Monster

iTrader: (4)

So either the map or something faulty which should be obvious like coilpacks in peters case above

wrxsti280

iTrader: (6)

plugs and coilpacks were changed as when car was first mapped it did misfire at high boost, all correctly gapped etc etc, the idle control valve was checked as well as it was initially thought to be causing the problem, however, when i took it off it was spotless, i assume that there is nothing else to check on the idle control valve???

Martinj - i take onboard your comments and perhaps i was slightly harsh with my response, but im sure you can understand my frustration, i have gone from a car that idled absoloutley on the money, as smooth as a baby's bum, to a car that idles badly whether hot or cold, although mainly when warm. it is touted to have factory idle characteristics and quite obvious from the amount of people who are having problems the same as me, it isnt factory quality!!!

at the end of the day, all i want is my car to run perfectly, i am seriosuly considering getting rid of the simtec now and looking at other options because of the problems im experiencing, and the fact that simtec dont really seem to care how long the relevant software upgrades take!!!!