i have simtek ecu fitted so i no longer have a maf.
when started from cold the idle is spot on, but when the engine is at norm temp the idle jumps between 800-1000rpm.
the revs go up and down every 3-4 secs,it did do this when the oem ecu was still fitted but it happend every 10-15 secs.

this lumpy idle gos when the o2 sensor is turned off with a laptop pluged in to the simtek.

so do you think its a duff o2 sensor or could it be that the engine is running richer since the simtek was fitted and the o2 sensor is doing its job.
i have had abit of work done as im running 330 on my uk classic

 

I have heard of quite a few issues of poor idling with the Simtek - suggest you talk to your mapper as I think this may be a known problem...hopefully with a known fix

 

I'm presuming it is an Engine Tuner mapped car from where you are based.

Chat to your mapper - they should be able to solve.

 

I have the same issue with my simtek...my mapper (Bob R) did loads to improve it on last map by using his own wideband sensor (fitted in place of my narrow band sensor in mid section) - used to idle up and down all the time but now almost perfect sometimes and then others (when between hot and cold or cold, might vary like yours 200 revs which is very annoying at times in traffic. My cams have been blaimed for part of this issue, they're 285 pipers, what are you running?

Did you find a complete fix?

I'm hoping Simtek do firmware release asap which will allow wideband rear sensor fitting and map, should improve things further.

 

Its a map issue or rather can be resolved... speak to mapper..

SimTek are very soon doing a new release of firmware with closed loop idle control among other upgrades..
at the moment the idle is controlled in basic terms with duty on the idle valve / stepper motor, fuel and ignition.. it will have a target idle and should be a lot more stable then.

Simon

 

all sorted now,had a software update.

 

Hey Simon,

Thanks for the update - I thought simtek already had closed loop control but hey...I know Bob's talking of update for ECU but for knock control, I'll send him a mail. Def mapping/software though, my cams wont be part of this issue, 285's? Excellent.


Stewart, when did you have your software update and was it just a plug into laptop and go or did you need send ECU off? If that's all you need using a narrow band rear sensor and smooth idle, great! No point doing upgrade for wideband as idle is my only issue now.

Thanks Guys

 

Just to correct myself (as I didn't fully understand the process at last map) Bob used wide band sensor to sort rich running, not idle - which he's done velly well, idle is only issue left.

Bob's comments were:
There are no guarantees that the closed loop upgrade will sort your variances out but having that feature is far better than open loop so will help.

I used my wide band to check your “rich running” concerns not to sort your idle by the way.


Plus updates will be as follows:
Knock control
Closed loop idle
Wide band control via the LC1 Innovate unit. The link to that is here LC-1 Lambda Cable with 02 Sensor : Wideband Controller Cable for Dyno, ECU, Data Acquisition, or Gauge Applications

Not sure I'll worry about the wideband side of things if closed loop does the trick.

 

mine does the same do we know when these updates are available ???

Tim

 

before Christmas is the plan

 

Are all the upgrades FOC and are they easy for the mapper to sort?

 

I have the same idling issues with mine, which is a shame as it's the only niggle I have and in every other aspect I find the simtek an eccellent ecu and far superior to my previous Gems...

I spoke to Steve Simpson recently about the knock control upgrade, and was told it would be ready shortly as an FOC software upgrade to anyone who already has knock detection. He said I'd just need to send the board back to Andrew Leech and that everyone would be told when the software was available, but didn't say how exactly this would be done...

It would be nice if the closed loop idle control was ready at the same time and also FOC.

 

speak to mapper regarding the idle as it is relatively easy to sort.

I believe the intention is for all the upgrades on the board to be FOC.. there is then just the set up time on each car by mapper to sort..

Simon

 

if the upgrade is free,i recon you will be charged for his time,bern does yours hunt on idle,mine does it that bad sometimes it stalls out and have to hold the throttle on.done it from day one.

 

Mine idles perfect only changes a little if the fans come on

 

shouldn't idle that bad.. speak to who mapped it, if they don't know they can't fix it

 

It's nowhere near as bad as it was Dave!He altered it before that rolling road day,and said he would do it properly when he maps it again!!

 

Would still like to know what this software update is? Bob said he'd be speaking with Simtek about it to see what this software update is.
I'll need the release to be knock and closed loop idle at the same time, cant keep doing these tuning visits to get something fixed any more.

My idle is okay sometimes, still vary slightly, and other times it wants to stall or up/down but 200 revs plus...shame as you say, great ecu, needs more.
The updates are FOC (so I've read) but run with tuner wont be...

 

idle and knock and an alteration to air temp sensor compensation ignition correction table all in one go

 

When Simon did mine, we had an issue with idle when it was hot. Turned out to be interference from the HT leads to the cam position wires.

A bit of tin foil, and slight resposition, later helped. Simplest way to tell is to move the HT leads on the left of the engine (as you look at it with the bonnet up) away from the bundle of wires.

There is also a tuning answer, but real problem was interference.

Hasnt hunted since.

 

My idle is also lumpy.
It is a common issue...but can be fixed.
Which I will get sorted at the next map

 

may sound daft but do any of you guys find the idle issue worse in damp raining weather,as mine is,constant hunting when its raining and never goes away until the weather picks up and then its only ever so slight,unless i do a hot start of the engine,where it will keep hunting between 400-1100 rpm and trying to stall for about 30 seconds.

 

The software update due out before Xmas is for knock control,closed loop idle and revisions to the air temp retard strategy.

Closed loop idle feature will not in itself solve the above issues; the most common cause of hunting at idle is that the closed loop lambda parameters require tweaking to prevent the lambda correction "overshooting" and causing a momentary weak mixture.

Hot start stalling is normally due to the fuel becoming hot in the fuel rails and causing a short period of lean running and can usually be cured by additional time decayed fuel on the fuel correction maps.If the condition seems to vary with weather then maybe the fuel correction air temp parameters require a tweak also.

Steve

 

are these available through our mappers ?

Tim

 

That all sounds like mapping, thanks Steve - with closed loop control being an extra sweet in the pot. Any of these lucky people that have decent idle with simtek have wild cams? 285 duration on mine...

Grant, is yours classic? Just wonder with the tin foil trick if its good for new age with coil packs.

Lol, we still dont know what Stu's software update was...who did his simtek?

 

Mapped a Newage car equipped with 278/274 Cosworth cams just this morning, idles like stock even with 1100cc injectors, hot, cold and anything in between.
FYI we mapped Stus car and the idle issue was as Steve mentioned, the CLL overshooting causing a brief weak spot. Revised CLL settings fixed the problem and we may have the firmware upgrade installed for Stu later for the CLKC and CLIC.

 

Mine is a classic, but uses coil packs I believe- issue was the leads to the plugs, rather than the coil packs.

For the record, I have now gone posh, and replaced the tin foil with Alu foil tape

 

Wow, stock idle with 1100cc injectors, mint! Mine are "only" 800's and cams about the same....I'll check with Bob then for final tune up as idle should be same as others then.

Grant, how posh though? Did you buy a whole tape or get someone else to buy it for you, then you use just a snip of it, proper posh

 

Steve, this car is not using closed loop lambda at idle its simply not a responsive enough system at that point for that, needs to be a lot faster and could also do with more range setting parameters. Above 1200 rpm its brilliant. Tony is particularly fussy about the fueling under off boost running and idle, he reported that his only "issue" was that under some conditions in traffic when moving the idle sometimes dipped a 100 to 200 rpm then recovered, now that would relate to fan tripping in and out. So are we also going to get engine load idle compensation as well, as per the aircon offset?
Air Temperature compensation will not help fuel atomisation due to heat, only fuel temp compensation will do that, it could be 24 degrees in the intake and 98 degrees in the fuel rails when starting. You need to run a car richer than normal to compensate, but it will be richer than ideal under all circumstances except those involving hot fuel to the point of poor atomisation.

Love Martyns post ... enjoyed every word.

Thanks for clarifying the non-availability of a patch for the closed loop btw, Simon had everyone going there for a second.

Normally I would set the idle to fuel in the low 0.9's, that always begats a nice stable idle, as mentioned above Tony wanted it idling to pass an MOT, which is a different ball game, and one of the reasons for needing closed loop control.

cheers all

bob

 

I have seen on poorly routed pipework, in traffic, an air temp of 50 degrees plus causing up to 5 degrees of ignition to be pulled. I don't need to tell you what this can do to idle speed especially when you include the fan cutting in and out.
Thanks

It isn't so much of a patch as revised settings gained from months of field work. [/QUOTE]

I have also fitted Piper 285's to an Impreza engine, and agree that they aren't the easiest cams to get to idle nicely at Lambda 1.