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Discussion Starter #1 (Edited)
So yesterday I put on my '07 Exige S: Larini De-Cat pipe, Arqray titanium exhaust.

Now when idling the car will idle okay for maybe 10 seconds around 1k rpm, then it will dip to maybe 600-500, then shoot up to 2k (almost dying). Then right after that it will just stall. Doesn't matter if I'm in gear or not.

Anyone ever have this problem before? I did a search but maybe I wasn't looking for the right key words!

Thanks

I should add that prior to these mods I never once had an issue with this. I read somewhere that the ECU takes some time to adjust? Could this be it?
 

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hell, i didn't do a single mod to mine and it did the same thing.

i wonder if it's the same issue as our stock cars, which was either an ECU update or a vacuum leak in the intake (which was my issue).
 

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I had a similar issue when I had a loud exhaust on my car. The checklight would come on and the car would die at idle sometimes. Since I changed everything back to the stock setting and got an ECU update the problem has been solved. I wonder if this means that anyone who changes their exhaust will have a problem, but it also looks like not everyone is experiencing this, so I'm sure what to read of this. The ECU does some relearning so I'd give it a couple of weeks and then decide what to do.
 

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Discussion Starter #6
yea I de-cat'ed mine too so thats probably what is causing it. I absolutely love the sound now but that's going to be really annoying to just keep blipping the throttle!

O2 sensors I reconnected into the new larini pipe
 

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shay2nak
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i've got a 3" 2B zaust, green filter and my car had idling problems before and after these mods...but since Gotham, the idle is so smooth. no probs
 

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Discussion Starter #8
i've got a 3" 2B zaust, green filter and my car had idling problems before and after these mods...but since Gotham, the idle is so smooth. no probs
thats good to know as I'm planning on doing the gotham tune soon. Did you say anything to Charlie about your idling issue or did you just ship away your ECU?

thanks
 

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What I've learned after doing performance mods on other cars (my Elise is still stock intake/exhaust) is to reset the ECU after modding.

Disconnecting the battery for a few hours might reset the ECU. Or you can try Charlie's ECU reset:

1. Switch the ignition to ACC ( not the engine ) , get to step 2 within 10 seconds
2. Press the throttle to the floor This sequence must be done within 20 seconds
3. Let the throttle go
4. Press the throttle to the floor
5. Let the throttle go
6. Press the throttle to the floor
7. Let the throttle go
8. Wait upto 20 seconds
9. The check engine light should flash once

You must depress the throttle to over 70%, and then it must be let go to under 30%

Do not start the engine during that period, if the check engine flashed, the ECU is reset, if the engine is started during any part of this sequence, the learn tables will not be reset!
 

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Discussion Starter #10
What I've learned after doing performance mods on other cars (my Elise is still stock intake/exhaust) is to reset the ECU after modding.

Disconnecting the battery for a few hours might reset the ECU. Or you can try Charlie's ECU reset:

1. Switch the ignition to ACC ( not the engine ) , get to step 2 within 10 seconds
2. Press the throttle to the floor This sequence must be done within 20 seconds
3. Let the throttle go
4. Press the throttle to the floor
5. Let the throttle go
6. Press the throttle to the floor
7. Let the throttle go
8. Wait upto 20 seconds
9. The check engine light should flash once

You must depress the throttle to over 70%, and then it must be let go to under 30%

Do not start the engine during that period, if the check engine flashed, the ECU is reset, if the engine is started during any part of this sequence, the learn tables will not be reset!
I got the parts from sector 111 and spoke with them on the phone this morning. They told me to disconnect battery for 30 min, let the car idle for 15min, drive it for 5-10min, then let it idle again for 10 min.

Excuse my ignorance but what position of the ignition is ACC? That reset would be so much faster!
 

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shay2nak
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thats good to know as I'm planning on doing the gotham tune soon. Did you say anything to Charlie about your idling issue or did you just ship away your ECU?

thanks
nope, just sent the ECU to him.
 

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My car ran pretty rough also after installing a silenced decat. I reset my ECU and that helped, but it still was pretty rough and tended to swing wildly on idle. However, the problem did slowly go away after about a week so I'm pretty sure it was an ECU learning issue.
 

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Discussion Starter #13
Did an ECU reset today and still have issues with the idle. I'm hoping my car will act like lancer360's and improve over time, but I noticed something today that was interesting.

Starting the car up from cold the idle is fine, no problems whatsoever. It is just when the engine gets warmer that the idle starts swinging up and down and then stalls. What could be the cause of this??
 

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Starting the car up from cold the idle is fine, no problems whatsoever. It is just when the engine gets warmer that the idle starts swinging up and down and then stalls. What could be the cause of this??
Sounds like a stuck throttle body. But, what would be the odds that happened at the exact same time you did your mod.
 

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I have the same issues -- the car doesn't seem to be very tolerant of modifications. But I'm using FF's setup and the stock ECU is only used for speedo and a few other basic functions as the stand alone EFI unit controls the rest.

This problem is certainly "mysterious" and is not always present. FF spent some time trying to resolve this problem and appeared they did, but unfortunately a few days later the problem returned. About the only consistant observation I've made is that the harder I driver the car, the less like I get into idle oscilation issues when I'm at a stop.

Casey at FF had mentioned something about Lotus not using a "standard" idle setup -- unfortunately I don't really know what exactly that means.

I also have the stalls when hard braking to a stop. I was told this could be poor gas, so I run 96 octane or 100 octane and the problem persists -- so I've eleminated the bad gasoline theory. This particular problem existed from day one when the car was bone stock.

Not sure what exactly is going on with these cars, but I really would like to find out and Lotus aren't being very helpful (pre or post modifications).

For those having this problem, do you all have the AC option installed?

Could this also be an oil viscosity issue that is causing problems with the VVT system?

Rob
 

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this thread needs a bump
to all the noobies that dont know about idle stuff.
 

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there's a TSB from lotus regarding the idle issue.
that is to bump the idle screw up a ta.

another thing is to keep the IACV clean. (also, change that gasket. it's very cheap.)

specs :
800 rpm
+/- 50 RPM

good luck, good idling.
 

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IACV? Got a pic of that and it's location? Would seem strange this device is immediately bad off the show room floor and on cars with < 6,000 miles on them.

Are you sure there is an idle screw on the throttle by wire cars? I can't seem to find one -- thought this was all controlled thru the ECU?

My car will die under moderate braking while coming out of 3rd into neutral.

But at this point I'm willing to check anything and everything since Lotus reps are completely unresponsive.
 

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Discussion Starter #20
With the Larini De-Cat, the only way I was able to fix the idle was to cut the springs down 2 coils on the spring loaded screws. Before the fix and the Gotham 265 tune the exhaust would throw a code but now I don't have that problem.
 
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