The Lotus Cars Community banner

1 - 16 of 16 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
Hey guys! I just finished installing a Forcefed 275 on my 05 Elise (got it at a good price from WireWheel). The main issue I am having is due to the idle. The car idles at 2800rpm. I believe this is due to the fact that the EFI ECU is probably off of a newer lotus with a drive by wire system. I tried messing with all of the idle settings and made sure that the throttle sensor is reading low or no throttle at idle. (It is showing up at like 4 degrees). I lowered the little screw so the throttle is as closed as it can be yet it still idles at 2800rpm. Anyone have any advice?

Additionally I believe I have the vaccum lines correctly ran for the turbo, but I wanted to make sure. Does anyone have a rough diagram of how those hoses should be ran? I have the install how to and it was very vague about those lines.

Thanks for the help!

-Saxon
 

·
Registered
Joined
·
4,406 Posts
If you the ECU has wiring for a dedicated IAC then it isn't for an 06+ since the IAC is used in lieu of an electronic throttle. What's the min throttle angle for triggering idle?
 

·
Registered
Joined
·
12 Posts
Discussion Starter #5
The min angle I have is 4. I was reading the EFI setup PDF and it said to set a couple values to 1.5 more than that value so I adjusted them in the tune, however it did not lower my idle . I even adjusted the multiplier or whatever they refered to it as by 10. It seemed nothing I changed for the idle settings on the tune made a difference to the way the car was idling.
 

·
Registered
Joined
·
4,406 Posts
It sounds like you aren't getting the idle flag. So if the smallest throttle angle you are getting is 4° then you want your min throttle for idle to be 5°+ otherwise it'll never go "oh look, I need to go to idle mode now"
 

·
Registered
Joined
·
4,406 Posts
One more thing - what's your idle speed with the IAC disconnected? If my memory is accurate, that shouldn't be anywhere close to 3k, so if it still is then that's gotta be a vacuum leak.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #9
Yes, thank you. That was the PDF I used to set all of the initial values before I turned it on. I set it to 5.5 and it didn't seem to matter much. I initially turned the car over with the tune that came with the kit because it was the ECU that was used in conjunction with the turbo kit I bought. (Pulled off a wrecked car). I assumed it should be in the ball-park since it's the same turbo kit and same engine.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #10
I'll check my idle speed with it disconnected when I get home. The weird part is that it idles just fine without the standalone. As soon as I connect everything over to it, I get that weird high idle.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #11
I'm thinking that I might have the vacuum lines ran incorrectly, but I have not found a good source online to show me how it should be.
 

·
Registered
Joined
·
124 Posts
Have you verified the TPS is working and is setup correctly?
Which vacuum lines?

Sent from my SM-G950U using Tapatalk
 

·
Registered
Joined
·
4,406 Posts
Yes, thank you. That was the PDF I used to set all of the initial values before I turned it on. I set it to 5.5 and it didn't seem to matter much. I initially turned the car over with the tune that came with the kit because it was the ECU that was used in conjunction with the turbo kit I bought. (Pulled off a wrecked car). I assumed it should be in the ball-park since it's the same turbo kit and same engine.
Did you also raise the max rpm ceiling? If you follow that PDF exactly then you'd set the limit to something around the low 2000s, so with an idle currently at 2,800 it won't set the idle flag, whatever the throttle position. Currently you'll need the ceiling to be over 2,800 to trigger the idle flag, assuming there isn't a hardware issue like a vacuum line (and sorry, can't help you there)
 

·
Registered
Joined
·
12 Posts
Discussion Starter #14
@cyow5 , I unplugged my iac and tadaaa. The car's idle dropped to 1200 or so like a normal car. I know the iac worked fine before switching over to the new ECU. Any thoughts on why it would do that?

Thank you for all of your help. I really appreciate it.
 

·
Registered
Joined
·
4,406 Posts
@cyow5 , I unplugged my iac and tadaaa. The car's idle dropped to 1200 or so like a normal car. I know the iac worked fine before switching over to the new ECU. Any thoughts on why it would do that?

Thank you for all of your help. I really appreciate it.
Progress! My guess is there is some confusion between the ECU and the hardware on which ways are "up" and "down". Might be as simple as swapping +/- on the IAC but you'll want to santiy-check that before frying anything.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #16
So I played around with vacuum lines and moving around wires etc with no luck. I know this IAC valve worked fine on the motor before I put installed the new ECU. The new wiring harness has the same 3 cable pinout as the old harness for the iac plug. I would just leave it unplugged but the car tends to stall after getting on it and letting off the throttle. I have made all of the adjustments using the EFI tuning software. The throttle level is not the issue.

Ugh I'm lost. Any ideas?

Thanks.
 
1 - 16 of 16 Posts
Top