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Discussion Starter #1 (Edited)
So I dropped off the Exige today at a local shop to fix my leaking sandwich plate issue. They swapped the fittings to BSP to -10AN fittings and everything was good to go. This was among the very last of the mods I had to do to take the car to the track with good peace of mind. (I may throw a surge tank and a baffled oil pan on there for good measure.) They finished up the repair, I take the top off, and jump in to drive home in the amazing Seattle weather (no sarcasm, it was amazing today, just like it has been for the past month :D). Then something really... shi tty happens.

I am cruising along on 520 at about 60mph when suddenly all power is lost.

No hesitation. No stumbling. No slow loss of power. The revs just drop to zero.

This is right before rush hour so I guess thank gawd for that cuz I can pull off to where the carpool lane is just opening up and get out of everyone's way. AND if it had happened a little bit farther along I would have clogged up the two lane bridge and been "that guy" that caused a huge backup Friday afternoon. But since it WASN'T rush hour, everyone was blowing past me in my tiny fiberglass car. Sheeeit was scary.

I turn the car off, then back on, and start it. Car hesitates then fires up, engine revs to 4k rpms and dies immediately. Fans kick on full blast. I've experienced this multiple times, the fault codes always read the same three ones. Something about the fuel circuit "a" being left open, the throttle actuator out of tolerance, forced engine shut down. This is most definitely related to the throttle body. Ok, so I shut her down again, wait a bit then fire her back up. This time engine turns over and idles fine. I give the car a bit of throttle, slowly revving it up to about 4k where it quickly dies without notice.

At this point I'm pretty pissed. I thought I had gotten everything on this car nipped and tucked. But then THIS happens.

I call the shop and they send a flatbed out and I get towed back. Service manager hypothesizes that it may be the throttle body finally taking a crap and giving up the ghost. Back at the shop I started it up, it did its whole high rpm then dying bit, which was cute, but luckily it started up the second time ok. I drove it around the parking lot without incident. I needn't say that I wasn't confident or comfortable driving it home. (But I guess I just DID say... herr herr)

So now it sits in the shop waiting for them to troubleshoot it. What do you guys think it could be? I'm willing to bet it's the throttle body moving on its last legs. It's been giving me issues since the week I brought it home. ChronosWS and I have nearly the exact same setup now but his car exhibits none of the problems mine does.

I called the stealership and checked to see how much a new throttle body for a 2006 Exige is and was pleasantly surprised. I had always thought it would be something really expensive, like $900 or something. But it was actually $1,845. Oh, wait, did I say "pleasantly"? What I really meant to say was something that would express a sentiment closer to being furiously butt-raped in a filthy truck stop restroom. Perhaps the restroom stench has graduated beyond stench and into war crimes territory. Yeah....

At any rate, hopefully they can test the throttle body and see if there's anything wrong with it electronically. If there is, I need to source a new DBW throttle body somewhere. Does anyone know if a throttle body from a Celica would fit? Or if there is anyone selling a used one? Anything would be preferable to having to pay nearly $2000 for a new one.

Thanks, guys, and sorry for the long, ranty post. I was just pretty pissed about everything today.
 

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gotta pay to play.... hate working on cars because of this sometimes haha. Hopefully you can find a good solution for this!
 

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Discussion Starter #6
My AC wasn't on. I have heard of this issue and I have experienced the engine cutting out and outright dying before. Fortunately, I can cross that off the list as I've had the updated relay installed and the AC now works fine.
 

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Your issue could be many things, you'll have to start with what you know and eliminate one item at a time. Error codes can be a hint, but they could also be triggered by some other event/failure.

As to your PM, I'm not sure about moving from DBW to DBC on a stock ECU ... I've never done it as I have an EFI ECU. You'll need to check in with the folks that re-program the stock ECU.

First you need to look into what this means
fuel circuit "a" being left open
The DBW pedal is a GM unit (on my 07 Exige S) ... cheap, cheesy plastic (I've got better quality pedals I use for simulated racing on my PC) -- opening it up is tricky as you don't want to break the plastic retainers -- but you can try and clean the contacts and arm inside once opened.

Next stop is to check the throttle actuator and make sure you see the throttle flap move to a full 90 smoothly. The DBW throttle bodies are not cheap, I sold mine a few years back and gave someone a great bargain!

Here are some opitions for pedal replacement: Lokar DBW -- you want to get the GM unit as it "should be" the same (you will have to fabricate your own mounts to work with it): GM Unit DBW-GM01 or DBM-GM02 BUT, I would call them first to confirm it will work with a Lotus GM DBW unit. The basic idea is that constant voltage is applied and the potentiometer resists the voltage as output.

I never was a fan of the Lotus DBW setup and the traction control system isn't programmable ... hence my move to DBC. Now DBC has it's own issues too, but they are just so much easier to maintain even if not as flexible.

If you move to an EFI ECU (which ironically isn't much more than a new DBW Throttle body part you listed from Lotus .. who BTW seem to have added $1000 to the same unit Toyota provide for $876).

You can get the Toyota DBW throttle body for $876.58 here Celica GT-S DBW throttle body ... Toyota celica GT-S switched to DBW in 2003.

But like I said, first thing to do is find out which error code happened first ... as with software engineering, one error can trigger many other errors (which in most cases are just a byproducts of the first "real" error).

Rob
 

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Discussion Starter #8
Well, the car is still at the shop, they are testing the throttle body + wiring to try and find out what is going on with it. Does anyone have a wiring diagram of the pertinent parts? (Anything related to the throttle body...)
 

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Discussion Starter #9
Here are some opitions for pedal replacement: Lokar DBW -- you want to get the GM unit as it "should be" the same (you will have to fabricate your own mounts to work with it): GM Unit DBW-GM01 or DBM-GM02 BUT, I would call them first to confirm it will work with a Lotus GM DBW unit. The basic idea is that constant voltage is applied and the potentiometer resists the voltage as output.

I never was a fan of the Lotus DBW setup and the traction control system isn't programmable ... hence my move to DBC. Now DBC has it's own issues too, but they are just so much easier to maintain even if not as flexible.
Will the Lokar dbw setup eliminate that "delay" or "lag" when you stab the throttle? I'm pretty sure I'm not the only one who thinks the stock Lotus setup is not really that responsive...
 

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There are screws inside the tb that become loose. The screws old down a sensor or something. You can remove the cover or shake it and listen for rattle.
 

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Will the Lokar dbw setup eliminate that "delay" or "lag" when you stab the throttle? I'm pretty sure I'm not the only one who thinks the stock Lotus setup is not really that responsive...
It's not the pedal that's the complete problem, the servo on the TB it self takes about 150ms to open 100% from the time it gets the signal to open...
I don't know of a workaround for that one.

PM me your email addy, I'll boost you the 06 schematic.
 

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I Think it's the pedal as well.. Replaced about 10 on gm models.. That's also what I read on other problems that sounded just like yours butters.. (exiges and Elise's )..
 

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There is a wire diagram to download at the boe website ' one of the sponsors
 

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Discussion Starter #14
I Think it's the pedal as well.. Replaced about 10 on gm models.. That's also what I read on other problems that sounded just like yours butters.. (exiges and Elise's )..
Yeah, I would love it if I could rev-match as well in the Exige as I can in my '96 Miata. That pedal has zero lag and is super responsive. The Exige, in comparison, has a fair bit of lag to it. Here's hoping that changing out the throttle body will alleviate some (or most, hopefully) of it.
 
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