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Discussion Starter #1
I recently bought a 2005 Elise from a gentleman in Denver. The car has an aftermarket turbo set up which I had inspected by Ferrari of Denver. I am told that it is a Webb Motorsports set up. I actually flew out and drove it back here to PA. The car runs great and didn't give me any fits other than the coolant hose connecting to the turbo. But now that I'm back I noticed that when I really wind it out and I get around 6.5-7k RPM's the engine starts to miss a good bit. I'm hoping this is a tuning issue. I haven't had it dyno'd and tuned yet. But I was wondering if the lower altitude could play a role perhaps? Looking for a little insight to this issue. Love the car :D and just want to get all the kinks out. Thanks.
 

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Do you still have good boost up there? Perhaps the chamber temps are getting to hot? Cooler plugs, higher octane fuel, or roll back ignition timing?

I'm a big fan of ruling out the easy stuff quickly. I'd clean the plugs or put new ones in. Turbo cars like to run rich so maybe you have some carbon on the plugs and when the chamber pressures get high (high boost & RPM) it gets harder for the plugs to fire. So if you're loosing current through carbon grounding on the side of the plug, it'll show up under those conditions as a stutter. It's worth trying since it's so easy.

Good luck!
 

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Discussion Starter #3
Unfortunately it doesn't have a boost gauge on it. Yet.. But I put a new air filter on last night and it seemed to make it run a little better but didn't do much for the stutter. Was actually planning on doing plugs tomorrow evening, since it's easy and cheap ill take that step next. It's basically flawless up until those higher Rpms. So I'm thinking it's some kind of air/fuel or plugs issue.
 

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Make sure your new plugs are gapped appropriately. (0.28 is typically a good number for a boosted modern engine).

Beyond that i urge you to take it easy until you find the issue. Many of the turbo 2zz Eliges have substandard tuning solutions and can be an accident waiting to happen.

Any more information on which kit this is and most importantly what type of engine management is being used?
 

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Here's a link from this site to look at. Solutions to the hesitation/stutter have been spread out. Some have had it fixed with different solutions and others like me still have it happening.
I'm ready to drive my 2010 Exige260 up someone's ass pretty soon if it doesn't get fixed. Same area of stutter....right around 6K RPM. Tired of repeatedly going to the out-of-town dealer to address this issue over and over again and come up with nothing.....again.
Good luck. Here's the link that may help ya:

http://www.lotustalk.com/forums/f101/engine-hesitation-25451/
 

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Discussion Starter #6 (Edited)
Thanks for the link. It almost seems like a boost leak the way it all of a sudden loses power. I replaced the plugs and gapped them to the previous plugs at about .45 I think. I can try pushing it down to .28 and see if that helps. But as of right now I have a new air filter (old one was disgusting) and new plugs and neither helped a bit.

Mine is the exact same, right at 6-7k it just lets loose and misses/stutters like crazy.

The car is using a Unichip Q ECU. And it happens every single time I hit that area of RPM's in what I believe is all gears.
 

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When you say it breaks up at 6k-7k.. Will it do that if you are lightly accelerating at 6k-7k or only if you are at high load/acceleration at 6k-7k?

In any case definitely gap them smaller. 0.45 is more of a naturally aspirated gap. The spark plugs may very well solve the problem so I would start there.

Unfortunately the Unichip is not a great management solution. Do you have a wideband o2 gauge on the car by chance? You will likely want to monitor your AFR ratio in boost to make sure you aren't going lean as well. There have been a few people on here who have lost engines to poorly tuned turbo setups. While you likely don't need to get rid of the Unichip at this juncture I personally would consider a better solution for the future.
 

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Discussion Starter #8
Not sure why, but neither a boost gauge or air-fuel ratio gauge was ever installed. I'll try the gap, but talking to the previous owner today, I'm thinking it just needs a tune and dyno to this altitude. Unless he's lying to me. Besides the gauges I don't plan on doing any mods. Just want to get it running well and keep it at that point. So if I can avoid swapping the ECU, that would be great. haha.

I'll try accelerating lightly and see if it still does it. I've only seen it do it with the pedal basically buried..

Appreciate the help thus far.

Oh, and one quick question. How tricky is it to get those gauges installed? I've done them on a 3000gt VR-4 but never on any kind of aftermarket turbo set up.
 

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It cant hurt, but check the coilpacks, for little brown burns on the outside, sometimes the sparks can jump through grounding out on the tubes.
 

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Yeah at this point, any car with ECU work that isn't running correctly needs some AFR data. Especially since yours now has a turbo and it didn't come with one :) I think Innovate's LM2 would work if you don't want to permanently install a gauge in your car. Really once it runs good you shouldn't need to keep an eye on it anymore. Naturally if you're going to get it tuned at a shop somewhere then they will get you very close on the dyno, but there is no replacement for street driving the car. Still, it sounds more ignition related but none of us can tell without driving the car of course.

Another fun thing to try is an OBD2 reader. I have one for my Android phone with the Torque application and it isn't the best but it is cool to see all the real-time data from your car, including... Wait for it... lambda and timing advance! :) I don't know how an aftermarket ECU will jive with it though.
 

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Yeah at this point, any car with ECU work that isn't running correctly needs some AFR data. Especially since yours now has a turbo and it didn't come with one :) I think Innovate's LM2 would work if you don't want to permanently install a gauge in your car. Really once it runs good you shouldn't need to keep an eye on it anymore. Naturally if you're going to get it tuned at a shop somewhere then they will get you very close on the dyno, but there is no replacement for street driving the car. Still, it sounds more ignition related but none of us can tell without driving the car of course.
Unfortunately because the unichip is a piggyback it has been reported that unless you are careful with the fuel trims the ECU will eventually learn and apply those trims in open loop and your AFR can change over time. So I wouldn't just tune with a piggyback on the stock ECU and then remove the wideband instrumentation, as the fueling may change over time and you will probably want to keep an eye on it.

Another fun thing to try is an OBD2 reader. I have one for my Android phone with the Torque application and it isn't the best but it is cool to see all the real-time data from your car, including... Wait for it... lambda and timing advance! :) I don't know how an aftermarket ECU will jive with it though.
Torque is a great app... especially for the money!

However while the timing advance is something that is likely accurate the "lambda" is not. Because the stock ECU only has access to a narrowband o2 sensor the lambda you read at WOT can not be trusted, as it is only accurate around stoich. You will need a real wideband sensor/gauge for an accurate lambda reading under rich conditions (WOT).
 

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Discussion Starter #12
I did regap the plugs today. Haven't had a chance to drive it, but the coil packs do have a brown powdery residue on them. As well as the shafts that house the plugs.

Looks like I might go the route of having it tuned after I knock these small things out of the way first. After talking to Ferrari of Denver and the previous owner, It seems like the altitude difference between Denver and south central PA could be the reason the issue is all of a sudden surfacing.

Do I need a special cable with the torque app?
 

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It only does it to me at med-high acceleration. Just peddling it through the rpm range is ok. Only when I really want it not to work and go fast, it rears its head. Kinda sounds like it hits the rev limiter.
My dealership replaced the fan control module and no go. They also replaced the engine wire harness and still no dice. I had it with this. Sucks the enjoyment right out of the car.
Welcome to the unfortunate nightmare.
 

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I did regap the plugs today. Haven't had a chance to drive it, but the coil packs do have a brown powdery residue on them. As well as the shafts that house the plugs.

Looks like I might go the route of having it tuned after I knock these small things out of the way first. After talking to Ferrari of Denver and the previous owner, It seems like the altitude difference between Denver and south central PA could be the reason the issue is all of a sudden surfacing.

Do I need a special cable with the torque app?
Yes you will need a bluetooth OBD-II cable.
 

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It cant hurt, but check the coilpacks, for little brown burns on the outside, sometimes the sparks can jump through grounding out on the tubes.
+1 on the coil packs. I had similar behavior on my NA car. I was ready to replace the clutch when I decided to replace the coil packs after seeing the OE coil packs exhibiting the brown burn-through marks and hearing the arcing. My new, after market coil packs have been slathered in dielectric grease to prevent future problems. So far, so good after about 5,000 miles.
 

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Discussion Starter #17
Until I get a chance to get in there and rip things apart I have no clue whats on it mechanically just yet. And is it true that the engine has to be really hot before it will let you take it over 6k?? Because I read this somewhere and after driving last night It did it once early in the drive, then I wound 1st-3rd gear out later in the drive and had no issue. I did put dielectric grease on the coil-packs. Previous times when it acted up I drove it for a few minutes before I ripped on it and it still did it, but maybe not long enough? If me not letting the car get hot enough is all it is I'm going to feel like a real idiot..
 

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i believe the ECU needs to see a water temp in the 160's before it will let you vvt. My practice is to let the water temp stabilize at 186 degrees, then wait another 5 minutes to allow the oil to get really hot. Then i can engage the supercharger and warp drive.
If you try and vvt (go past 6k rpm) before the ecu sees those 160's it will bounce off 6k, stutter, then let you drive under 6k rpm until warm. Don't ask me how i know. You can screw up the motor if you don't let the oil get hot. And the oil temp will lag the water temp, which is why i wait a little longer. I hear you want the oil temp in the 250's to really give you the protection and performance you need.
 

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Discussion Starter #19
Wow. That's really good information to know. Apparently that's all it was then. I just took it out this morning and got te temp up to 183 and she ran just fine. Thanks so much for the help! Glad it wasn't actually a major issue. Still going to have it tuned and try to get some type of boost and air fuel gauge.
 
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