[Lambostuff]

Hi Everyone, I have spend some time trying to find other posts with similar problems and although I found some, none were void of CELs and Code's like mine..

I JUST bought the car 2 weeks ago had about 20K miles on it and it seemed to be trouble free the first 100 miles but now at nearly every speed and gear the car will lose power out of nowhere and then it "kicks" back in after a few seconds if I flutter the throttle.. then I am good for another 2 or 4 minutes.. I am getting concerned as it seems to be getting worse. When stopped, it sometimes will idle very low almost like it is getting ready to die.

I have no Check Engine Lights and there are no codes on the OBD Scan Tool.

Any Suggestions on where to look first?

Thanks
Jason

 

[waydui]

Hi Jason,
First, congrats on the new car!

Your problems could be a number of things. Bad gas comes to mind first. Did you fill up recently?

Also, I would check the throttle cable linkage. 2005 models don't have DBW throttle, so the cable can be misadjusted or the butterfly plate sticking. A good cleaning of the throttle body would always help.

Are plugs clean? Air filter clean?

Low idle was always a problem on mine, but it never actually stalled.

I'm in Ohio too. Depending on where you are, I can check it out.

Good luck.

Regards,
Wayne

Hi Everyone, I have spend some time trying to find other posts with similar problems and although I found some, none were void of CELs and Code's like mine..

I JUST bought the car 2 weeks ago had about 20K miles on it and it seemed to be trouble free the first 100 miles but now at nearly every speed and gear the car will lose power out of nowhere and then it "kicks" back in after a few seconds if I flutter the throttle.. then I am good for another 2 or 4 minutes.. I am getting concerned as it seems to be getting worse. When stopped, it sometimes will idle very low almost like it is getting ready to die.

I have no Check Engine Lights and there are no codes on the OBD Scan Tool.

Any Suggestions on where to look first?

Thanks
Jason

 

[Lambostuff]

Thanks for the reply,,

I have over 4 fill up's since I got it and all with Premo gas so I don't think that is it..

I'll check the other things you mentioned right now....

I'm around the Dayton area, it would be great to talk to you... my skills are in other European cars.

Thanks
Jason

 

[spectre]

You know I had a similar issue today I think. I was driving on the highway and about 3700rpm and it felt like a flutter in power than it stopped and came back. Then engine light came on. As that happened though I heard a noise almost like a release of pressure. So I pulled over and looked in the engine bay and nothing looked or sounded different so I checked the gas cap as I recently filled the tank and the gas cap was not on completely so I thought maybe the pressure caused the cap to release. My gas cap has never been right on my car. Anyway, it was idling fine. I shut it down and let it sit a few minutes then started it back up and the check engine light was still on but nothing sounded off. Started driving again and it did the same thing...

 

[Robissimo]

Eerily similar to my current situation: 2005, 21k miles, no codes, no cel. Changed plugs and air filter. no change. After three tank refills, and continued intermittent power loss, I added a some fuel additive (Techron) which did not have an immediate effect. Three days later, I took it to a mechanic who found and cleaned some schmutz on the ecu connectors. He's been unable to reproduce the problem since. Until I get the car back, I would not say for certain that its fixed.


After hours of searching SELOC, Monkey and LotusTalk I came up with the following as possible causes:

bad gas
dirty MAF sensor ( unlikely if you are using stock air intake )
bad oxygen sensors
spark plug(s) gone bad
dirty air filter
dirty throttle body
bad engine wiring harness
vacuum leak
fuel pump dying
fuel pickup clogged by baffling sealant.

 

[Lambostuff]

Thanks for the input, I'll have to add each one of those to my "to do" check list. At least I have a starting point.. what's the secret on getting access to the filter and spark plugs?

 

[spectre]

Well, my check engine light has not gone away and added new fuel. I was hoping it was just the gas cap not on correctly or a bad tank of gas. Im not sure how many cycles it takes to go off or what. May have to take it into the dealer. Odd thing is that the car seems to run ok...if anything maybe a little pulse in 5th gear at freeway speeds.

 

[Lambostuff]

I am finding a small "untested" correlation between the amount of gas left in the tank and my problem. I think that I am 90% sure that it is fuel delivery problem. When I hit 1 to 2 bars of gas left, I start having this problem every time I drive. After a fill up, the problem went away. I just filled up this morning and the drive to work was flawless... I'll keep everyone posted.

New to the Lotus experience, however I would think you should be able to clear the code (CEL) with any ODB scan tool

 

[...m...]

...the stock fuel tank baffles generally have a very limited lifespan due to adhesive breaking down upon contact with fuel...excepting fuel starvation in a high-lateral-force track environment, most of us just live with it with no major problems, as the fuel tank's a pain to replace, but certainly it's possible for some of that tank debris to block the pickup, which sounds correlative with your symptoms...

 

[charliex]

sounds like an electrical issue (power loss)

the gunk on the ecu pins is a common problem.

could be a leak, but unless its idlling badly most of the the time, less likely http://www.lotustalk.com/forums/f101/diagnosing-vacuum-leak-67632/

 

[Lambostuff]

Well the fuel tank level has nothing to do with it.. I am going on a gut feeling here based on a similar experience on another car, but it really is sounding like a fuel filter that is getting blocked.. Letting the car sit and rest gives particulates the time to come away from the filter screens and then it runs great until after about 5 minutes...

Anyways I am plunking down around $500 bucks and ordering a new fuel pump and filters..

Now my new problem is the dealership says he does not see any filters other than the one INSIDE the tank to replace, and he sent me the PDF of the manual and indeed there are no filters other than the one INSIDE the tank... Now looking at the service manual, it shows a filter that is OUTSIDE the tank.. anyone have a part number as to this "outside-the-tank" filter?

THANKS!

 

[waydui]

Now my new problem is the dealership says he does not see any filters other than the one INSIDE the tank to replace, and he sent me the PDF of the manual and indeed there are no filters other than the one INSIDE the tank... Now looking at the service manual, it shows a filter that is OUTSIDE the tank.. anyone have a part number as to this "outside-the-tank" filter?

I have checked the Parts Manual and found the "in-the-tank" filter (Part #A120L6001S).

I also checked the Fuel System Section of the Service Manual and I do NOT find an external filter for an '05 Elise. Where do you see this filter?

Maybe they updated the manual and mine doesn't show it.

Regards,
Wayne

 

[Robissimo]

I got my car back two weeks ago and now runs perfectly. I would highly recommend you pull the ecu and check the contacts before you spend any money.

 

[Whiskey]

I had a weird surging acceleration problem once and found it to be an intermittently failing "by-pass valve actuator" on my supercharger. I first noticed a decrease in MPG. Upon engine bay inspection I noticed a faint, almost balloon leak-like sound when I manually blipped the throttle. The car's reaction was not pleasant when it finally failed and a rich condition occurred, but it runs great once the valve was replaced.

This incident prompted me to purchase a DashDAQ to monitor the car whenever something else ever came up. Because of having the DashDAQ I found an O2 sensor problem with it recently and haven't had to go to the dealer 70 miles away in Columbus.

I don't know if you have an aftermarket supercharger on the 05'. If there is no SC then forget about the by-pass valve. But, an OBDII monitor is useful to own.

 

[spectre]

I went to autozone and used the OBDII and my code was po171 engine bank lean, so in it goes...

 

[Lifespan]

I am having a similar problem on my 05 Elise, but it only appears at low throttle. When I give it steady, light throttle, it chugs/surges/hesitates pretty clearly and is especially bad when the car is cold. I have no check engine light, but it seems to be becoming more common as time goes on. When it occurs, I don't notice any fluctuation in the tach. Gas shouldn't be an issue either. Any idea?