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Discussion Starter #1
Whats up LT I'm new here and this is my first lotus a 07 exige s. I purchased the car knowing it had issues but as a gear head you buy broken for cheap then fix it and try to enjoy it along the way.

So the main issue is a break up during hard acceleration, it still accelerates just not as fast and you can hear a definitive change in exhaust noise starting at 4500rpm only if engine is under load. Unfortunately won't let me post video for being to large.
Also i can get it to break up before 4500 only if from a cruise I come to complete stop and quickly hard accel ill get a few abrupt sputters then even out right before the 4500 misfire begins.

So things done to combat this
Fresh oil change 5w40 Rotella t6
Intake/exhaust vvt solenoids
Cleaned mesh filters
New MAF. New Delphi coil packs. New denso SK20R11 plugs .031 gap.
Fuel filter. Fuel pressure regulator. New walbro 255 pump.
Lift bolts. Inspected cams for wiping[good]. Getting 10psi max boost

Recently I tested a hard accel while engine was cold and no sputter occured. So to me that sounds like its running lean while at normal operating temperature. So injectors? Tuning? Ecu failure?

Any help is very much appreciated

1268783
 

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Get a bluetooth scanner to see if you can see anything

I would expect a CEL if any significant lean issue

intake/intercooler sealing?
 

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Discussion Starter #3
Get a bluetooth scanner to see if you can see anything

I would expect a CEL if any significant lean issue

intake/intercooler sealing?
Is it unusual for higher end scanners to not connect? The only scanner I can get to connect is a cheapo foxwell. no codes

Also its holding 10psi boost so everythings seems to be sealed
 

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Dreaming of Lotus
2005 Elise Sport Touring
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Are you letting it warm up enough? Is there an aftermarket tune? Is this that super high mileage exige just sold out of arizona?
 

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Did you check spark plugs?

Slather connector tubes in dielectric grease.

Is battery holding a full charge? Battery issues play funny tricks in these cars.

I seem to remember that someone solved a similar problem by finding/replacing a bad fuse. Engine mgmt?
 

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Discussion Starter #6
Are you letting it warm up enough? Is there an aftermarket tune? Is this that super high mileage exige just sold out of arizona?
Yes I always wait for warm up before driving hard. Besides the exception of recently testing acceleration while cold that didn't produce the misfire.
No tune that I know of.
And yes it is. 173k on the body now but luckily motor was replaced at 96k under warranty.
 

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Discussion Starter #7
Did you check spark plugs?

Slather connector tubes in dielectric grease.

Is battery holding a full charge? Battery issues play funny tricks in these cars.

I seem to remember that someone solved a similar problem by finding/replacing a bad fuse. Engine mgmt?
Yes.
Yes.
Battery always has a charge never had a weak start.
And I will go through every fuse and check
 

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Yes.
Yes.
Battery always has a charge never had a weak start.
And I will go through every fuse and check
Just make sure you check the fuses by pulling them out then checking for ~0 resistance across the fuse. Just looking for a burned out fuse isn't always going to show up.

When you pulled the old spark plugs out, what did they look like? Any signs there of how the engine was running? Injectors seem like one of the few other things you haven't checked yet, so I wonder if all four plugs showed similar burning or maybe some cylinders are out of whack.

How are compression and leak down? With the miles, that could be a concern.
 

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Discussion Starter #9 (Edited)
Just make sure you check the fuses by pulling them out then checking for ~0 resistance across the fuse. Just looking for a burned out fuse isn't always going to show up.

When you pulled the old spark plugs out, what did they look like? Any signs there of how the engine was running? Injectors seem like one of the few other things you haven't checked yet, so I wonder if all four plugs showed similar burning or maybe some cylinders are out of whack.

How are compression and leak down? With the miles, that could be a concern.
The motor has 75k miles. Was replaced under warranty. Compression was avg 230 across. And the old plugs didn't look bad to me and attached is how the new ones looked the other day
1268788
 

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Check for shorts on the injectors, check the plug wires are all good.

Get a bluetooth code reader that works. I know this one does for sure

Thinking about it... Does it have a tune trying to change to the high cam and it not mechanically changing at 4500 then the fuel/spark aren't right for the new cam? Trip the cams manually at idle and make sure the engine stalls? Not sure how to check that the cams are actually getting the high signal at 4500 RPM though.
 

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2005 Lotus Elise
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Correct me if Im wrong, but isnt the cam changover for a exige 4500 RPM? And is there something that does not allow the Exige to "go into" second cam if the engine is cold? Being as the cam changeover is less pronounced in a Exige (so ive been told) maybe you do not feel the sputters on a cold engine becuase the second cam is not engaging and the problem lies in something to do with the second cam, quite possibly not the actual cam itself.
 

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Correct me if Im wrong, but wasnt the cam changover for a exige 4500 RPM? And is there something that does not allow the Exige to "go into" second cam if the engine is cold?
No higher then that stock. Im not sure exactly though maybe 5500-6k

Correct
 

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No higher then that stock. Im not sure exactly though maybe 5500-6k
For the regular Exige its 6200 and the Exige S is 4500, still trying to find something official, this will help him narrow down his issue at least.

This is what I can find on this forum about it
"I am talking about the 2nd CAM change. For the Exige its at 6200rpm and for Exige S is at 4500rpm. Like I had mentioned, its very very obvious now. I had a celica GT-S before ... kind of missed the tone! Ha ha ha!!

The HKS intake is problem free this far. Although the box indicated its for Exige year 2000~2004, I have no problem with it. "
 

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You're right sorry I looked at some dyno graphs and the dip is always at 4500. Been too long since I was stock to remember.
 

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You're right sorry I looked at some dyno graphs and the dip is always at 4500. Been too long since I was stock to remember.
Yeah I was trying to find some offical stuff, but if people are saying its engaging then then thats probably what it is :). Now can anyone confirm or deny that the 2nd cam does not come on when the engine is not up to operating temperature? I think if we can confirm that it does NOT come on then we have found the issue to be the 2nd camshaft or something directly related to it.

Could it be the ECU not telling it to engage, but the fuel is coming on like it is engaging, which is causing the stuttering?

From another Member on his Elise, assuming the Exige is more than likely the same
"VVL problem diagnosis

To test the VVL system, put 12V across the OCV at idle (the connector just has two pins and it's a solenoid. If the engine dies, the car went onto lift and the engagement system is working.

Otherwise your ECU isn't telling lift to engage for some reason, and you need to check your cooling system temperature sensor and the oil pressure sensor on the OCV.

If your car keeps running, your lift isn't working for some reason. Take the OCV out and check that the plungers work when 12V is applied.

The ECU won't activate lift if it doesn't think the coolant temp is right (min 72C)

The fuse in the engine bay for VVL and VVT is R6."
 

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Unplug the cam vvt solenoids and see if the behaviour is the same. There we go.

Or just one then the other?
 

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Discussion Starter #17
I'll try running them unplugged and see what happens. I know they activate with 12v because I bench tested before installing
 

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And yes it is. 173k on the body now but luckily motor was replaced at 96k under warranty.
nice looks like it went to the right owner. Best of luck with that. Certainly cooler than the R34 he got out of the sale :D
 

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Discussion Starter #19
Yeah I was trying to find some offical stuff, but if people are saying its engaging then then thats probably what it is :). Now can anyone confirm or deny that the 2nd cam does not come on when the engine is not up to operating temperature? I think if we can confirm that it does NOT come on then we have found the issue to be the 2nd camshaft or something directly related to it.

Could it be the ECU not telling it to engage, but the fuel is coming on like it is engaging, which is causing the stuttering?

From another Member on his Elise, assuming the Exige is more than likely the same
"VVL problem diagnosis

To test the VVL system, put 12V across the OCV at idle (the connector just has two pins and it's a solenoid. If the engine dies, the car went onto lift and the engagement system is working.

Otherwise your ECU isn't telling lift to engage for some reason, and you need to check your cooling system temperature sensor and the oil pressure sensor on the OCV.

If your car keeps running, your lift isn't working for some reason. Take the OCV out and check that the plungers work when 12V is applied.

The ECU won't activate lift if it doesn't think the coolant temp is right (min 72C)

The fuse in the engine bay for VVL and VVT is R6."
Ran car for an errand without intake solenoid and no sputter at 4500! But rev limits at 6200. Im heading to my shop I will trip them both with 12v and test fuses.
 

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Discussion Starter #20
So reporting back. R6 fuse zero resistance along with the others. I tripped both vvt solenoids with 12v while idling and both stalled motor.
So what now?
 
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