normal.
when you start it let it idle for at least 20 seconds (ECU reasons) and then rev it up to around 3000 and let it warm up a little depending on how cold it is.

then drive it easy till the temp shows on the inst. pan.

---
it is just cold and needs to warm up. nothing new or major.

 

......+1...1000...

 

Yeah it kind of feels sluggish then all of sudden it will accelerate a little harder with no change in throttle input. :tadts:

I never notice it after I pull out of my neighborhood (2 stops), and I let my engine warm up for at least 20 seconds everytime I drive it

 

that'a normal behavior.

let us know if your car stalls when crawling / slipping the clutch, like in a parking lot. a few of them do that, including mine. that, is not normal.

 

:tadts: I was suprised by this the first time I drove an Elise, but every single one I have driven since does it too. Some cars (my 540 included) stumble a bit when cold. I just think of them the same way I act in the morning. I don't wake easily, and I'm cranky, but once I'm up I'm ready to go.

 

You should do this for ANY high reving modern motor with tight engine tolerances. Today's motors are built to tolerances that allow the engine parts to work well together once the motor is at full operating temperature. So when it is cold, and the metal parts have not expanded, things don't quite work right.

Let the car warm a bit before you drive, and then keep the rpms below 4500 rpm, but also not much below 3000 rpm (you also do not want to lug the engine) until the car has fully warmed up. I actually do not agree with the advice that you should wait until the coolant temp shows up before you hammer it. You should wait until the OIL is up to temp before you hammer it. We do not have an oil temp gauge, but you can get a pretty good idea by waiting at least 10 minutes after you start the car before you start pushing it, and you might even want to wait about 15 before redlining it. And in the winter, wait a little bit longer still. Or, you can use the water temp, but wait until it has reached its normal temp before you push it; I think this is a much better indicator that the oil temp is where it should be.

I realize that the ECU restricts your RPM to 6000 (I think) until the car shows temperature, and then it allows full RPM. But this is just to make sure that a total idiot who does not know anything about engine warm-up does not damage the motor by starting it and immediately redlining it. When the car shows temperature, I think it is a decent indicator that the oil is getting up to temp, but it is not the best measure. It shows temp at 158.

I actually wait until the car gets up to at least 180 on the coolent temp before I go over 4500 RPM, and then wait a little longer for any real high revs. This is much easier to do in an Exige S because you are always in the power band anyway.

Oh, and all of this is only after a cold start when the car has been sitting over night or for days. If you run to the store, and then come back out in 20 minutes, then you really do not have to worry too much. I would still watch things a bit, but in this case the car should be right back where it was in a minute or two, or no time on a hot summer day. Even 4 hours of sitting on a summer day will allow the car to get up to temp very fast.

Stephen

 

+1 I do not hammer it until I think the oil gets hot either. 15-20 min.
Stephen is right on

 

My '05 runs smooth, I've never noticed any sputtering or anything like that (except for the 'stall when stopped' feature early in its life that an ECU reflash seems to have fixed). But then, I do let it warm up for 20-30 seconds before starting a drive.

 

you might want to check for a newer version of the ecu software, it always suprises me just how many ecu's i see with the original software.

 

Thanks for all the quick replys. That definitely puts my mind at ease. charliex said something about getting the software in the ECU upgraded. Would this be a good idea to have done anyway even if I'm not having problems?

 

Probably it is best to get the latest, but Charlie is the expert on that. He is also willing to sell you his version along with a supercharger. I really like that option the best!

 

TADTS. The underlying reason is emissions. To pass the EPA cold start test it is critical that the cat is lit off as soon as possible (note that this is an OE test - not at all the same as the smog station tests - the exhaust gas is actually collected in bags to be tested). To heat the cat quickly the ECU retards the ignition, bascially as much as possible, and then a little bit more. This causes the engine to stumble and run quite poorly. Retarding the ignition reduces peak cylinder temperatures, and thereofe NOx emissions, and also increases exhaust gas temperature, putting more heat into the cat. As a secondary effect, the engine warms up quicker too. The downside is that for the first 5 minutes or so from a cold start you get poor running and bad fuel economy.

 

the updated tune affects the dashpots for coming off power to idle/low rpm so it helps with that stumbling and some of the rougher running with some fuel map tweaks, the one where you pull up harder at the stop sign and the engine cuts out, not the cold engine, dstevens knows what he's on about.

 

Ok a little update on this. I was driving last night (45 minute drive) and the engine was warmed and still sputtering almost every time I would take my foot off the accelerator but still have the car in gear. It's like a crazy, jarring and jerking like dropping the clutch in first gear but it did it in 3rd 4th and 5th gear. Engine revs were like 3k.

Does that still sound like a need a software update? Or is there maybe something else going on here.

 

Ok got my Lotus back from the shop yesterday and the problem was 2 things.
1. the car needed software updates. (thanks charlie)
2. someone stole my gas cap and some moisture got in there and was causing the engine to run rough and jerk like that.

 

difficult to say, but it doesn't sound right, the ecu update solves a couple of small issues, on the first revs the emissions related sputtering was a bit worse, and they cleaned it up a bit, the second problem was related to the dropping too low on the RPM on braking/stopping at a corner issues, as well as some rough running, and by rough i mean a bit wobbly here and there on low rpm , not sounding like terminally ill moose.

It doesn't sound like it, but are you talking about the exhaust tone changing when you take you foot off the acelerator or drop the clutch, and theres a burbling/popping noise going on ? that's nomal too and depends on the exhaust.

something sounds amiss though, i doubt its an ecu related issue.

could be a bad tank of gas, but best to take it into a mechanic.

 

No not just the burbling sounds of the engine slowing but like the car is physically jerking hard when i take my foot off the accelerator and let the engine slow itself.

I'm taking it to the shop tomorrow for some other issues, I'm just trying to get a better idea of what could be wrong.

 

charliex may be on to something with a bad tank of gas. What your car is doing sounds like what happened to me years back with another car and a gas station I stopped going to. I wouldn't drive it around until the mechanic looks at it though. You never know, it might be something simple like a loose plug wire. It doesn't sound anything like my 05 ever has done warm or cold.

 

My car always ran smooth even when cold, up until the day my problems began. After that VERY crappy cold-start running, lasting a good three to five minutes. Have been through at least ten tanks of gas since then, from various stations, with no improvement. Have had the ECM updated, and indeed replaced, with no improvement.

xtn