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Hesitant starting when cold after supercharger install

7K views 37 replies 11 participants last post by  brandobot89 
#1 · (Edited)
Hesitant starting when cold after supercharger install (with video)

I'm noticing the car seems to hesitant at starting when sitting for 5+ hours after i had a factory lotus supercharger installed.

It use to crank for a second when holding the Engine On button, then start right up. Now it cranks for about 3-4 on cold starts and sounds really weak before starting up.

Battery is always on a tender. I also notice that if the engine is warmed up and I start the car, it'll crank the usual 1 second and start right up.

Added video here. A little hard to hear, but when it does fire up, the engine sounds weak. You can see the RPM bouncing around the 500 rpm range before it finally gets up to ~1000.


Changes since I started noticing this:
-Supercharger install
-injectors
-spark plugs
-re-tuned ecu (lotus sc)
-drive belts

Things I've checked:
Fuel pump does start up when putting it into On position.
Checked fuse box in engine compartment and used a fuse tester on each
Checked battery - ~13.5 volts
Checked fuse block in engine compartment - ~13v on both
Reset the inertia switch
Checked ground wire to vvl solenoid
 
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#2 ·
2005?
 
#4 ·
known issue on 05s...

A quick "tap" of the start button and then go to your normal crank to start should resolve the issue...

-Phil
 
#5 ·
It's true! I have recently installed a factory Supercharger on my car and noticed the same issue. A quick tap on the start button then a normal press and the car starts perfectly.

I didn't know it was a known issue, so that's a bit of a relief.

Any idea what causes this behavior?
 
#8 ·
#7 ·
It's not a known quirk of the 2006+ cars (different ECU). It is a known quirk of 2005 cars, SC'd and NA alike, but not ALL NA cars or SC'd cars.

Seems to be at the firmware issue in the ECU.

I haven't spent that much time on it...

-Phil
 
#26 ·
I would think that all emission-controlled, fuel injected cars would have a cold start and cold drive-away strategy built into the ECU. At cold start-up, the ECU would enrich the mixture to account for the denser air. In cold drive-away, the ECU leans out the mixture to aid in warming the engine.

If cracking the TB open a little helps the engine start, then it sounds like the calibration is commanding too much fuel. That's assuming that the idle air control is working perfectly. They tend to get gummed up.

If the engine starts better with the throttle plate opened slightly, then the OP could turn the throttle plate screw slightly to crack the plate open a bit more. In general, you don't want to mess with that screw, but in this case, I think his may be out of adjustment. Lotus, being a small mfr, may have put the ECU calibration through a more limited set of circumstances during test and development. If I did turn the screw on my car, I'd find a way to mark or record the changes I made.
 
#20 ·
My '06 N/A has always been like this, if there are days between starts (always on a minder too). Maybe I should try the throttle trick.

What I've always wondered is why the car is so "cold" on start-up, even in 80° ambient temps. I let it idle for about a minute, then drive off, but it still doesn't run smoothly for a mile or 2. I'm sure it has something to do with the fuel/choke, as I get massive pops and cackles if I let off the throttle in gear (adore it). You'd think it was a new Jag from the sound if it. You'd also think a cold car is normal for the first mile or 2, until you drive a Celica GT-S, which starts and drives from any temp as smooth as silk. Weird that.
 
#28 ·
Perhaps you have a fuel pressure leak? Try hooking a fuel pressure gauge to your fuel rail, start the engine and let it run for a bit and note down the pressure. Turn off the engine and let it sit for an hour or so and check the pressure gauge again. If your fuel pressure fall down by 10psi or more, then you have a leak in the fuel system. It could be a bad injector or injectors, bad fuel pressure regulator, or the check ball in your fuel pump gone bad.
 
This post has been deleted
#30 ·
I have to chime in because this sounds like a similar issue I have, but on a completely different situation.

My car is an '06, stock N/A engine (obviously, like I said, a very different situation). I ordered new spark plugs from a well known vendor. I meant to order NGK BKR6EIX, but was sent NGK BKR7EIX. 6's being for N/A cars, 7's being for supercharged cars. After inquiring, the vendor indicated that the 7's will be perfectly safe to use on my N/A car so I proceeded with the install. They work fine once they are heated up. When they are cold, however, they act exactly as the OP describes. Understood that S/C cars have a lot of other potential complications to cause this problem, and perhaps its just coincidence that my situation and the OP's situation are similar, but thought I'd add my experience to the equation since the spark plugs have not yet been discussed as a potential cause for the OP's car.
 
#32 ·
Would a battery without enough cca cause these symptoms? (I run the Shorai LFX27L3-BS12) Or is my assumption that since it cranks normally, the battery is not the suspect.

Also bought a feeler gauge to measure the gap on the newly installed spark plugs. Will update here to see what I find.

If I can find my old spark plugs (the one with the temp rating for the NA elise), i will install them and see if it makes a difference
 
#33 · (Edited)
I took out my spark plugs, cleaned them with a towel and re-gapped them from .038 to .032. There was a little oil on the threads of the plug. The car started on the first push of the starter button. It sounded weak for a second just as it turned over, but eventually idled normally. Previously, it use to idle very rough for a few seconds (as if it was on the verge of dying), but now it idles smoothly around 1,000, then lowers after a few seconds.

I will try again in 2 days after letting the car sit to make sure it's not a fluke.

Is it possible for the spark plug gap to cause this issue?
 
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