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Old 01-21-2013, 01:20 PM   #1 (permalink)
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Engine Stall Power Loss Solved!

Hi,,

I thought I needed to write this with the easiest search criteria for whomever should have the same issue I did.

I have a KoldFire tune and recently my Exige started stalling and losing power until the problem really became a major issue that totally freezed the car. Moreover, the AFR started increasing and became up to 14-15 on WOT at high rpm, with the car totally losing power.

Having scanned the engine, the MAF value was 2.85 on idle whereas all other values of Injector trims were normal. THe O2 sensor readings were oscillating up and down which was normal as well.

I replaced the MAF and the car didnt react on the first drive. However, on the second drive, it started to pick up. After running a whole day, it became much more responsive in terms of power and the stalls reduced drastically.

On the third day today, the car has self-learned and is surging more power than I have ever felt before! The stalling: still about 10% of the time but I can live with it.

THe MAF value on idle is now 3.2, a slight increase from the defective old MAF which proved to have made quite a difference!

Cheers,

Wael
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Old 01-21-2013, 07:24 PM   #2 (permalink)
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glad you found it. I have a similar issue, but not suspecting the MAF.
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Old 01-22-2013, 05:10 PM   #3 (permalink)
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Thanks for the info. Just hooked mine up to a live reader and i'm seeing values of 2.71-2.75 g/s for my MAF. I am having stalling issues just leaving it out to idle. I think i'm going to pick up a new MAF sensor.
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Old 01-22-2013, 09:29 PM   #4 (permalink)
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you're reading these MAF values at idle? what is it @ WOT?

I'll have to hook up my reader and check it out.
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Old 01-23-2013, 02:06 PM   #5 (permalink)
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Quote:
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you're reading these MAF values at idle? what is it @ WOT?

I'll have to hook up my reader and check it out.
The values were at idle. I didn't get a chance to read the WOT values. Haven't really noticed a powerloss I thought I was just getting used to it. Still need to get it dyno'd and compared to my stock base line.
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Old 02-10-2013, 09:32 PM   #6 (permalink)
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ok, mine is reading .5 lbs/min @ idle

.8 lbs/min on decel

what is conversion from g/s. aarrrghgh [.5*(453.6/60)]

SO mine is reading 3.78 g/s?

sounds like my MAF is fine then.
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Old 02-11-2013, 07:07 AM   #7 (permalink)
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Which/what readers are you ppl using?
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Old 02-11-2013, 10:31 PM   #8 (permalink)
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i'm using innova 3220, iirc
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** save ~10 lbs gain 1 hp ** EQ: Y=(190*X) / (1984-X) where Y is (HP) and X is (lbs)

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Old 02-17-2013, 02:56 PM   #9 (permalink)
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I replaced my MAF with a new unit. So far it hasn't stalled It has only stumbled once or twice below 500 rpm's but the car managed to save itself. The car is so much more enjoyable now not having it save it from stalling at every other light. With the old MAF sensor it was stalling at least once every drive. Thanks for the tip Waz!

P.S The car has cold started a little rough the first few times. I'm wondering if the ECU is relearning.
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Old 02-17-2013, 10:27 PM   #10 (permalink)
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glad you solved the problem Roger. Car feel more powerful, too?
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Old 02-18-2013, 10:59 AM   #11 (permalink)
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glad you solved the problem Roger. Car feel more powerful, too?
Not sure if it's just all in my head but it seems to pull quite a bit harder after 5k.
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Old 02-25-2013, 11:17 PM   #12 (permalink)
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Weird... I borrowed a good friend's fancy scantool that reads live data and at idle it was reading even lower than my previous MAF sensor. It was fluctuating between 2.1-2.2 g/s
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Old 05-10-2013, 11:05 AM   #13 (permalink)
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Hi,,

As a follow up to my post here, I was shocked to have the idle-stall again!
The power was not lost this time and the MAF is all brand new!!

I decided to give the car to the garage for a full strip of vacuum lines and intake/exhaust installs.

To our surprise, the header had a large crack (2Bular is NOT to blame here: the install by the previous garage was bad, very bad!!! No need to elaborate...). The mechanic reviewed vacuum lines and restored and retight all the surrounding parts.

All fixed and done, SURPRISE!!: the car is as smooth as out of the factory! The rpm drops to 1.3k then slowly to 1k and settles under. The idle-stall which was unbearable is once again solved.

As much as we thought it was the KoldFire tune, then again Lukas proved he was again so right by continuously asking me to review the leaks! For months he asked me to do that and I neglected the possibility of such a mechanical fault.

I hope many of the members here read this as to really go deep-in mechanically when they experience the idle-stall syndrome!

Thanks,

Wael
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Old 05-10-2013, 07:31 PM   #14 (permalink)
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Glad you regained your trust in the car. Seems weird you could screw up a header install, its pretty straight forward on this car
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Old 05-10-2013, 08:47 PM   #15 (permalink)
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I had the same problem. Turned out to be my crankcase vent lines were connected backwards. Same exact symptoms.
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Old 05-10-2013, 11:40 PM   #16 (permalink)
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Quote:
Originally Posted by wazexige View Post

To our surprise, the header had a large crack (2Bular is NOT to blame here: the install by the previous garage was bad, very bad!!! No need to elaborate...). The mechanic reviewed vacuum lines and restored and retight all the surrounding parts.
where was the crack in the header?
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WTC 2
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Old 06-16-2013, 11:24 AM   #17 (permalink)
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The guy who fixed the header is a rookie.. To say the least!
I dont know where the crack was, it was repaired in my abscence..

Wael
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Old 06-16-2013, 11:53 AM   #18 (permalink)
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Quote:
Originally Posted by Stale_Hotdog View Post
I replaced my MAF with a new unit. So far it hasn't stalled It has only stumbled once or twice below 500 rpm's but the car managed to save itself. The car is so much more enjoyable now not having it save it from stalling at every other light. With the old MAF sensor it was stalling at least once every drive. Thanks for the tip Waz!

P.S The car has cold started a little rough the first few times. I'm wondering if the ECU is relearning.
What supercharger do you have?
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Old 06-18-2013, 09:14 PM   #19 (permalink)
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What supercharger do you have?
This is on the oem exige s mp62
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