sorting VHPD drivability issues

Topics relating to the series 1 Exige
tlracer
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Re: sorting VHPD drivability issues

Post by tlracer » Thu May 02, 2019 5:30 am

Glad you got it sorted and amazed you were able to get a 2Bular system...

...when I ordered one I put up with months of missed completion dates, excuses and finally told that S1 systems were no longer available ( indeed they only returned to the catalogue recently ).

Anyway well done and enjoy the car!

winthattt
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Re: sorting VHPD drivability issues

Post by winthattt » Thu May 02, 2019 6:40 am

That’s great news. As I added on my Exiges day post.....my vhpd went mad popping, banging and very rich just before the Anglesey Exiges day. I fitted some new Ht leads and it has never run sweeter. It’s always been good (after I replaced the lambda sensor) but now pulls 30mph in 5th.

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Re: sorting VHPD drivability issues

Post by Evoman » Thu May 02, 2019 9:30 am

Excellent chaps, they are sweet when running properly 8-)

Pottering along with no hesitation just blip through the gears effortlessly, like a different car it is and the mid range pull up to 5k is almost disturbing. But on my test drive I noticed a strong fuel smell when pulling up at a junction. Not the running rich smell but neat fuel smell - I suspect the fuel cap seal as when I released it there was some petrol sitting in the top of the filler recess and it didn't seem to hiss with pressure release when I took it off. Replacement seal if I can find what size is needed next! Perhaps also the fuel breather hoses but cap seal first I think

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Re: sorting VHPD drivability issues

Post by trackrod » Sat May 04, 2019 8:04 pm

Good news that you finally found the reason for the rich running, thanks for sharing :thumbup:
What do you think, how did the exhaust leak messed up the mixture? Could be that the missing back pressure had an influence on the MAP values or maybe some air has been sucked in to the exhaust system and corrupted the lambda readings.

Has the fixed leak had any influence on the idle MAP readings?

Keith, what brand of HT leads did you use?

The Exige is able to run properly with the original ECU. But the MAP based load calculation principle is very, very sensibel to all sorts of faults.
I had the opportunity to swap cars with a fellow German Exige S1 owner whose car had been switched to an Emerald system. He was surprised by the smooth running engine on my car and said he would have never switched to an Emerald if his own car had been running like mine.
The most noticeable thing for me on his car was the better mid range torque.

I still got those small hesitations below 3000 rpm but maybe I'm just to sensitive.

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Re: sorting VHPD drivability issues

Post by winthattt » Sun May 05, 2019 9:08 am

Klaus,

Magnecor red leads from Geary. Mine must have been faulty for a while as it really is better than ever. Since then I have also disconnected the catch can and refitted tge re-circulation of breather gasses, the catch can never caught much, just water from cold starts. Car is much less smelly now, I’ll refit for track days.

Keith

Evoman
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Re: sorting VHPD drivability issues

Post by Evoman » Mon May 06, 2019 9:23 am

trackrod wrote:
Sat May 04, 2019 8:04 pm
Good news that you finally found the reason for the rich running, thanks for sharing :thumbup:
What do you think, how did the exhaust leak messed up the mixture? Could be that the missing back pressure had an influence on the MAP values or maybe some air has been sucked in to the exhaust system and corrupted the lambda readings.

Has the fixed leak had any influence on the idle MAP readings?

Keith, what brand of HT leads did you use?

The Exige is able to run properly with the original ECU. But the MAP based load calculation principle is very, very sensibel to all sorts of faults.
I had the opportunity to swap cars with a fellow German Exige S1 owner whose car had been switched to an Emerald system. He was surprised by the smooth running engine on my car and said he would have never switched to an Emerald if his own car had been running like mine.
The most noticeable thing for me on his car was the better mid range torque.

I still got those small hesitations below 3000 rpm but maybe I'm just to sensitive.
I must plug in the OBD reader again and take a look at readings for MAP and fuel trim, will be interesting to see. I will try to post up a photo of the removed exhaust system, but yes back pressure must have been so low with all the baffling burnt out of the OE system AND two big holes! Perhaps the flexi section leaking which is right next to the lambda had a larger impact on the mixture.

I would always step out of my car with that 'Exige' odour, my jumper would retain that motorsport race day smell, now, none, just doesn't smell at all.

My car also feels like there is a fatter torque curve in the delivery, it was starting to feel like a 2 stroke, all top end and little in the middle. Now really quite civilised too with pottering possible though there is still the occasional though not often hesitation when going real slow in town say in 4th at 30mph.
Attachments
Exige old exhaust.jpg

winthattt
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Re: sorting VHPD drivability issues

Post by winthattt » Mon May 06, 2019 12:30 pm

If that’s the OEM exhaust it is amazingly heavy. I had a new spare which I chucked in the skip.

Evoman
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Re: sorting VHPD drivability issues

Post by Evoman » Mon May 06, 2019 3:25 pm

winthattt wrote:
Mon May 06, 2019 12:30 pm
If that’s the OEM exhaust it is amazingly heavy. I had a new spare which I chucked in the skip.
Yep that was the OEM bit of kit, 2Bular on the car now which I like a lot although I do slightly miss that hornet's nest zing that the old system had however I now have a lovely burble sound.

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Re: sorting VHPD drivability issues

Post by Evoman » Tue May 07, 2019 3:56 pm

Another update for info purposes, as trackrod suspected my MAP reading now has also similarly dropped from around 68-69KPa to 61-62kPa.

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Re: sorting VHPD drivability issues

Post by trackrod » Fri May 10, 2019 8:44 pm

Good to hear that the idle MAP value finally dropped to a similar value like on my Exige after the fix. So it looks like that checking the idle MAP value gives a valuable first indication if there is something wrong in the induction/exhaust system.

I think it was 'thommo' who reported that when he fitted a decat pipe to his S1 (which runs the original ECU) the drivability got worse. Looks like that the exhaust back pressure has got some influence on the MAP readings.

Klaus

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