Lambda sensor

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kerryxeg
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Re: Lambda sensor

Post by kerryxeg » Wed Aug 17, 2016 5:06 pm

If it was a factory fit 190, I believe they changed the timing gears to provide the 190 correction. I guess that could mean the timing may or may not be perfect, but I've seen previous comments from people who switch from std 190 to verniers which suggested the std setup was spot on.

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Evoman
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Re: Lambda sensor

Post by Evoman » Fri Aug 19, 2016 5:40 pm

Hey folks

I had an awesome drive in the Exige to Derby, the car ran great then this morning the kangarooring and stuttering is back :(

There's a distinct smell of fuel when this happens which would suggest it is massively over fuelling. Any bright ideas people?

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Dominic
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Re: Lambda sensor

Post by Dominic » Fri Aug 19, 2016 9:09 pm

It could be unrelated to previous issues. Mine ran very rich when it had an air leak in the inlet manifold gasket.
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Ferg
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Re: Lambda sensor

Post by Ferg » Fri Aug 19, 2016 9:17 pm

Buy the ECU. It's the only one I've seen for sale in recent times, they're quite rare, and it will prove whether your ECU is at fault or not.

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kerryxeg
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Re: Lambda sensor

Post by kerryxeg » Sat Aug 20, 2016 12:17 am

Dom makes a good point if its intermittent then maybe unrelated to the previous issue. A couple of issues I've had on similar theme over the years

Check the vacuum hoses very carefully, they perish and crack.
Worth trying a different set of HT leads if you think the ignition isn't quite right, I recall ignition on the VHPD is quite sensitive to lead performance.
Crank speed sensor? Search exiges.com, but I think someone had an issue with it which screwed up the ECU.

You are more than welcome to try my ECU, but being the 177 it's a little different to the 190. Actual power was over 190 when it was tested with my car years back so I think the rating was a bit misleading or maybe I was just lucky with my engine.

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Ferg
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Re: Lambda sensor

Post by Ferg » Sat Aug 20, 2016 4:35 pm

From speaking to you before I think you've replaced most of the ignition system already, but if you need to borrow anything off my car let me know. :thumbsup

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Evoman
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Re: Lambda sensor

Post by Evoman » Mon Aug 22, 2016 9:45 am

It's not intermittent, it very consistently happens I have now pinpointed as soon as the coolant temperature hits 66 degrees the stutter and kangaroo starts. Up to that temperature it runs sweet though still smelly of petrol again.

With the new lambda fitted which lasted 250 miles it ran sweet from cold right through to normal operating temperature and there was no petrol smell.

So why did it run fine with a new lambda and why has it apparently not lasted very long at all? ECU swap time perhaps.

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Shug
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Re: Lambda sensor

Post by Shug » Mon Aug 22, 2016 10:15 am

66 degrees indicated probably coincides with the cold running enrichment trim completely clicking off (it'll be a curve applied to the fuel map) The weird thing here is the lambda sensor fixing it for a while then going phut.

Two things to test, IMO, first - that the replacement lambda is borked. You should be able to get voltage from it that makes sense when the engine is running (assuming you can get a probe on the wires with it in situ - can't remember where it sits on the Exige manifold). Perhaps there's a wiring issue there that moving the wires around to replace temporarily fixed, but they've settled back and it's returned to a failure state. Second, if you can get a wideband sensor on the car - even a loaner as a test - to see just how rich or lean it is. And especially to figure out what it's doing around the period the stutters start. Logging would be great.

If you can swap out an ECU, it could just work. I'd want to know what the existing ECU was doing though, just for peace of mind to know that it's fixed. I get a gut feeling that it might be around the phase that closed loop is handing over to open loop and there's a glitch at that point in the map on your specific combo of engine, ECU and cam timing. Doesn't explain a new lambda actually fixing it for a while though. Without seeing what the ECU is doing, it's guesswork though.
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Evoman
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Re: Lambda sensor

Post by Evoman » Tue Aug 23, 2016 12:43 pm

Shug I get what you're saying, thing is I ran the car for a year with no hesitation or stuttering issues at all.

It started after picking it up from a garage that did work to sort a running rich issue which was picked up at MOT. I think the running rich issue developed a few months before the MOT as it became noticeably smelly from start up. It wasn't smelly in the first half year of ownership at least and returned 40mpg+ on the long run when I drove it from Essex to Scotland. No stuttering at all though right through from cold to running normal temperatures.

When I collected it from the garage that did some work to resolve the running rich issue and this included replacement of fuel rail and injectors, spark plugs, a few vacuum hoses and they retapped the thread for the lambda sensor when they replaced that. On collection the car idled at 2500rpm and didn't settle. So I returned having driven less than a mile. Garage took a look and went for a short test drive, high idle was there and then it started kangarooing and stuttering - they reckoned it had run out of fuel. A gallon was put in but ever since then the kangarooing has not gone away apart from when disconnecting the lambda and then with a new lambda.

So was the kangarooing from running out of fuel entirely unrelated to the kangarooing it still does?

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Shug
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Re: Lambda sensor

Post by Shug » Tue Aug 23, 2016 1:50 pm

Sorry Rich, wasn't aware it was an issue that had developed and the car had previously run perfectly - original query was just related to your replacement of the sensor. We're kinda chasing symptoms here.

I'll have to call stumped now. Kangarooing being affected by disconnecting and reconnecting a Lambda can only be related to it going from closed to open loop AFAIK - but how that fault state has developed? Dunno. If it did run out of fuel, has the filter been replaced in case it's full of crap from the bottom of the tank? That's grasping at straws though. Wouldn't relate to the original issue of it starting to run rich and the resolution work for that not working.

It's a catch-all thing to look at the ECU, but at the end of the day, it does control everything and if it's seeing the right values and there's no external issues introducing changes (vacuum hoses, dodgy injectors etc) then my call would be to look at trying another ECU if you can source a loan - Kerry's 177 would be a start, but as it's not the same map, might just fix it while the underlying issue is still there - worth a try though as at least if it still has issues on a different ECU, you can definitely rule out ECU issues.
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Evoman
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Re: Lambda sensor

Post by Evoman » Tue Aug 23, 2016 4:50 pm

Cheers Shug, that logic makes sense. You know I am still inclined to swap out the spark plugs for the original iridium plugs that it ran before. Perhaps the ECU is happy to run for a while on a different heat range plug then starts to develop running issues if its not the ideal heat range for that map. I wonder if the 190 map was developed to run a specific set of plugs? Not sure if that was part of the 178 to 190 conversion. It's just a hunch kinda thing but given it did run great before.

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kerryxeg
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Re: Lambda sensor

Post by kerryxeg » Tue Aug 23, 2016 6:15 pm

This sounds very similar to your problem:

http://www.exiges.com/bb/viewtopic.php? ... it=190+177

So more things to consider: coil pack, coil pack fuse and fuel pump.

Do you know for certain which ECU you have? The 190 ECU's have 190 written on them in marker pen. It may be completely irrelevant anyway.

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Evoman
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Re: Lambda sensor

Post by Evoman » Tue Aug 23, 2016 8:27 pm

kerryxeg wrote:This sounds very similar to your problem:

http://www.exiges.com/bb/viewtopic.php? ... it=190+177

So more things to consider: coil pack, coil pack fuse and fuel pump.

Do you know for certain which ECU you have? The 190 ECU's have 190 written on them in marker pen. It may be completely irrelevant anyway.
It does sound similar though my car is not cutting out at all just the kanagoorey bit is the same though.

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Evoman
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Re: Lambda sensor

Post by Evoman » Thu Jun 01, 2017 7:22 pm

I thought I'd post an update on this so the thread is complete as when searching through these kind of threads it's frustrating when the conclusion isn't posted - could be helpful for other folks experiencing similar issues in the future.

So the long and the short of it was very simple and rather frustrating I must say. The lambda sensor that was replaced was not the the same as the OEM item. I decided to replace it after having the car checked out by an independent professional as they said buy a new OEM item and run it. On changing out the lambda it was clear that it looked completely different to the OEM item.

Result, the car runs spot on, zero stuttering and running brilliantly especially so after this, new iridium plugs and a new TPS. Very sweet idle, very responsive and torquey feeling low to mid range and very impressive.

:D

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