Just buy a new MAF it seems its tired.

MB

[Edited by Dark Blue Mark - 6/1/2003 11:13:39 AM]

 

Hi

Just fitted my Autometer AFR Gauge this morning, and went for a quick blast, the lights were dancing around whilst on idle, and reading the threads, this is ok, and just a show thing (ie doesnt mean a great deal)

However I noticed that on WOT in 3rd and 4th, it went straight to red as far as the lights go, my car is a MY00, decat centre, AE800 ECU, and K & N Induction Kit

Now im pretty sure the K & N is making the car run leaner, due to more air getting in etc, and im taking it off this afternoon, to put the standard OE filter box back in, so I can compare AFR readings, I also know the AE800 ecu runs leaner than the original AE802 that was in the car

I have a knock link too, and this is static, never more than the first (power) green light, cept sometimes when I start then engine, I get a quick blip of the yellow leds

Is the leaness a cause for concern, or is it pretty much the K & N causing the leaness, I will post back once Ive swapped it back for the OE one

At least I know I can stay backed off the throttle for the time being

Steve

 

I've just put on a Lambda Link, and have the same : red LED on WOT. No Knock shows up on mine either.
Alcazar

 

Same on mine

 

heh

Well Ive just refitted the standard air box, with an ITG Panel Filter in, what I had before I fitted the K & N

Going to go out and thrash it up the dual carriageway, and see what happens, ill try and make a note of boost too

 

Turn the boost up to 2bar and then check it!!:P

It must be seriously running lean to only show red on the autometer mate, after switching my car back to the std injectors but staying on the larger injector map my AFR showed Red..
That was running 35% less fuel


Rob

 

hehe im lucky to be running 1 bar Rob

Right just been out for a blast, 2nd gear 5k rpm WOT RED, then its stays there throughout the gears, no matter the revs

hitting about 13.5 PSI in 3rd, 4th @ peaking at 15PSI in 5th

car is now standard, cept the decat centre @ backbox (magnex)

took the dawes off a few weeks ago (set to 16PSI) and took the K & N off today

Knocklink still quiet too

One thing tho, as I had to tap into the ECU wire, I disconnected it all & the battery, so effectively its had an ecu reset, and ive only done about 6 or 7 miles tops

Hopefully it will calm itself down, once its learnt

Steve


[Edited by *Sonic* - 5/24/2003 7:01:27 PM]

 

Check your voltage from the lambda mate.
got a multimeter??

Rob

 

yep, got one somewhere A Beckman Industrial Digital one

what voltage should I be getting at the sensor ?

 

not sure if this is right or not

on tickover its reading between -22.8 mV and drops to about -19.5 mV then backup to about -21 mV

cant drive it with the meter connected, as the probes wont stay in place



[Edited by *Sonic* - 5/24/2003 7:36:30 PM]

 

Air Fuel Ratio - Lambda sensor

MV CO 2 AFR
lean 700
lean 720 1,0% 14,0 : 1
lean 740
lean 760 2,0%
lean 780
lean 800 3,0%
lean 820 4,0%
ok 830 4,5% 0,2 - 0,6
ok 840 5,0% 13,0 : 1
good 850 5,5% 12,5 : 1 0,6 - 1,0
good 860 6,0% 12,0 : 1
good 870 7,0% 11,5 : 1 > 1,0
rich 880 8,0% 11,0 : 1
rich 900 10,0%

 

Thanks Johhny

I take it those are voltages ?

Ive just rewired the earth connection, and ran a big earth cable from the battery to the ECU casing bolt, and fitting the AFR Earth to this point, and took some readings

On tickover it is sitting around .750 volts

just took it out for a quick blast again, and in 2nd WOT big red lean light, then same into 3rd gear, then the gauge goes off, till I let the engine idle again, then its disco lights

although just then whilst idling, the lean light was flickering on and off

dont know if this makes any difference but below is the results of my emmissions test on the MOT last week

CO Level @ 2746rpm = 0.15%
HC Level @ 2746rpm = 13 ppm
Lambda @ 2746 rpm = 1.00

CO Level @ 779 rpm = 0.05%




[Edited by *Sonic* - 5/24/2003 8:10:26 PM]

 

They are milli-volt signals. Is there a way you could connect your multimeter to the signal point where it enters the ecu and try and read it when WOT or better still get a passenger to read it and take notes. Where are you picking up the signal for the lambdalink? perhaps you could connect your meter here to monitor?


[Edited by Delboy2 - 5/24/2003 9:57:00 PM]

 

Thanks Delboy

I had the meter connected to the ECU pin, I have the AFR attached to, and to the same earth

youre right I do need a passenger to read & make note of the readings when on WOT, I'll have to see if I can hook up my other multimeter (much longer cables on them) so it may be possible to take some WOT readings

Steve

 

If it really is running as lean as that Sonic, it is of concern. You may not get knock indications but the pistons could still be running very hot and getting close to burning.

Hope it turns out ok.

Les

 

Right

been out for another spin, and basically the gauge is showing green (rich) for the 2nd gear and starts to go to the red after about 5.5k revs

in 3rd & 4th & 5th on mild acceleration it stays rich until I hit just over 4k rpm, then it rapidly goes to the last red led (lean as f*ck) and then off the scale (this according to Autometer is when the car is so lean (ie no voltage) it cannot register

the gauges reads from 0.50V to 1.00V

with 0.750v as being the start of the rich leds

If my car is really running that lean, wouldnt it have gone bang by now? still absolutly no knock, car is as smooth as anything through the rev range upto 7krpm

I do mostly trundle along tho (due to work traffic) but on the runs to Santa Pod, its basically maxing it through the gears for most of the journey (a very good country road trip) surely this much engine load & indicative leaness, my engine would have gone bang

Or is it that the gauge only reads 0.5 to 1.0 volts

Steve

 

you could have a faulty lambda sensor!

 

Far more likely to be a knackering lambda sensor than anything else. The first sign is a fatigue with temperature. A good sensor might stay on the top light on a standard car for a whole track session when on WOT, but a failing one can go off after just one blat through one gear.

 

Hmmmmm!Mine is doing almost exactly the same, but Bob and Branko will advise when I go there on 5th July.
Until then I'll take it a bit steady, just in case.
Alcazar

 

Just seen the price of Lambdas from a dealer, any way of double checking to be sure ? or is it a select monitor job

Could possibly explain why yesterday I was struggling to keep up with Ayde who has an identical car to me, and idenctical zorst

Thanks for all the replies upto now too


[Edited by *Sonic* - 5/25/2003 7:39:58 PM]

 

Does the heat at WOT and high rpm cause the std sensor to read lean??

 

Sonic, I've just fitted a Dawes device and the AFR was showing the car running lean. I have today removed my K&N induction kit and replaced it with the standard air box and K&N panel. Everything is OK now. I get the occasional red light but nowhere near as much as with the induction kit.

 

Have you taken the live and earth feed straight from the battery..???

Your knocklink is probably not showing anything at WOT because the ECU doesnt use the lambda sensor to control fuel at this point (WOT)...??

But you dont want it to be running lean when cruising.

Dan

 

Dan

Originally I took the earth from the ecu, but the voltage readings where stupid, so I fitted an earth strap from the ecu bolt, and fed it to the main block under the intercooler, which in turn goes straight to the battery my earth strap wasnt long enough, then I starting getting sensible readings

The positive is tapped into the cigarette lighter live (no other use for it )

when cruising it is all over the place, discos'r'us as you would expect, on mild throttle it goes straight to rich, and stays there till it gets over 4 k revs, then a rapid drop to lean, until the gauge goes off completly, like when deccelerating

back below 4k it comes back up to rich, 1st & 2nd gear are ok upto 5.5k, then it goes right to lean and off

After Johnny Gav, and John Banks mentioning the lambda sensor, and checking up on some older threads, I could possibly have a faulty lamdba sensor

I took the K & N Ind Kit off yesterday, and the Dawes has been off for a few weeks, so the car is virtually standard cept a magnex backbox & res centre

knock is quiet as a mouse, bar the odd led blip when I first turn the engine over (so I know the knock sensor is ok)

the car has done 25k miles, and is 3 years old next week, engine is fairly smooth (ie seems to run & sound fine) although it doesnt quite seem as quick as it should be on WOT

Steve

 

The lambda is virtually a 30000 mile 3 year consumable.

 

LOL, I didnt know that, thanks John

looks like im getting a new one then, possibly the Halfords one, as its half the price

 

Sorry to jump on the bandwagon, but I think I am having similar problems...I fitted my AFR and watched the voltages creep ever downwards. Now I just can't get a reading at all.

But weirdly, the car seems to run & idle fine, though it does smell very "petrolly". Could this be a knackered Lambda sensor too?

 

Group buy on Lambda sensors anyone ?

Ive been reading up on some lambda threads, including some re MOT & emissions tests, poor performance, sooty exhausts, erratic idle etc

I did notice today whilst cleaning the car, that there was a bit of soot around the exhaust, never noticed it before when cleaning, but today it seem to stand out, only a little was there, but enough to notice it

when I first got the car, it idled around 1k until warm, then it dropped to about 750rpm, but the last few months it idles at 1500 until warm, then down to 750rpm

Im going to double check the voltages again tomorrow, if I can find my battery for my big mulitmeter

 

There was a way I checked a lambda sensor in my old MR2 turbo when I thought there was a problem. Only thing is with the Scoobie is they have a heater in the probe(3-wire). Well anyway with your meter you had to connect the +ve to the Lambda signal, -ve to the body/ground, set to milli-volts then heat the probe with a propane torch. The milli-volt signal should reach 600mv within 15-20secs and should be at 900mv within two mins and should'nt drop(heat soaked/looking for breakdown). When the heat is removed the mv signal should drop rapidly! By the way the one I checked was fecked! This might work?

 

Oh yeah forgot to say, the meter you use should be a high impedance type (Digital preferably)