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Discussion Starter #1
Ok guys, you may remember this little issue from before, but I really need some more expert advice on it.
Please offer any advice you can as this has me at the end of my tether. :cry:

The car in question is a 1997 2.0 16v TS 145.

Every 5 or 6k my car gets sick... It starts to hesitate\Kangaroo while I drive. I could be driving at any speed\rpm\gear and suddenly its like the fuel is being cut off and the car stutters like it has no fuel or air.
It doesn't matter if I put the foot to the floor during these "fits" it will still hesitate and will not rev. the revs just die off... then it will suddenly pick up again and VROOOOOOOOOOOOOOOOOOOM....the response and revs are back.
its seriously not nice when your driving in traffic and the car is kangarooing all the time.

I have had the car on the Alfa delaers diagnostic and also a local garages diagnostic machine. Both turned up the same problem in the BOSCH Motronic ECU error log.
"LAMBDA ABOVE UPPER LIMIT".
I replaced the Lambda twice already in the past 12 months. I thought I must have had a faulty one to fail only 6 months after installing it.
However the car started the erratic behavior again about 6,000 miles later. Once again its the same issue according to the diagnostic computer.

So, the question is... why is the lambda burning out every 6k. I know unburnt fuel in the exhaust might damage the lambda, so I have checked the plugs and they look consistent with good fueling etc. not burned\black or damaged.
The car is running very well and is very healthy (157bhp 156ft/lbs). The only mods to the car are a K&N filter and a full supersprint exhaust with decat pipe.
The lambda probe is before the CAT in the 145 so this has nothing to do with it I think.

As you can imagine, Lambda's are not cheap and Im getting fed up buying 2 per year. Is there any was I could feed a false signal to the Lamda plug so that it thinks everything is ok?
Im sure there is a certain voltage it is expecting from the lambda so maybe I can wire up a transistor to just do the lambda job? maybe not... but Im trying to think of any way out of this.
When the car runs right, its a pleasure to drive. fun, quick, nice. but its pure hell with this kangaroo behaviour.
Any (I do mean ANY) advice very greatly appreciated.

Also, does anyone know the very very cheapest place I can get a lambda from? the local dealer is costing me about 170euro!!! (120sterling). Can anyone help me get one cheaper?
I think I'll have to buy one anyways as I cannot afford to be without the car as I need it for work. So short term Im gonna have to bite the bullet and shell out for yet another lambda.

please ask around if you know anyone who may have experienced this specific problem. I can;t be the only one. surely. (I hope)


thanks for reading...

Neil, Dublin
 

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I suggest you get it back on the machine after replacing one. there's obviously something throwing the readings out for the ECU and causing it to overfuel, killing the lambda, or simply run like a bag of nails.

It could be a number of things...water temp, AFM etc.

wrinx
 

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Discussion Starter #3 (Edited)
AFM was changed 2 years back so should be ok. the water temp is an interesting point. my car runs at 60C all the time unless sitting in traffic at which point it might rise to 90 or 95C before fan engages. I've been told that 60C is far too cool and it should run at 80C which is the midway point on the temp gauge? not sure about this. but no other sensors are showing up as failing? Maybe something mechanical is preventing the car from heating up properly. I notice that the hot fan (in car fan blower) is never hot either. only warm. unless the car is in traffic for an hour etc. but normal motorway cruising and it only gets warm. this seems linked to the water temp guage? could this cool running be causing the over fueling and killing the lambda... hmmm.... thats interesting alright wrinx... maybe there somehting in that....
 
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I actually meant water temp sensor...but the effect is more or less the same :lol:

If the car isn't getting hot properly, then yes, it could be overfuelling but many people run cars with nakkered thermo's for months with no problems.

The water temp senser can do all sorts of funny things if it's dodgy but should show up on the diag machine.

wrinx
 

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A few thoughts here. Firstly, lambda probe failure may a symptom, not the cause of the problem. For replacements, try NTK (made by NGK) - better quality & around 60% of the price.

The first thing I'd do is change the thermostat. You should not be seeing big variations in temperature. If the stat's working properly temperature variations should be so small as not to be noticeable on the gauge.

Just thinking about the way the system works, from a cold start it ignores readings from the lambda probe until the temperature gets up to around 70 degrees to allow the engine to run rich until it's warmed up; maybe that's a contributory factor to your problem?
 

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Discussion Starter #6
sound, I ordered an NTK lambda for 64 sterling. (96euro). thats not too bad. The universal one would have cost me 74euro but would require wire cutting etc.
I'm gonna ring local for a thermostat now. I reckin your right about he thermostat being stuck open... I can never get HOT air through the fan heater unless I sit in traffic for an hour. on normal driving Im lucky if I get mildy warm air. This sounds to me like what your saying is right? thanks for the advice.
 

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My wifes old 145 ran 'cold' on the gauge, though maybe not that cold. I suspected thermostat and had the local Alfa workshop confirm the stat was OK. I then met someone wi a 145 who said his gauge showed coolish so I assumed that water temp gauges on 145 read low! Never had any running problems. Ours never showed much variation though, which comforted me that the gauge was the problem not the'stat.
 

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I have owned a few 146's and 145's and the hottest I have ever seen on the gauge is a knats cod over 80ºC. And thats with new thermostats.
 

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Discussion Starter #9
I think this might clear things up.....

Someone suggested that the pipe coming from the thermostat should not get hot after a cold start. This is because the thermostat should remain closed until the car reaches about 70C before opening and allowing the water to flow into the radiator and circulate around to cool it. Using this thermostat is how the car remains a steady temperature.

I think my thermostat is stuck open because the pipe gets hot minutes after a cold start. And I also only ever get warm air from the fan, plus while driving the guage stays at 60C. This doesn't seem right? My GFs punto has hot fan air after about 5 minutes driving. I just don't ever get hot air, maybe warm if Im lucky. Could this because the water is constantly circulating past the heater element cause the thermostat is open all the time. This would explain why it never gets above 60C while driving. Here is a picture I took this morning...

Pciture 1 shows the temperature gauage after 10 minutes of running...

Picture 2 shows the thermostat pipe is already hot even though the thermostat should be closed at about a water temperature so cold.... 50C
 

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Discussion Starter #10 (Edited)
This is the hottest it gets while motorway driving....

But... if stuck in traffic it can reach 95C or 100C before Fan kicks in...

So HUGE variation in temp from 60C (cruising) to 100C (traffic) so doesn't seem likes it the guage, seems like the stat? :eek:
 

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Absolutely, change the 'stat quick. She'll clearly be using a lot of fuel. This could well be a probelm for the lambda sensor. In the old days running rich would have kept the components cool, albeit all coked up. Nowadays the cat probably runs (even) hotter than usual on a rich miture as it tries to burn any excess fuel before it leaves the exhaust system. The sensor is mounted right next to the cat so perhaps it does suffer over time.
 

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Discussion Starter #12
Thanks for your reply Wrenched... Luckily my CAT has long since been replaced,(DECAT pipe) but I think your still right about the extra rich mixture clogging the lambda. One of the primary reasons for Lambdas failing is a rich mixture causing deposits of carbon on the sensor and basically rendering it ineffective. I usually get about 6 months before the lambda fails each time. But I think my car is running rich permanently because its at 60C etc. So Im hoping a new stat might help the lambda survive a bit longer. (and get me some hot air in the car on these cold mornings)
 

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Certainly you can't put up with a non-heater.
Ugh! good luck with a new 'stat'. when we had our 145 and I suspected a duff stat (which wasn't), I took the thing off and was horrified to find it was integral to its housing. Poxy trick! Not like the replaceable sort I'm used too, a stamped thing with a bit of wax in it for 3 quid! My instinct were to replace it regardless. I didn't when I found out the price form AR!
 

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Discussion Starter #14
I changed the Thermostat and Lambda this weekend... Hey Presto my water temperature no longer sits at 60C while on motorway, it sits perfectly midway on the gauge now at 80. I also have hot air from the heater which is nice. So the old thermostat was deffo stuck open the whole time. I'm hoping this new regulated water temp will help keep my mixture more reasonable and hence stop me burning lambdas every few months. I put in a brand new NTK one so I'll see what happens. The car has done a couple of blips in the past couple of days. A BLIP being a momentary kangaroo style hesitation. I wonder if this is because I didn't clear the error memory after I installed the new lambda. Might do that next weekend. Anyway, I have heat, and I have a new lambda, so the future is bright (and warm). :D
Thanks for all the advice... Below is a snap of the dash while cruising on the motorway. Normally I would need to be stuck in traffic for an hour to get the temp gauge to read midway :D lol...

Cheers lads
 

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Hi there! I hope you sort this out. My car had the stat stuck open, it wouldn't even go past the 40° line on the road. In winter the injector light would come on probably due to a too cold engine.

I changed the stat myself (easy job) and now it runs at 80° no matter where I’m at, road or traffic. It has made a HUGE improvement in fuel consumption.

But here’s the catch: my car jerked a little one day, I said mmmm, strange. Then that night I took off for a short 60 mile trip and guess what, a disaster, jerking all the time and complete loss of power. Problem was a faulty fuel pump. I took it to the garage and they changed the pump and also ran a system scan.

Guess what, my lamba probe is not working, it shows a fixed value but the car drives perfectly. Maybe your pump is cutting in & out??? Not a really expensive part to change. Mine was made in Brazil…Maybe the pump relay is acting up??

They are known to fail if you let the tank level get low to about ¼ or lower (how I used to drive my car!!!) not any more, always around ½ a tank.

Good Luck,

Warrior
 

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I changed the Thermostat and Lambda this weekend... Hey Presto my water temperature no longer sits at 60C while on motorway, it sits perfectly midway on the gauge now at 80. I also have hot air from the heater which is nice. So the old thermostat was deffo stuck open the whole time. I'm hoping this new regulated water temp will help keep my mixture more reasonable and hence stop me burning lambdas every few months. I put in a brand new NTK one so I'll see what happens. The car has done a couple of blips in the past couple of days. A BLIP being a momentary kangaroo style hesitation. I wonder if this is because I didn't clear the error memory after I installed the new lambda. Might do that next weekend. Anyway, I have heat, and I have a new lambda, so the future is bright (and warm). :D
Thanks for all the advice... Below is a snap of the dash while cruising on the motorway. Normally I would need to be stuck in traffic for an hour to get the temp gauge to read midway :D lol...

Cheers lads
That photo makes me want to fix my stat now - I get approx 65 degree heat in my engine and when I previously changed the stat it only worked for 3 months! Keep your receipt!
 

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Discussion Starter #17
Hey Guys,

The thing is Warrior, if you were driving for any period of time with the water temp at 40 or 50C degrees then the fueling would have been rich ALL the time, hence its no surprise that a stuck open thermostat often needs to be changed with Lambda and vice versa...

McGuinn buddy, I'll be dropping my thermostat straight back if theres any problems within 12 months. Jim at Barrables in Swords is a pure gentleman so no problems there if I need to change it at all. The most amazing thing is actually having hot air in the car.. Especially appreciated at this time of year.

As for the couple of jerks I had after changing the lambda and the thermostat I did some research. I found out that after any component changes like this I should reset the ECU and clear the errors. My car has been running rich at 60C temperature for a year now... So no doubt it has a few learned fueling habits...

First thing I did was turn on ignition and depress accelerater pedal 5 times within 5 seconds.... I got an error code flash up. (its a sequence of dash flashes using the CODE word on the dash and/or an injector light). I held the pedal in for 10 seconds to clear these errors...

I then disconnected battery for 1 hour. I reconnected and turned ignition on but not engine.(DO NOT TOUCH THE THROTTLE) Left this on for 2 mins... Then turned off for 2 mins... Then started the car and left it to idle for 15 minutes...(AGAIN DO NOT TOUCH THROTTLE) Turned off for 10 minutes.. Then started and went for a drive. This should clear all learned behaviours and now I may actually notice some fuel consumption returns. Even if its only 5% it would be much much appreciated as I do about 300 a week.
I'll see how it goes.. It's driving like a go kart now.. delighted with itself......
 

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Hey Guys,

First thing I did was turn on ignition and depress accelerator pedal 5 times within 5 seconds.... I got an error code flash up. (its a sequence of dash flashes using the CODE word on the dash and/or an injector light). I held the pedal in for 10 seconds to clear these errors...

I then disconnected battery for 1 hour. I reconnected and turned ignition on but not engine.(DO NOT TOUCH THE THROTTLE) Left this on for 2 mins... Then turned off for 2 mins... Then started the car and left it to idle for 15 minutes...(AGAIN DO NOT TOUCH THROTTLE) Turned off for 10 minutes.. Then started and went for a drive. This should clear all learned behaviours and now I may actually notice some fuel consumption returns. Even if its only 5% it would be much much appreciated as I do about 300 a week.
I'll see how it goes.. It's driving like a go kart now.. delighted with itself......

Wow,

I hope I don't have to reset any error codes on my car. That sounds like a bit of a pain in the neck.

Glad to hear the lambda problem is sorted - a cool engine is a definite no-no on modern cars unless specifically modified to run that way.


Keep us posted on how the car runs after ecu reset.

:)
 

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Discussion Starter #19
hey all,

Car is running perfectly. No hiccups at all (touch wood). The temperature stays perfectly steady in the middle of the gauge regardless of town or motorway driving and I have hot air which is just amazing. Having had to wear a winter coat in the car most days its amazing to drive to work in a t-shirt now with the hot air on. LOL. the little things you miss. :D
Fuel economy iseems to beprogressing very nicely although I won't get a good read on this for a week or so. I normally get about 300miles to 50euro (full tank) regardless of how I drive. I'll let you know how it goes though... Hopefully see a few savings...
 

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300 miles doesn't seem too bad.

I also find driving style doesn't really affect the amount of miles I get. If I use a heavy right foot for a full tank, I will get about 300 miles also. If I take it really steady, I get about 320 miles. Hardly worth the expense of having fun :)

After all, that's what they are for otherwise we would all be driving round in 1.9 diesels or Honda Priusis'sises' (or however you spell them)
 
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