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Guest · Posted: Thu Jun 02, 2005 12:48 pm Post subject: Lumpy 33 16v

I'm urgently looking for help..
I'm on to my 4th alfa romeo 33, I currently own a 1993 1.7 16v.
When the engine is cold or has been stood for a day or so, it doesn't run right untill it warms up. the engine feels hesitent untill you rev the engine above 3,000 rpm however i'm not to keen on this because you shouldn't rev a cold engine.
It's had a full service with bosch platinum sparks plugs, castrol gtx magnatec fully shync oil and a lamba sensor and the cam belts changed but nothing has cured this.

I've been told that 16v are abit lumpy untill there warm but this is just impossible to drive.
All my other 33's have been 1.7 ie and i've never had much trouble with them apart from a wire loom fire. Please any advice would be much help
Thank you

Laki · Alfasud Joined: 06 Sep 2004 Posts: 74 Location: Ljubjana

Had a 1.7ie 8V and had some problems like thisas weel...Had to change Motornic computer to solve problem....If you can try by replacing it before you buy its good option
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-- ALFA ROMEO 33 Q4 --

paddy granger · Alfa Sprint Joined: 12 Aug 2003 Posts: 248

Could it be the HT leads? Confused

Would the effects of dried out HT leads be more observable with a cold engine?

tvatavuk · Posted: Fri Jun 03, 2005 8:08 am Post subject:

Don't know anything about BOSCH platinum sparks, which model are you using?
AFAIK Castrol gtx magnatec isn't fully synth, only RS Formula is fully synth oil.
Did you try replacing distirbutor arm or cap?
Have you replaced air filter, fuel filter. What is current millage, when was last time you ultrasonicly cleaned injectors?

Why did you replace lambda probe? When you replaced it did you disconnected battery for half of hour or more, allowing Motronic unit to reset?
What is state od catlytic convertor can you hear rattling?

When you rev your engine, and release pedal does fall of rpm slow up around 2000-2200rpm with bit more engine shaking then falls normaly to idle?
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Tino Vatavuk
Little black dress which replaced Alfa Romeo 33 S 16v Permanent 4 GMo

john 33_16v · Posted: Fri Jun 03, 2005 9:35 am Post subject:

Hi,

As Tino has said, try disconnecting the battery.

You could then try a fault code test, to see if you get possibly a lambda fault, such as 'lambda probe reaches min or max of range'.

Was it ok before the lambda change? Was the lambda a bosch item?

My '93 16v had a similar problem, plus an intermitant flatspot, after fitting a rogue Lemark (halfords) lambda. I then fitted a bosch lambda (aprox £60 from decent parts factor), and it sorted it all out.

John

tvatavuk · Posted: Fri Jun 03, 2005 12:35 pm Post subject:

Also right after you connect battery it ECU is empty you need some millage (100-200km) with different rpm for ECU to learn new settings.
Funny thing is that until it learns it can have iregular idle & accel.
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Tino Vatavuk
Little black dress which replaced Alfa Romeo 33 S 16v Permanent 4 GMo

Guest · Posted: Sat Jun 04, 2005 7:26 pm Post subject: lumpy 33 16v

Thanks for all your replies. I had a bosch lamba probe fitted 2.000 miles ago the car has only done 57,000 i had the full service done at 55,000 all the filters were replaced oil, air , fuel. and spark plugs and a cam belt change.

The car has had this flat spot since i brought it. Checked the ignition timing and replaced the distributor arm and cap.
Timing is currently at 2 degres b.t.d.c. In the haynes manual it showed that the timing can not be altered by movement of the dizzy. it was all e.c.u controlled.

Have been informed that a new air map sensor or air flow meter may be required or a new e.c.u.

However when i fitted the new lamba probe i didn't disconnect the battery, should i try doing this and see if the e.c.u will reset?

Thank you all again for your help

tvatavuk · Posted: Mon Jun 06, 2005 9:09 am Post subject:

Yes, If replaced lambda probe was defective, I think it would be wise to disconnect it for an hour or so.
In case you have you have alarm or engine start disabler, coded radio unit you should read their manual, to see if you have all what it takes to enable them after power loss.
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Tino Vatavuk
Little black dress which replaced Alfa Romeo 33 S 16v Permanent 4 GMo

Guest · Posted: Thu Jun 09, 2005 2:55 pm Post subject:

thanks for your reply tino

Was just reading in another problem page about lamba sensor readings not checked mine as yet but, someone replied taht 33 16v switch off there lamba readings after 3-3.5k rpm this is when mine clears up as well.

HMMM very puzzling.
Think my lamba probe could be a faulty one from the shop?
Will check what it is reading tonight and let you know
Thank you again you have been a big help