Alfa Pages

[Dave(uk)]

since ive had my 33 its always been a bit lumpy; a temporary cure for this has been to remove the 'magic box' as i like to call it... the classic 'relay shaped device' in the sockets for the ecu near the battery. More puzzling is that when the car becomes lumpy again (usually a few weeks after removal) you can put the relay back in and hey presto! it runs brilliantly for a while again.

Its current problem is a new one to me; the 'magic box' treatment appears to have stopped working (i think i used up all the magic!!), now it runs fine, with a high idle (1100rpm) and power application is smooth all the way through the range whilst the engine is cold. As soon as it warms up to normal operating temp (80'C) it idles like a bitch (extremely lumpy and sometimes even tripping itself up and stalling) and power application comes with a hiccup, and sometimes a backfire, unless you rev the engine with the clutch out first.

Just for information my car is a 1990 pre-cat 1.7 16v series 3, with the standard motronic injection system. When it is running well, it runs perfectly, and it is capable of holding a rock solid idle at 800rpm with no trouble, so i am almost entirely sure that my problem is not mechanical.

Someone please help me! im using all my reserves of hope that there is a simple solution to this problem; i want my baby back

thanks, Dave
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'90 Boxer 16v Cloverleaf (Black) (In need of those few last mods to make it perfect, an alfa is never finished )

[Admin]

Hi

There used to be a problem with the 33 which was fixed by a patch lead up to the air flow meter. The excuse for this was that the problem was caused by a buuld up of static. Probably not your cars problem, but you never know

Most likely I would say one of the temp sensors is giving a false reading

All the best

Keith

[Scott Sander]

Hi,

Have you tried investigating if the ECU has any fault codes stored? You can build a simple tester to do this. A "how to" is available on my web site, see the link below in this post.

Although worth clearing any codes in the ECU and see if any are produced now while using the car. The reason is the codes maybe old and lead you up the garden path while triing to work out what is wrong.

Also worth making sure the car is properly serviced, plugs, leads, oil, filters, belts, etc
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Scott Sander
'91 Alfa 33 Boxer 16V Monza - Awesome
http://www.sanderfamily.com

[dd (again)]

It may well be worth cleaning the Thermostatic device
That thing attached to the front of the inlet manifold
above the power steerig pump.
It gets gummed up - clean with injector fluid
The thimble like device inside needs to rotate smoothly
Also check for oil sludge in filler neck and inlet return tract
These may work...

[Matt C]

You mean Idle Speed Actuator

As Keith said, check out your Coolant temp sender unit as this indirectly controls your Idle Speed Actuator (which controls flow of air past your throttle body at idle, Increases idle speed when A/C is engaged and increases idle speed when vehicle is cold, kind of acting like a choke on a carby)
Some Electrical contact cleaner maybe a good thing around any suspect electrical connections, even give your Windscreen wiper motor connector a clean and watch those wipers go like your've never seen before..
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Molto Veloce!

[ak863]

dave,
did you manage to fix the hickups?

i am getting the same problem..
sometimes when the rpm goes from 1000 to 3000 i press the accelator and the car is "coughng" (not from sars). Is it because of fuel distribution?

[Dave(uk)]

my problem seemed to just go away.

sorry, i dont actually know why it went away, but i didnt use the car for a week (holiday ) then i came back and drove to university in it (5 hours at motorway speeds (80-100mph ) and it had no problems, now it behaves perfectly... i just hope the problem doesnt doesnt come back!

one thing i do always have to do when ive left the car for a while and it has been raining is spray WD40 on the distributor and ignition coil, otherwise the spark leaks through the leads and gets to ground. Other than this i did nothing.

Dave
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'90 Boxer 16v Cloverleaf (Black) (In need of those few last mods to make it perfect, an alfa is never finished )

[ak863]

strangely how this coughing somtimes disappears at mine too.
i am starting to think that it could be due to fuel.
suspect i have to take it on a motorway and press it hard.

thanks dave,

Ak