Hi, I cant reply to your PM because it says:
Migaard has chosen not to receive private messages or may not be allowed to receive private messages. Therefore you may not send your message to him/her.

so i'll post my reply here and hope you get it

cold idle problems on the 1.6 are very common and usually due to a faulty idle speed control valve. the idle actuator moves in and out to let more or less air into the inlet manifold, which adjusts the idle rpm. if the actuator does not move into the correct position the idle rpm will be wrong. the actuator's position is based on the reading from the inlet air temp sensor, which is fitted next to the idle speed control valve. clean them with break fluid or wd40. if in doubt replace them both with scrapyard parts, it wont cost more than a fiver.

the mk1 and mk2 engines have different actuators and temp sensors so only use parts from the same model as your own. you can tell which engine you have by the upper inlet manifold. it will either be metal or plastic.

here's a useful thread - https://www.fiatforum.com/bravo-technical/91627-random-

Hi Jug.

Thanks Mate.

I changed my e-mail yesterday but forgot to activate it, sorry...
I had the ISCV tested OK at a FIAT workshop in december last year.
I will try the air intake temp sensor, do you know what kind of sensor it is, is it possible to test it using a multimeter?
Can a bad Lambda sensor or a bad fuel injector cause these problems?

The only problem is low revs 700-800 at idle, at cold start.
If i don't push the gas pedal during start the engine will stall.
Once the engine is warm, the car drives perfectly, also at idle.
The car never misfires.

You really have cheap spareparts in England.
In Denmark i have to pay around 40£ for the upper intake manifold at a scrappy (they wont sell the air intake sensor alone). :bang:

Anyway Jug, thanks for your reply quick reply

Migaard said:

Can a bad Lambda sensor or a bad fuel injector cause these problems?

Click to expand...

definately not. neither can have anything to do with a cold idle problem.

the only things that make the idle higher when cold are the iscv and the air temp sensor, so if the cold idle is low it can only be due to these 2 things.

you can test the air temp sensor, the attached pic shows a graph so you know what resistance to expect at any given temp. i would test the resistance at a couple of temperatures. for example, i'd expect 10kohms at 0C and 4.5kohms at 20C (approx). a faulty sensor will usually show very little resistance, or an open circuit. if the resistance seems correct, it means the idle speed control valve actuator is not moving as it should. this is basically just a small rod on a motor, so its easy to clean or replace.

Hi Jug.

Thanks, i have a access to a temp test fixture for clima testing electronics at work, i will check it soon, and let you know how it turns out.
It's a simpel NTC, so it can't be very expensive to replace.

Thanks again, you are a great help!

Michael.

Hi Jug.

I have tested the air temp sensor today, all measures were slightly below the
specified values.
At -20C the value is 24K instead of 30K.
At 0C the value is 8K instead of 10K.
At 20C the value is 3K1 instead of 4K5.
I don't know the tolerence of this NTC, it follows the graph but some Kohms below.
This leads the ECU to think the air temp is approx 8C warmer than it really is.
Do you think that this causes the problem?
A sollution could be coupling a 2K2 resistor in series with the sensor.:idea:
I will clean and oil the butterfly valve to be sure that this don't cause the problem.
Is it possible to start the engine with the ISCV closed?
If so, i will start it with the steppermotor un-mounted and look if it really works.

Michael

I have tested the stepper motor by un-mounting it and shut the mounting hole to prevent false air.
When i started the engine the stepper motor moved a bit in both directions and i could feel each step, so it seems to work.
When i was done testing i tried to let the engine idle for a moment, when i put fully load on the electrical side (MAX DEF) the idle speed drops between 450 and 500 RPM, should'nt the engine try to rise the idle speed when the alternator load rises?
I tried to measure the battery voltage during this low idle it was 11,8V.
Do you think it's because of the low RPM's?
When i switch all electrical load off the idle speed rises to 800 RPM and the battery voltage rises to 13,8V.
I really don't know what the next step is to get this car runnig well at idle.
Please let me know if you have any advise.
Michael

it sounds like the idle speed control is working fine. even the air temp sensor is working well enough and should not be the cause of the problem.

the problem you have noticed with the idle dropping under electrical load is almost certainly the problem. you're correct the idle should be increased when under load to maintain an idle of approx 850rpm.

you should have 14.4v at the battery with the engine running and no electrics switched on. since you only have 13.8v it suggests the alternator's output is insufficient.

you should have 13.99v with all electrics switched on. you only have 11.8v. the alternator's output is too low to allow the rpm to be adjusted back to 850rpm. some of this will be due to the low idle rpm (450-500) but it is still a sign that the alternator can not satisfy the demands of the car.

i would definately change the alternator with a scrapyard one, or fit new brushes in your alternator.

Hi Jug.

Hmmm, the alternator is placed behind the engine, not very serviceable...
Ok, I will check the brushes and the voltage regulator on the alternator.
I think i will try to fully charge the battery and couple the battery from my second car in parallel, just to check if the idle problem is caused by insufficent electrical power.

Michael

Migaard said:

I think i will try to fully charge the battery and couple the battery from my second car in parallel, just to check if the idle problem is caused by insufficent electrical power.

Click to expand...

good idea

Hmmmm.
I tried to couple an extra battery to the car so i had 2 fully charged batteries and still the car still idle like scrap...:yuck:
It nearly stalls (below 400 rpm) with max eletrical load.
I did measure the charging voltage again.
14V with minimal load and 13,5V with max load.
So i'll try to overhaul the alternator since the charge voltage is 0,5V to low.
My service manual states that i need to lower the engine to gain access to the alternator (1.6 16V). Is that true, or do anybody have a alternative way to do the job?

Yahoo!!!
Finally the problem is solved.
It was the voltage regulator in the alternator that caused the fault.
A new regulator is fitted and the charging voltage is 14,4V with min electric load and 14,1V with full electric load and it idles perfectly.

Michael

:woot: