3200GT idle and jerky in the first few minutes

[onlinesys]

Morning Gents,

Got the car back from the indie two days ago
After water pump exchange and window regulators
alignment.
The car seems playing on cold start.
Idle rpm sometime at 1300 but back to
Normal after a few minutes. Acceleration
from 1st & 2nd gear seem fine but jerky
at 3rd even though I floored the throttle.
Car seems back to normal after 5-10min

Wanna use the OBDII cable/USB, Bluetooth and
even the wifi one to check the code but no luck.
I used to be able to connect the USB to OBDII and
Fiat 3-pin to retrieve the data but not anymore.

1. Am I connecting to the right plug?
2. What exactly is the idle and jerky reason?

Many thanks

 

[Contigo]

Wrong plug mate, it should be 3 pin like this but with a grey plastic clip not black like the one here....

 

[Contigo]

Looks like:

 

[onlinesys]

Thanks Phil. I did check twice but can't
Find any other 3-pin plug. Well, will try again tomorrow morning
and hopefully could locate it.
The car is perfect when warmed.
Not sure what's wrong with it so definitely need
a OBDII diagnostic.
Happy Easter all

 

[Contigo]

Yes I made same mistake as you. The grey one is usually behind the carpet under the drivers footwell area. Have a good look for it.

 

[timkee330ci]

Since the problem of high idles and jerky only appear when car is cold, would it be due to any sensor that operates the secondary air supply system? that secondary air system only runs when the car is cold.

 

[StuartW]

I had a similar problem with mine and it got the point where it was difficult to start. It turned out to be a troublesome throttle pot but once changed, i've had no further issues

 

[Contigo]

Do a reset. Turn ignition to MAR for 2 minutes and then start car.

 

[onlinesys]

Do a reset. Turn ignition to MAR for 2 minutes and then start car.

Did this twice but no improvement.

Had a morning drive today and it was acting fine but once going to around 3000rpm with the car still nto warming up, the car was jerky and reluctant to rev.
Car performs ok when warmed up but still lacks the 3200-pull-you-back-to-the-seat norm. Couldn't locate the right 3-pin connector neither.

Well, guess it will be back to the indie after the Easter holiday I reckon.

 

[onlinesys]

I had a similar problem with mine and it got the point where it was difficult to start. It turned out to be a troublesome throttle pot but once changed, i've had no further issues

Took the car out again in the afternoon and it went well (since I've driven it in the morning so the car is not reallly cold) but the idle became fluctuating
and car stalled. I also noticed when this happened, the coolant gauge is at the bottom!!! After a few minutes, the car is back to normal with idle at standard 800-900rpm in neutral. (forgot to mention my car is a manual)

What on earth is wrong? Ask another indie to check where is the OBDII port (3-pin) but still no clue!!!

 

[Contigo]

If it stalled then it could be a number of things.

Start with TDC sensor (crank sensor)
Throttle Body.

Did you look for the grey cable? I assume you have the correct 3 pin to OBD cable and also the unidiag software?

 

[onlinesys]

If it stalled then it could be a number of things.

Start with TDC sensor (crank sensor)
Throttle Body.

Did you look for the grey cable? I assume you have the correct 3 pin to OBD cable and also the unidiag software?

Morning Phil,
I really don't know why it happened right after the water pump replacement
I did also put my head beneath the steering wheel
and check but still can't find the grey cable.
Yes, I have 3-pin fiat cable, OBDII to USB cable,
I also have Bluetooth and wifi OBDII adaptor connecting to
IOS apps too.
I am sure I did successfully connect
and even post the DTC codes to this forum
Any chance I could get more info of the exact location from
the workshop manual?

 

[CatmanV2]

I'd be wondering about loose connectors, air leaks and MAF.

C

 

[ledlights]

Hi,

Have a look at the guide for the location of the ECU ISO plug: http://www.sportsmaserati.com/showt...an-early-3200GT?highlight=Reading+error+codes

On my car, stalling was related to the throttle body both before and and after its rebuild (it was incorrectly reassembled when it was converted to contactless) but failing lambdas can also lead to slow response - but it could be a whole range of things. Crank sensors can cause stalling - typically they fail when they warm up and then start to work again when they cool down. Not sure about the MAF - my car doesn't have one.

 

[Contigo]

I'd be wondering about loose connectors, air leaks and MAF.

C

There is no MAF on the 3200 but instead two MAP sensors one downstream and one upstream.

 

[Contigo]

Morning Phil,
I really don't know why it happened right after the water pump replacement
I did also put my head beneath the steering wheel
and check but still can't find the grey cable.
Yes, I have 3-pin fiat cable, OBDII to USB cable,
I also have Bluetooth and wifi OBDII adaptor connecting to
IOS apps too.
I am sure I did successfully connect
and even post the DTC codes to this forum
Any chance I could get more info of the exact location from
the workshop manual?

It is buried beneath the carpet so pull the carpet away and have a good route around. It took me about 2 minutes to find mine tucked away behind a piece of carpet.

I am beginning to wonder now if something has not been fastened up properly. There is a common problem on the 3200 where the plenum chamber plate can come loose, resulting in a high idle speed which is kind of what yours does. This could be a faulty gasket or O ring etc.... Also check the TB gasket as they can sometimes cause problems like this. Until you get it on the OBD codes all of this is just speculation.

I will go and take a pic of the location of mine exactly for you later if you still have problems finding it!!!

 

[onlinesys]

There is no MAF on the 3200 but instead two MAP sensors one downstream and one upstream.

Will MAF cause un-steady idle and jerky acceleration?
The funny thing is that the unusual idle (no matter is high like 1300rpm or unsteady from 500-1500) happened when the coolant gauge is
down to left-most!!!

 

[Contigo]

Normally we could disconnect the MAF to see it run out of loop but you can't do that as there is no MAF.

I would find the cable and get the codes.

 

[Contigo]

From the pic I posted on first page you can see the Pedal Pot and the grey cable is behind the carpet near that. As yours is probably a left hander then it will be reversed. Have a **** good route around behind the carpet and you will find it...

 

[CatmanV2]

Normally we could disconnect the MAF to see it run out of loop but you can't do that as there is no MAF.

I would find the cable and get the codes.

Google fails me. What's a MAP?

C