Alfa Romeo Forum banner

Help finding cause of P1320 error

5035 18
Hi, as some of you may know, my car had a lot of problems with the engine lasts months.
The engine is an old 2.4 JTD 10V 136BHP (AR32501).
Finally, most of the problems are gone after new camshaft, tappets, few pulleys, inlet pipe, new GENUINE Bosch maf (Fu** that "compatible" MAF, just made the engine to be laggy, noisier and raise up the fuel consumption) and an oil change (Selenia brand forever, now the engine runs a lot quieter).

However, the P1320 error, which appeared from time to time before, and ended being permanent (all was before I went for repairing) is still there.
The strange is that I never had an engine stop, it just lit the red injector light and ran in low power mode, something like 60 or 70bhp.
And never failed to start!

Before it became permanent, sometimes the error went while driving, it was a sudden explosion of power and turbo's "whoshhhh" and OMG watch the cops! :lol:

I checked the camshaft sensor with a multimeter and it didn't look open. All wires had
resistance between themselves (both in the car's connector and the sensor's).

Anyway, I ordered a new camshaft sensor, it's unexpensive (30 Euro, not genuine but compatible, the genuine parts cost 3 times that!). I'm waiting for it to come.

I read a lot of strange things around this error. Bad battery, crank sensor, cam pulley being broken...
The cam pulley is new, so not possible.
The battery is OK, recently recharged before trying to start the car for first time, because it was stalled for few months. The starter runs fast and the engine starts instantly. Discarded?

Crank sensor. How? I always was able to start the engine, and it never stopped. A bad crank sensor would stop the engine, right?

I'd like to know everything that would cause this error. I want to get rid of all the problems and get my alfa back asap! :thumbs:

Cheers
1 - 19 of 19 Posts

· Registered
Joined
·
716 Posts
Discussion Starter · #3 ·
Thanks. Any experiencies will help. I'm keeping my fingers crossed hoping that changing it will be the end of the problem.
I received the sensor this morning, I told the guy, I'm waiting his answer... he's busy like 18 hours a day :)
 

· Registered
Joined
·
716 Posts
Discussion Starter · #4 ·
He's going to be busy at least all the week.
I made an oscilloscope-like thing to view the sensor signal. It looked perfectly ok.
There is a bit of noise on the signal because I made it quick and fast, the cable is a bit long (1 meter) and can be affected by all the magnetic signals near it, like injectors and alternator.

Camshaft signal view. Alfa 156 jtd 2.4 - YouTube
 

· Registered
Joined
·
979 Posts
Congratulations on your scientific approach. Can your 'scope display two channels? It would be good to see the crank sensor signal as well (or on it's own if needs be), if it's missing the odd pulse the engine might still run since the cam sensor could keep resynchronising the ecu. Are you measuring at the sensor or ecu? The latter is better, to make sure you are seeing what the ecu is. Also check, double check and clean the ecu connector.
If all the above is good you may have to start suspecting the ecu. It may be possible to get plots of the signals via the diagnostic port, but someone else will have to advise on that. In the mean time you could try a long shot: wrap the ecu in a plastic bag and put it in the freezer for a few hours. Refit it quickly and see if the fault disappears until it warms up.
 

· Registered
Joined
·
716 Posts
Discussion Starter · #6 ·
I made few tests. Disconnecting the cam sensor while the engine was running did nothing, everything kept going ok.
However, if I turn off the engine, it won't run again if the cam sensor is disconnected.
It seems to do a full turn with piston firing, and then shuts off the injection, only the starter motor keeps running.
I have an real oscilloscope, but I live in a 5th floor! Also it's almost impossible to park in front of the work, so it'll be hard to get 220v from somewhere.
 

· Registered
Joined
·
979 Posts
I imagine that if the cam sensor signal is lost the ecu can keep the engine running by not loosing count of the crank pulses, so everything stays in sync. (When you try to restart, the synchronisation from the cam sensor isn't there so the ecu doesn't know which injector to open.) Thus if the engine will keep running without the cam sensor connected, the crank signal must be good. Are you sure the fault was there before you disconnected the cam sensor, because both sensors seem to be good at the moment?
 

· Registered
Joined
·
716 Posts
Discussion Starter · #8 ·
As I say, some time ago it was intermitent, appeared and dissapeared while running.
The first time it popped up, I checked the connector and looked a bit loose. I tightened it and it was ok for some time. Then started to randomly appear again , but few days after it became permanent.
When I delete the error it appears again after a second or so.
I'll try to see both signals at the same time to check if the crank and cam are well aligned.
BTW, thanks for the help! :)
 

· Registered
Joined
·
716 Posts
Discussion Starter · #9 ·
I'm sorry for not having resolved this topic before, I hate the threads that ends in a mistery and helps nobody!

The problem was the crankshaft toothed gear, had damage on the woodruff key, allowing some movement. Replaced the gear and the problem was solved.
Auto part Product Rotor Clutch part Machine
 

· Registered
Joined
·
979 Posts
Thanks for getting back to us. We all like a happy ending.
Just for info ref post 6: my 2004 20 valve does start without the cam sensor (I tried it), but takes a couple of revs of cranking. I'm assuming it works out the firing sequence from the uneven compression intervals. I thought that was a pretty neat trick on AR's part.
 

· Registered
Joined
·
716 Posts
Discussion Starter · #13 ·
Well, the car was abandoned for 3 months, because all the workshops denied to inspect it, saying that the engine sound was terminal and had to put a new one, without any doubt.
Then I found a man with balls of steel, took the car looked the car everywhere, said he was going to do it it free time to better inspect and find the problemswhile being cheaper.

He spent a whole month, he said that it was a personal challenge, him vs my alfa. In the end found that gear problem, and also worn out camshaft and tappets.
Price? Apart of the new parts, bought by me, the hand work was equivalent to around 3 hour labour cost on a dealer. :beer:
Sadly I crashed 9 months later...:irked:
 

· Registered
Joined
·
2 Posts
This was the crankshaft one. But the key is part of the gear, you can't just replace it, have to put a new gear.
Hola @DavidAlfa166 tengo un 147 y me funciona bien a pesar de la intermitencia del error de sincronización P1320. Lo que noto es que al salir en primera vibra bastante. En tu caso lo del sonido y la sincronización era por culpa de la chaveta de la polea dentada?
A ver si ese fuese mi caso ya que los sensores no fallan.
 

· Registered
Joined
·
716 Posts
Discussion Starter · #17 ·
El mío empezó con ese error ocasional. Después de unas semanas empezó a sonar a taques (tac-tac-tac), y unos días después el sonido se hizo mucho más fuerte, sonaba a biela.
Y si, era esta polea, que debió aflojarse por falta de apriete, se rompio la llave y se fue desplazando.

English:
Mine started with that ocassional error, few weeks later a tapping noise appeard, and in the following days it became a much louder, like bad rod/big ends.
The pulley probably became lose due insuficient torque, broke the key and started moving.
 

· Registered
Joined
·
2 Posts
El mío empezó con ese error ocasional. Después de unas semanas empezó a sonar a taques (tac-tac-tac), y unos días después el sonido se hizo mucho más fuerte, sonaba a biela.
Y si, era esta polea, que debió aflojarse por falta de apriete, se rompio la llave y se fue desplazando.

English:
Mine started with that ocassional error, few weeks later a tapping noise appeard, and in the following days it became a much louder, like bad rod/big ends.
The pulley probably became lose due insuficient torque, broke the key and started moving.
Gracias por la pronta respuesta @DavidAlfa166 . Hoy he intentado quitar la polea y no hay manera (haciendo palanca con un puntal), osea que por falta de apriete en mi caso no sería. Revisaré también la chaveta de arriba (camshaft).

Saludos
 

· Registered
Joined
·
716 Posts
Discussion Starter · #19 ·
Ojo, que se afloja en dirección al giro del motor es decir, al revés de un tornillo normal.
Va apretado a ~350Nm, necesitarás una barra de un metro y bloquear el volante motor, hay una tapa en la caja de cambios, se quitan dos tornillos y se inserta un útil que agarre los dientes.

English:
Remember the thread is left-handed, it will loosen in the direction of the engine rotation.
It's tightened to ~350Nm, you'll need a ~3ft breaking bar, also locking the crank by removing a cover in the gearbox, 2 bolts out and it'll be out, then insert a tool that holds onto rhe flywheel teeth.
 
1 - 19 of 19 Posts
Top