2003 Alfa 156 JTS Fault codes P0120,P1121,P1122, P1682,P1687 & P1688 The engine has an idle speed of 1250/1600 rpm will not fall lower even when hot. It feels lumpy when driving at low speed. I changed the throttle pedal (second hand) faults came back after 5 mile run. Could i have a wiring fault? if so where could i get a copy of the wiring diagram for my Auto electriction

P0700: TCU Request For MIL On https://www.autocodes.com/p0700_kia.html

P0120: Throttle/Pedal Position Sensor/Switch 'A' Circuit https://www.autocodes.com/p0120.html

P1121: Throttle Position Sensor Signal Invalid https://www.autocodes.com/p1121_kia.html

P0122: Throttle/Pedal Position Sensor 'A' Circuit Low Input https://www.autocodes.com/p0122_kia.html

A.fa Romeo 156, and no year stated, now that makes this very hard, huh? for sure its 1996 or newer,
and jts 2002, you do make this hard,, ok. normal on fixya. zero inputs.

if you try to out spart the mech, that takes a book
do you want to fix a complex car book free. FSM free>?
the FSM tells you the possible on that code
and how to isolate each, why guess, do the tests. in the book.
this form is mostly N.American. and we dont have that car.
here. Fiat is trying hard to get them here, with 600 engineers. now.
oops no FSM here, cant look it up, why not join a real ALFA or Fiat forum and get faster answers. (non usa forum)
http://www.alfaowner.com/Forum/alfa-147-156-and-gt/

P1670 Electronic Feedback Signal Not Detected
and means zilch, the EFI is rife with feed back,
a really dumb, name but is common today,. running out of good names. FSM is the CURE !!!!

really you need a book.
or post the above. in the correct section , of above forum
i can't search there due to , no login.

google finds NADA, cept above.
a very hard car to service given this rarity of facts.

Return spring is likely missing

p0120 means you have a throtle position sensor problem could get expesive if throtle body is bad p0505 is same problem it means throtle idle controle valve problem hmm short bad ecm or bad throtle body hope this helps

You can look up these codes here.

If you are talking about a timing chain I think the answer could be no. I have a 2003 Spider 2L JTS which is the same engine as the 2003 156. Before that they had the 2L Twinspark and both have timing belts which need to be replace regularly along with the pulleys and idlers. Much earlier twinspark engines have a timing chain. Have a look at www.Alfa 156.net. Cheers. Brian.

Dear Allamid,

Seems to me like you need angine diagnostics performed. Your idle speed is way to high here. Mapping the engine should pinpoint and solve the problem. This is typic\lly done by nothing more than plugging a laptop into the onboard computer that governs the engine.

By the sounds of the OBD code that you have, you already knew thisabove procedure.Even so, have the Engine management unit checked, and get someone to check thermostat,engine timing,and might be worth having a full service done.

If you still dont get anywhere with this,get in touch with me andI will investigate the matter thoroughly for you,but in the meantime I do hope that this actually does resolve your issue.

yours sincerely

Ouszen

an air leak would weaken the mix of fuel to air so giving you better fuel efficiency but a poor power output.
was my last answer not to your liking, re **** fuel consumption on all fiat/alpha cars.but it is true, ask any owner........14.7 average mpg.......£205 road tax.....(tax it for a year and quadruple its value...)

Trouble code P1121 means: Throttle Position Sensor A Inconsistent With MAF/MAP Sensor

P1687 Metering Oil Pump Stepping Motor Circuit Malfunction

generally the setting for spark plugs is half turn after lock turn by hand