[ALFAPAT]

156 51 plate 2.l
Problem started after fitting new exhaust , car just idles and no response to throttle, been unable to get at the car properly until yesterday.im sure the exhaust has nothing to do with it and can only be coincedental.
Now that I have the car nearer at hand , I have not been able to connect Multiscan , something about port and connection issues.
I have put Omnitec on to the car , and although its none specific with car manufacturer it comes up with codes relating to my issues.
The codes
P0120
1121
1122
0115
0340
They must be related but its not pinpointing the problem too closely.
The car just idles , no tyhrottle response and hunts ever so slightly.
I HAVE SWAPPED THROTTLE BODIES AND ITS UNCHANGED
Any CLUES PLEASE , OH CHECKED PINS ON PLUGS ON TOP OF THROTTLE BODY , UNRELATED(sorry caps), is temp sensor not working , I think unrelated , and fan inoperable. That would be the resistor as I can wire across the plugs and that works.
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[ALFAPAT]

Anyway of testing the pedal out, apart from power in , any values I can check

Ok moving on , Ihave been doing some voltage checks on the plug connecting the throttle potentiometer in the floor and the plug at the throttle body , they are all small voltages around 4 to 5 v mostly and some 1 to 2 v but not sure if these v are correct or not. I have a 147 here so may check them to compare . As you know I have swapped the throttle body with a working one at this point

 

[hdseven]

first 3 of those error codes point to throttle position sensor
0115 is temp related
0340 is cam sensor

id start with throttle postion sensor see who that goes....it may not be sending info to ecu about where the throttle is as u press it

 

[DK_ALFA_STYLING]

Try disconnecting battery 10 minutes?

 

[ALFAPAT]

battery has been disconnected a few times as well as throttle reset.
Thanks for codes, I am hoping when I look tomorrow , I have a jts out here that I may swap pedals if they are the same to prove whats what.
What does get me about the idle is the way it hunts slightly and the rhythm varies , its like its unsure of fueling , I am going to change the temp sensor as well to maybe correct this.
Would the crank sensor have a part to play here despite the fact that it does'nt pick up the fault?

 

[hdseven]

battery has been disconnected a few times as well as throttle reset.
Thanks for codes, I am hoping when I look tomorrow , I have a jts out here that I may swap pedals if they are the same to prove whats what.
What does get me about the idle is the way it hunts slightly and the rhythm varies , its like its unsure of fueling , I am going to change the temp sensor as well to maybe correct this.
Would the crank sensor have a part to play here despite the fact that it does'nt pick up the fault?

code is for cam sensor not crank

 

[ALFAPAT]

Aye I know , the point is if the crank sensor is suspect would it throw a fault if it is able to show an idle reading but nothing more.
I am wary of going down the cam route especially if I then have to commit to cambelt and tensioner.(its behind the inlet sprocket you see.

 

[gibot123]

Yeah and you have to remove the water pump [email protected] stupid place to put it :rant:
What else did you do when you changed the exhaust have you moved anything like the lambda sensor plugs ?

 

[gibot123]

Yeah and you have to remove the water pump [email protected] stupid place to put it :rant:
What else did you do when you changed the exhaust have you moved anything like the lambda sensor plugs ?
It doesn't make much sense and from discription does sound like a throttle pedal problem just odd.

 

[ALFAPAT]

yes I am going to remove it today and see if I can clean anything.

 

[chris100]

I had a similar problem, although not an Alfa, car would tick over with no throttle response, it turned out to be a faulty maf as it ran fine with it disconnected.

 

[ALFAPAT]

Hmm , I tried disconnecting and although still ran briefly it cut out, if I take the whole intake tube it refuses alltogether.Think Ill try a good one on the 147 I have before I go any further.Just sorted the fan resistor and now the fan runs at full speed as soon as its connected, I disconnected the temp sensor on the thermostat and it still runs on full speed , I always thought it should stop , another mystery to add to the problem.
Its taken me one and a half hours to remove one bolt off the pedal potentiometer, just a b..h to get at!

 

[ALFAPAT]

What a pig yo remove and I think all for nothing, after some resistance checks on the pins while off , I get redings that I would say are ok , there is one on ebay but at 34 pounds its too much of a gamble .
My conclusion after reading through the mot and the failure mot along with it the car has been welded and I think it has been spiked in the ecu.I have changed everything that I could with components off a 147 and to boot the fan is on continually and so those faults haven't cleared either.

 

[ALFAPAT]

Ok a lesson to be learnt by anyone , disconnect your battery and possibly the two plugs on your ecu.
This car is now fixed , the ecu had been fried / spiked , but not by me thanlkfully but to save anyone from damaging your ecu please disconnect everything.
So I have put a new ecu on it and everything works fine including the faults that were seemingly unrelated until the welding showed up in the work for its mot . including the temp sensor and fan etc . , very pleased.