Technical  Help / Advice , necessary

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Technical  Help / Advice , necessary

Duke11

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Hey there guys , good evening! I wanted to ask for some advices,help. I have a Grande Punto from 07'
Can someone make a photo of how the lambda sensors are connected? I put two brand new one's from Bosch . Perhaps , because of the connectors are the same I have put them the wrong way around. The engine light does not come on ,but there are stored fault codes if red with MES .
P1141-1B , P1135-1B , P0136-13 , P010-13

Also, sometimes the car will struggle to rev up in 4th and higher gears from 3800 till about a little over 4000 , then it would just snap and accelerate like there was no problem. Note,if I quickly pop the clutch I can fully rev the engine easily , and with lower gears the problem does not appear, what could be the culprit of this? Perhaps, a starting to fail alternator? The Spark plugs are all new and same with the ignition coils (Bosch) that got recently installed. I found a guide on forums and will check the earth ground points tommorow ,because ,last but not least sometimes the steering wheel warning light comes on and says to check powersteering , although it works. Mystical "Airbag failure" notifications , random ESP messages (sometimes the traction is disabled , but restarting the car the problem goes away) , Hillstart assist not available ...

So can someone send a picture of the wiring under the air filter please? Thanks in advance!
 
Year
2007
Ha, I can't see a factory LPG on the Grande Punto, which means it's an aftermarket installation. So will be much more complicated to analyze. Some LPG specialist might have messed up the lambda sensors connections. No idea how such aftermarket installations work.
 
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Ha, I can't see a factory LPG on the Grande Punto, which means it's an aftermarket installation. So will be much complicated to analyse. Some LPG specialist might have messed up the lambda sensors connections. No idea how such aftermarket installations work.
Hm, this might could turn out to be culprit , when I bought the car, I noticed the weird 'tweak' at the connection and removed those 'aftermarket' wires and just fitted new lambdas, unlucky for me whilst at rage I seperated the wire so much that now there are left different two colored wires not red and black, in that loom actually are running three not two wires, one of which is directed to negative terminal of battery... so I guess, I need to figure out wiring and do the same like it was just with my new lambda? I guess, because how could it previously passed the MOT's then... Also , this tweak was done to the upper sensor, right ?
 

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P010-13 looks to be a digit short
yes it's P0130-13 , my mistake mate.
both codes correspond to above and below sensors sitting at "open circuit" and two other codes say the heaters dont work ,where I know for sure they should work, because parts are brand new. Also, with my tens of times connecting to obd rarely but a P0621-15 code has been present (Alternator D+ short to +V or open circuit) , that might could possibly be of connecting to the ecu while ignition key is only @ on position without engine running but I'm willing to take a leap at fitting a new alternator
 
All four error are the wrong values seen by the ECU

Each O2 sensor should have 4 seperate wires going them

There shouldn't be any wires joined together or jumpered

I have no idea what going on here

If you peel the covering back and tell me what the wire colours are, should be something like
Pre cat. ............. Post cat
1 Yellow........... white and yellow
2 Green white ............ green black
3 Yellow green ............ brown green
4 Blue red. ........... Blue red

Pin 4 also goes to evap solenoid
 
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I have no idea what going on here
Aftermarket LPG installation managed by a 'magician' :D

The engine management eLearn doc attached.

The cable colour codes are here:


These docs are for factory settings (without the aftermarket LPG installation).
 

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Lambdas: https://aftersales.fiat.com/elearnsections/main.aspx?nodeID=199008218&languageID=2&markID=1&modelID=199000000&valID=199000004&prodID=199000000&modelName=Fiat - 199 - Grande Punto&langDesc=English&sectionName=Impianto Elettrico&validityName=1.4 16v
If you want to compare component locations, YOU do the work. Use Google (images) and find the picture of Grande 1,4 16V with lambdas (and wiring). It should be hard to mix both lambdas, top and bottom one (before and after the "cat."), but for sure, there are "talented" morons like that in the automotive field.
Top (bottom) 5 in the industry, the most stupid/incompetent types of shops are: wheels & tyres / exhaust / LPG workshops / quick lube, oil changes / car wash, detailing. Go figure.

Quick Google search. Obviously, the wiring for top sensor is near the top of the manifold. For the second must be lower. That's all. No "mystery" here. You can always disconnect one sensor and see what's the reaction of the ECU and OBD2 (MES). Where is the change or a fault code (before or after the cat.).
Top_Sensor.jpg

Top_sensor_wire.jpg


Weird errors like "ABS / ESP, Airbag, Hill holder" are related to the bad power supply, in most cases. Bad alternator, battery, bad "earth/ground", corrosion in the main fuse/relay box. Who cares you have a brand new sensors - wiring can be bad (so ECU tells the truth this time, you can follow the fault codes).

There was an option for factory LPG (or CNG of course) in Grande, depends on country I guess. And 8V units for sure (16V I don't know).
Both factory and aftermarket LPG installations may use OBD2 (CAN lines) and/or lambda signal to adjust the LPG dose (injection time).
Besides intercepting petrol injectors signals (principle of operation of modern LPG), it means, that LPG can interfere/spoil those circuits.

Any problem in the 2000-4000 RPM range, may be related to the VVT operation. Besides basics like ignition, fuel, timing, others (MAP, temperature, lambda).
 
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Before we worry about anything else

We have 4 error codes all relating to the signals being seen by the ECU as wrong

Such as P0135

Screenshot_20250214-123149.png



Which It's telling us there's a fault in the wiring, O2 sensor, feed to the O2 or ECU (unlikely)


We need to clear the codes, to make sure there not historic

If they are present or come back, assuming they do

We have this

Screenshot_20250214-121801.png


We need to check the wiring, voltages and so is voltage getting to the heater, is the ground side switching working, resistance through the element and so on

O2 sensors are physically the same, regardless of which way round we shouldn't get a heater circuit fail

I understand the LPGs need to tag into this sensor to control it's fueling but I can't see enough to come to any conclusions as I can't see the correct colour wires I expect in the photo


It's a job for a test bulb or multimeter, until this is sorted we don't need to look any further or complicate the issues any further,

The first thing to do is look at the loom further up tell us the cable colours, we can then start testing things
 
Wires here should be high temperature version, insulation and wire material = it doesn't solder to the copper normally (with regular tin-lead)!
So this "solder" joint on the picture is a bullsh*t right away. The LPG "specialist" was smoking a joint possibly. Solder sleeve is not even fully melted. And strands, spikes of copper wire are protruding, piercing through the insulation. You shouldn't do any soldering in the car anyway. Crimped connections are preferred.
Solder_not_fully_melted.jpg

11776-large_default.jpg


Most gas installations are not tuned properly and can kill the engine slowly (eating the valves/valve seats, killing the lambdas and cat. converter).
That's why it's crucial to do the MOT tests (or equivalent in your country), exhaust gas analysis - don't cheat, do not try to avoid it.
So if they managed to mess-up the wiring, other things can be wrong too. But first things first...
 
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Hey good evening lads ,thanks for the great info input.
koalar: Thanks a lot , Indeed I had them lambdas other way around connected (oops) The connections seem to have no deal with the aftermarket wiring tho' currently the lambdas are wired without that 'fix'
green vanper: thx 4 the info collection :)
GrandePuntoPoland: aha, thank you Mr.Anger :D about the lambdas,don't know why in second picture they both go on one location because on mine the second sensor downwards after the kat , I figured it's the alternator aswell. looks like I have driven many thousands of km's with not fully operational alternator! Those lights started appearing just when I installed new lambdas and ripped those aftermarket connections away.

Pretty much what is said about Lpg is true but I hope the damage is not done so much
 
It run's okay,the power steering pops only as notification technically it functions and is present ,I'm still waiting for alternator to arrive, then I'lll be able to tell if there is change in performance , while it's idling you can clearly hear buzzing sound coming from engine bay.
Also, does anyone know what is the product code for exhaust rvs donut gasket ?
 
I thought some Punto experts would have been along, by now

Also, does anyone know what is the product code for exhaust rvs donut gasket ?

It was my understanding that the 1.4 16v of this era didn't use a doughnut, and used this type instead

FIAT 71736864

Screenshot_20250217-141954.png


I could easily be wrong though


Also, sometimes the car will struggle to rev up in 4th and higher gears from 3800 till about a little over 4000

Is it better now the O2:are sorted


while it's idling you can clearly hear buzzing sound coming from engine bay.

No idea at the moment, we don't have a lot of information to go on

Throttle stepper
ABS pump

Both hum a bit from initial switch on but should quieten die quickly, injectors tick, loose air box can rattle but should stop if you rest your hand on it
 
I thought some Punto experts would have been along, by now



It was my understanding that the 1.4 16v of this era didn't use a doughnut, and used this type instead

FIAT 71736864

View attachment 460960

I could easily be wrong though




Is it better now the O2:are sorted




No idea at the moment, we don't have a lot of information to go on

Throttle stepper
ABS pump

Both hum a bit from initial switch on but should quieten die quickly, injectors tick, loose air box can rattle but should stop if you rest your hand on it

I have even two of those gaskets, they are leaking in the middle and clearly on both exhaust pipe and cat. flanges there is an groove. I'll figure something out.

02 is sorted indeed

No those are different hums , the one I had was like an huming sound that's generated when the alternators body is cracked
Good thing the A/C lines were empty , I removed the pump for human-like access to third bolt.
 

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No MOT , CO at idle 0.1 (0.3 is max) but @3000rpm it's 2.5
New alternator,ignition coils spark plugs,oil and filter and air filter,special LPG spark plugs. On top of that brand new catalytic converter. The plugs were last resort , while pulling out old ones I snap these pictures. Obviously ,third one is a bit oily and probably new valve stem seals are necessary, note there is no blue smoke coming out of exhaust , anyways what are opinions of you guys? I'm not a pro on reading spark plugs
IMG_0512.jpeg
IMG_0513.jpeg
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