1.6 fault codes

i just done a diagnostic test on car an had 3 codes come back,
p0300 random multiple cylinder missfire detected
p0303 cylinder 3 misfire detected
p460 fuel level sensor "a" circuit
can anyone shed a bit of light a stupid terms just as i trying to figure out if they covered under my warranty

re: 1.6 fault codes

which car is it? model/year/engine
what are the symptoms?

those type of codes are common on the 1.2 when the head gasket has blown between 2 cylinders. when that happens you get a bad misfire, and often the engine management light on the dash will flash (or stay on permanently, but usually flash in this situation to warn of cat damage).

of course multiple misfires can have other causes, such as faulty injectors or ingition coils or even HT leads and plugs.

if you tell me which car & engine it is i have a much better chance of detemining the most likely cause.

re: 1.6 fault codes

thanks for the advice jug,its a 1.6 16v dyn stilo 02.car is running sluggish an the revs aint steady when i stationary,also if i tap the accelorator pedel i get a slight hiss coming from engine as if there is air escapeing for a split second.ive no engine management light on that ive noticed,also it vibrates like crazy whilst stoped with engine running

re: 1.6 fault codes

1.6 is most likely to have an injector problem. its very common and matches your symptoms. measure the resistance of the injectors, a good injector is 16.5ohms, any less than 13ohms and i would replace them. you can measure reistances using the connector at the end of the fuel rail. centre pin is earth, other 4 pins are for injectors.

re: 1.6 fault codes

Or coil, easy to swop coil 3 to cylinder 4 to see if fault moves (P0304) as a quick check.

Fuel level sensor code is common on stilos (dont ask me why?) and mostly ignored.

Hi there,

This is my first post so I hope its clear.

My problem is with my 1.6 petrol 2001 Stilo, it has been in to several garages now and had diferent answers.

The Stilo feels as that it is running on 3 cylinders the first garage told me that it was the coil pack on number three cylinder this was replaced and the car ran fine for about 5 miles then the problem came back the next garage told me it was the injector on number 3 cylinder so this was replaced no improvement, I should say that this problem can come and go very quickly, I purchased a fault code scanner and the fault was saying number 3 cylinder missfire after reseting the MIL light the car still runs poor but no MIL light. I have tested for spark at all four cylinders both coil and plug and have a strong spark,there and done a comprssion test with positive results

Any thoughts would be great.

Cheers.

swop spark plug & coil to another cylinder & see if fault moves to that cylinder.

Hi T14086,

Have tried that 3 - 1 / 3 - 2 / 3 - 4 both coil and spark plug also checked spark plug visial condition and gap.

Cheers.

so fault remains on cyl 3? Need to scope out coil/injector pattern to that cylinder then when the fault is present.

Scope? sorry basic mechanics Im ok but this is the first time ive gone down the diagnostics route, can you tell me what this is and can I do it myself or is it wave lines etc (have been searching all and everything).

Ta.

yep, I would use a osilliscope and scope out the waveforms when the fault is present, this will determine if fault is electrical or mechanical....if pattern is ok the ecu/coil/wiring is ok so start looking at fuel/mechanical fault. If pattern not ok start looking at ecu in/outputs.

strange how it was ok for a while after no3 coil pack. was it a champion coil or cheap nasty one?

Firstly thanks for the rapid responses.

The coil was brought from a online fiat spares shop packaged lovely brand new but the brand had been rubbed off. also I had to go to the shop the other night so and had no option othe than take the car and after thirty seconds it ran lovely and I thought that the problem had gone but started the following morning on what feels like three cylinders again.

A guy down the road has a Snap-on Ethos would this machine help.

Ta.

shhould help yes but it wont read (if any) specific P1XXX codes.

Hi, I have looked at all and everything obd2 and believe that my long term fuel trim is very high 70% (live data reading) I have looked for air leaks on the inlet manifold and checked the ECT OHMs and all seems fine.
Any ideas before I get the car scoped.

Cheers

Stone me! That's high. Probably pointing to a poorly working injector. Maybe look at the electrcs to the injector if it's a new one you have in there

How are you getting on with this misfire? You need to get that sorted first. Once it is and if your LTFT is high then reset the ecu and let it find out the best readings again. The LTFT is a long time average so if it's way off base it'll take a long time to correct unless it's zero ed and restarted

The ecu is only as good as the information it's getting so O2 sensor readouts would be next on my list. Also any exhaust leaks would throw out the O2 sensors reading too as would a misfire

Your ECU thinks the engine is running very lean from what it's being told at the exhaust so it either IS lean or it's being told incorrectly that it is-take your choice but you have to sort out your misfire first

Hi,
OK searched for missfire again with no joy, swapped coils, swapped plugs checked for spark (good out of cylinder) compression check (good) ran for 5 mins looked down bores and cylinder 3 wet. no MIL light or fault codes but still missing on cylinder 3. Last night while the vehicle was at idle it decided to run lovely and then I stood there talking to it (going mad) then 2 mins later decided to run like a bag of nails again.
I have copied the live readings below if anybody can notice anything that stand out to be not right and what the possible fault could be.

DTC-CNT 0
FUELSYS 1 CL
FUELSYS 2 N/A
LOAD_PCT (%) 2.7 - 3.9
ETC (C) 70
SHRTFT1 (%) -9.4 - 14.1
LONGFT1 (%) 68.8 - 71.1
MAP (KPA) 36
RPM (/MIN) 855
VSS (KM/H) 0
SPARKADV -3 - 13
IAT (C) 30
TP (%) 2.4 - 3.5
02SLOCB1S12---B25-----
02B1S1 (V) 0.180 - 0.755
SHRTFTB1S1 (%) -10.2 - 10.9
02B1S2 (V) 0.040
SHRTFTB1S2 (%) 0.0

Any help would be great.

Cheers.

It's only your LTFT that looks odd and that's most likely because of your misfire. I'd say it still looks like your injector or injector circuit wiring to cylinder no.3. I'd check for poor contact at the ecu or at connector D81

I presume you're zero ing your LTFT when you reset your MIL and it's going straight back up to ridiculous amounts again
What fault code are you getting exactly? Is the fault code just misfire No 3 and not mentioning open circuit on injector 3?

How is your coolant level keeping up? A head gasket gone can squirt water into the cylinder, cause a misfire and make the bore wet. Try running it with the coolant reflll cap off to prevent system pressurisaton and see what happens

Findings,
stripped down to get at the injector plugs and checked injector ohm all mid 14s, checked contunity through all injector cables to D81 and then to the ECU plug all good, swapped injector 3 and 4 to see if missfire moved and also swapped coils and plugs again put back together and NO joy car ran poor with high LTFT levels then with no obvious reason ran lovely looked at live data and the LTFT had dropped to around 50 and the STFT had dropped to -55 then decided to run poor.
I dont have any fault codes coming up also i have used alot of fuel.
The coolant level is fine with no loss.

Decided to give up for the evening and moved her out of the garage and went up the road to turn around then ran lovely at higher revs then pulled up outside house then 20 seconds later ran poor, the exhaust sounds as if its blowing in the part behind the flexible piece but no obvious leaks.

Any thoughts.

Im very thankfull for the help that I have been given so far and hope that in the future I can help others as Im getting to know the ins and outs of the Stilo engine bay lol.

Thanks

checked lambda readings yet (sorry if mentioned...too tired to read back through thread)

What fault code are you actually getting?
Does it feel like it's running on 3 cylinders only at tickover or does it do it on occasions when normal driving too?
What mileage does the car have?
Check out the pre cat lambda heater circuit for continuity (the 2 wires that are the same colour) should be low resistance below 20 ohms usually
Can you post up the readings or a graph of your typical lambda live readings at tickover?

With an exhaust leak the car can't analyse the correct exhaust gases coming from the engine and the ecu is overfueling to compensate although why this should affect just cylinder 3 is a mystery.