Technical 1.8 Problems, any idea??

[ashvj]

I serviced my 1.8 16v stilo on the weekend and since it my engine fault light is on and the car does not drive or idle properly.

I only really have a general understanding of car engines so please excuse some of the terms I use. I changed the oil filter, spark plugs, cleaned my air filter and the butterfly valve behind the air intake pipe.
After doing this I started the car and it would not idle properly, it was very unsteady, i took the car for a run and it seemed a bit juddery, as i began to accelerate the car seemed to have serious powerloss, especially around 4000rpm, it seems to drive prety much normal under 4000rpm but once it reaches this the powerloss really kicks in.

I thought it could have been a problem with the spark plugs i put in but i changed them back to the old ones and still had the same problems.

Is it something i could have done that is causing these problems or a coincidence that something has gone wrong the same time i serviced the car.

Anybody have any ideas??

 

[sixpotman]

Have you trapped one of the wires to the coil pack's?

You could do with some sort of diagnostic kit to check
the engine fault codes as this might point you in the
correct direction.

John

 

[ashvj]

Thanks for the reply, i'l have a check tonight if i can see anything like that causing a problem, i'm taking it to have diagnostics at the end of the week but just wondering if there was anything to try until then.

 

[Ffoxy]

Thanks for the reply, i'l have a check tonight if i can see anything like that causing a problem, i'm taking it to have diagnostics at the end of the week but just wondering if there was anything to try until then.

Did you use WD40 or similar to clean around the butterfly area?

 

[ashvj]

Yes, was my dad doing it, i think he used WD40, could that be the problem?

 

[Ffoxy]

Yes, was my dad doing it, i think he used WD40, could that be the problem?

That might explain the warning light & rough running / power loss.

Check / clean the lambda sensor in the exhaust manifold, they dont like WD40 should really use carb cleaner, hope you are lucky, replacements are around £60 - £80.

 

[ashvj]

How do you get to the sensor? Is it in the exhaust or somewhere next to or around it?

 

[Ffoxy]

How do you get to the sensor? Is it in the exhaust or somewhere next to or around it?

Its on the top of the exhaust manifold, middle of the engine at the front, looks vaguely like a spark-plug with wires going to it.

 

[ashvj]

Sorry about all the questions, should just wait to get home and have a look but is it something like a sparkplug that can be brushed or rubbed clean?
Your being great help, just crossing fingers thats all thats wrong, had a quick search and universal sensors that would fit the stilo can be picked up for around £30.

 

[Ffoxy]

Sorry about all the questions, should just wait to get home and have a look but is it something like a sparkplug that can be brushed or rubbed clean?
Your being great help, just crossing fingers thats all thats wrong, had a quick search and universal sensors that would fit the stilo can be picked up for around £30.

To be honest Ash I would avoid generic Lambdas & go for the genuine article to be sure, no point in having erroneous alarm possibly being thrown up (which does happen) & then having to buy the proper item or start looking for odd things that a non standard sensor might make happen.

Cleaning... well I have always replaced, but I guess a good gentle clean with carb cleaner may help but dont wire brush, nothing aggressive really.

 

[ashvj]

Thanks for the advice, i doubt i'l get the part myself anyway, i'l try cleaning it myself and failing that i'l just carry on and take it at the end of the week to the mechanic because its only a friend of my dad's who works from his garage at home anyway so wont charge much for fitment and the part so that way he has to sort it rather than me buying the wrong part and ending up still having the same problem.
Thanks for your help.

 

[Ffoxy]

Thanks for the advice, i doubt i'l get the part myself anyway, i'l try cleaning it myself and failing that i'l just carry on and take it at the end of the week to the mechanic because its only a friend of my dad's who works from his garage at home anyway so wont charge much for fitment and the part so that way he has to sort it rather than me buying the wrong part and ending up still having the same problem.
Thanks for your help.

Ask your mechanic to read any fault codes from the ECU, he should be able to if he is a decent mechanic, that should tell you if the Lambda is u/s Good luck.

 

[sixpotman]

1.8 has 2 lambda sensors one on each cat
and a third after the cats as a check. So it would
be wise to run a diagnostic.

John

 

[ashvj]

Ye he is a very good mechanic, he's taking my car in on friday as this is the soonest he is even available to even run a check to find the faults, he's just one man working from his garage and is very busy, but im prepared to wait as he is very cheap .
After i find the problem i will post and let you know what the fault was.
Will i need any type of specialist tool to take the sensor off to clean ?

 

[Ffoxy]

Ye he is a very good mechanic, he's taking my car in on friday as this is the soonest he is even available to even run a check to find the faults, he's just one man working from his garage and is very busy, but im prepared to wait as he is very cheap .
After i find the problem i will post and let you know what the fault was.
Will i need any type of specialist tool to take the sensor off to clean ?

As sixpotman says there are 3, the one on the exhaust manifold is easiest to reach & can be undone with a decent correct sized open ended spanner... BUT... a diagnostic check will tell you which one or ones to look at.

As long as your mechanic has an OBD2 code reader for Fiats he should be able to help.

 

[Deckchair5]

You'll most likely find your car simply needs a throttle body relearn procedure as the ECU has lost where the throttle valve is with you moving it around and your fault codes will probably be throttle body faults P1684 or P1687.

There's nothing to my knowledge in WD40 that would affect your O2 sensors, it's mostly Naptha, kerosene and a light mineral oil so unless you sprayed it wildly in there with the engine running or left the can in there then the very small amount required on a cloth for cleaning the throttle valve would evaporate in no time much less get all the way through the engine to the exhaust

Do a search on "throttle body relearn". You may have to do it a couple of times but you need to clear the fault codes first and that will clear the stored data
ignition on but engine not started- wait one whole minute whilst the TB finds its ranges (don't touch the gas pedal)
turn off for one minute for it to store the data in the ECU
start engine with no gas at all and let idle untouched and allow the engine to warm up to full temperature, (heater off) waiting until the rad fan kicks in is good
I find it more often works better if you have your hand on your gonads whilst doing it
Take it for an Italian style test drive

Might be worth taking a look to make sure you haven't left some bits of cloth still in the intake, someone found some ladies underwear still remaining in theirs

 

[ashvj]

with the relearn process you say about waiting for it to warm up, what if the engine is already warm before i carry out the process will it still work, because id rather drive home from work then try it rather than sit in the car park waiting for the engine to warm.

 

[Deckchair5]

yes that's fine to have a warm engine to start with

Car manufacturer's vary a lot with the "throtlle body dance" but in simple terms it's

ECU Reset,
Accel Pedal Release Position learn,
Throttle Valve Closed Position learn,
and last Idle Air Volume Learn

 

[ashvj]

ive tried everything you suggested and had the diagnostics done, and still no solution, the diagnostics came up with mass air flow sensor failure, but the 1.8 doesnt have one, but after playing about i have found a part attached on the throttle body and after taking that off i can see that one of the filament kind things on it is broken, anyone know the name of this part, is it the map sensor?