help please,..:worship: :worship: :worship:
my 1.8 hlx has a problem,.
the car idles at about 750-800rpm,when driving the car it hesitates to pull off,normal driving is ok,but if i get to a hill..forget it.it seems to be ok in the morning,i.e auto choke,but then it just goes down hill.when stood still the temp gauge goes just bellow halfway and the fan kicks in,when im driving the temp reads about 2 lines from cold/the bottom.
i have changed,oil and filter,air filter,plugs ,coil packs,fuel filter,and the air flow meter..and i have had 2 diagnostic checks both have not found a fault.:bang:

any ideas guys,
alex

Lambda Sensor?

dealers are useless, if the examiner doest tell them what they need to know they're lost.

since it is fine when cold i would think it is the lambda sensor, plus dealers are known to have trouble identifying a faulty lambda (doesnt show up on diagnostic because there is no fault code)

thanks for the advice ,..
would this also give me the 750-800 rpm idle problem,..it just sounds like the car is searching/hunting,?
i have read many posts like mine where the lamba sensor is mentioned.so this is the next port of call i guess.
i drove to work this morning"about 5 miles".,the car gave lots of hot air but the temp only went to the first notch on the gauge..very strange..
cheers
alex

alex80beck said:

would this also give me the 750-800 rpm idle problem,..it just sounds like the car is searching/hunting,?

Click to expand...

that is a normal idle rpm when warm. the first start on a morning it should be slightly higher (1000rpm minimum even this time of year). if it isnt higher on a cold start then the coolant temp sensor is a possible fault, and would also explain the hesitation and lack of performance.

alex80beck said:

i drove to work this morning"about 5 miles".,the car gave lots of hot air but the temp only went to the first notch on the gauge..very strange..
cheers

Click to expand...

that is also normal

i would test both the coolant temp sensor and lambda sensor before replacing anything (you've already spent enough by the sounds of it).

the resistance of the lambda sensor heater should be 4.5 ohms (rage 4-5 is fine). measure the resistance across the 2 pins on the connector that are on the left hand side when you hold the connector so that the 2 slots are at the bottom. you cant test the probe with a multimeter (well you can but its complicated )

you can test the coolant temp sensor by removing its connector when engine is cold and measuring resistance, then start engine and check that resistance decreases as the engine warms up. also check that a 5v signal is getting sent to the sensor.

ill give them a check but the temp sensor is a new one, i fitted it about 5 days ago.
as for the lamba sensor ill get a new one.fiat or motorist store..?what sort of price am i looking at,..
its funny the car sounds like a subaru/rs cozzy when i drive it,.,.like i have a huge air filter on it even though its standard..
just wont go like it should..lol
when i said it idled from 750-800,its l;ike the needle bounces,it isnt fixed..up,down,up,down..oh and yes it goes above 1000 in the morning,think its about 1300...
many thanks guys,and jug in perticular..

alex

right that changes everything, the idle rpm when cold shows that the coolant temp sensor is definately fine.

i think the most important clue here (that i wish you mentioned before ) is the noise. that suggests you have an exhaust leak, causing a loss of back pressure, which would kill performance (especially up hill for exmaple due to loss of torque) and would also make the idle erratic.

i feel faily certain you have an exhaust leak, probably at the manifold (check for leaks between manifold and head) or downpipe (check for leak at flexijoint).

sorry about not saying,but the thing is it doesnt do the noise in the morning when its running fine,it sounds more like air,either lack off air or to much air and not enough fuel to mix with it,maybe because the lambda sensor is not working?
in the morning/cold its fine..after 5 mins when it warms up a little it starts then,plus with the car sat still i can floor the throttle and no noise is made,just seems to be underload when its warm.
im thinking it could be the lambda,but i guess its gonna cost me to find out..lol

the joys of motoring...
alex

well the lambda takes 5 mins to start working so its definately something to try. they cost approx £50-70 usually. you cna get a universal one cheaper (4 wire) and then fit it by chopping the wires on your original sensor and connecting them to the new sensor. that is the cheaper option.

jug...:worship: :worship: :worship:
i owe you a beer mate,..
i have changed the lambda sensor today,omfg what a difference it made.it now pulls away miles better,
i do think the exhaust has a slight blow aswell,up front flexi maybe,ill have to check it out,as when i back off the revs it pops a little,and im getting a bit off noise up front.
i did an ecu reset after fitting the lambda and it seems very good,hopefully better when i find and fix the exhaust..
cheers a flippin million
alex

right change off plan,keep the beers on ice..
the car is the same,it was ok for about a day,but today i went out driving the car,girlfriend 2 kids..and to be honest my 1.4 was better,uphill it isnt doing anything,1st gear 6,000rpm and it struggles..it just will not go..
i have had 2 diagnostic checks,air flow sensor,coil packs,service,lambda sensor,the exhaust isnt leaking,it sounds like it cant get enough air,or too much air..just makes a loud grumble when you rev it...im lost now and the swine will be sold if i cant sort it out,...
anyone......

********. so it worked fine for a day and now its back to normal. that is most likely to be an intermittent sensor fault, which a fiat dealer should be able to identify during a diagnostic, but that hasnt happened in 2 attempts so dont waste time and money getting another diagnostic.

where do you live? i could take a look if you're in the north east.

hey jug,im in manchester..
today i cleaned the crank sensor,and put my original coils back into the car,still the same..i did a comp check on the pistons..results are ..14..14..13.5...14.5...
i took the rocker cover off to check if any valve springs were broken but nothing,it all seemed ok.i drove uphill with gf,2 kids yesterday and it just wouldnt go at all,but down hill its like poo off a shovel...
maybe fuel pressure problem,?im almost out off ideas,or the knock sensor?
lol..
cheers jug,..

alex

lets start form the beginning and take a logical approach.

considering the fact that the problem only occurs once the engine reaches normal operating temperature, my list of strong possibilities would be:

injection:
-lambda sensor
-charcoal filter solenoid valve (may be stuck open, preventing lambda signal from been used to adjust fueling)
-throttle position sensor
-coolant temp sensor

ignition:
-MAF
-crankshaft position sensor
-coolant temp sensor

now you need to see what you can cross off the list, what do we know for certain is working ok.

the change in ignition advance when cold is dictated by stored parameters in the ecu, and the paramter to use is dictated by the coolant temp sensor. we know the coolant temp sensor is working (on the 1.8 it is a single thermistor so working gauge = working sensor) so we can be fairly sure that a problem that only appears when the engine warms up is very unlikely to be an ignition problem. that rules out MAF, CPS & coolant temp sensor.

so we're left with
-lambda sensor
-charcoal filter solenoid valve (may be stuck open, preventing lambda signal from been used to adjust fueling)
-throttle position sensor

now lets add the fact that you did not find faults in 2 diagnostics, well unfortunately in this case that does not help because none of the 3 possibilties would usually show up on a fault code read. however that does suggest the 3 possibilities are still strong contenders.

also consider the fact that you've replaced the lambda, and that leaves
-charcoal filter solenoid valve (may be stuck open, preventing lambda signal from been used to adjust fueling)
-throttle position sensor

so what should you do? well if it was me and i'd narrowed it down to 2 probable faults on parts that cost less than a fiver at a scrapyard, i would replace them both just to be sure. you should also make sure any exhaust leak is fixed as it can have a very big effect of torque, and your lack of hill climbing ability suggests your engine is lacking torque. (however fueling will affect torque as well so do not assume there must be an exhaust leak, although the loud noise would suggest it is the case.)

damm dude you know your stuff..lol
well the throttle position sensor was my next port off call,also
it is doing it when cold,but not as bad,either that or i dont know it when i get up,either way ill change the sensor,and see if the idea works,..
cheers jug
alex

howdy jug,
well flowing upon the last reply..i thought i would test the fuel pressure system..it runs at 2.9 bar...and goes to 3.5 with throttle opened,,
the exhaust is blowing,..:bang: :bang: :bang:
so maybe it was that all along,...will a brava exhaust fit,..i have been on exhaust systems online and the part numbers for both systems are the same on a few different sites...also the girlfriend said as i pulled up she could smell petrol/fumes...so maybe this is the answer ??
will keep you posted
cheers m8
alex

yeah brava exhaust is the same.

dont buy online, local exhaust places will be cheaper. the price you pay for delivery online will pay for fitting at a garage. shop about and do not go to any big chains like quickfit.

also check to see where the leak actually is, could be the manifold has come away from the head or the bolts holding down pipe to manifold are loose. best to make sure before you go spending money on anything.

hello jug
well i have replaced the full exhaust system including the cat.
the car drives much smoother now,but still lacks in the overall power.
so your thinking i should change the throttle sensor and/or the purge valve.
well ill pop to the breakers and get them,hopfully things will go well.
now the exhaust is quiet i can hear more from the engine,when slowing/de-celerating it sounds like the engine isnt getting enough air?like a sort off strange noise,like you would hear on a loud backbox on a nova..lol
like a sort off brr brr brr brr,if you can figure that out..lolbut its coming from the engine/air.
anyway ill get some more sensor's and go from there.
happy days dude
alex:slayer:

Air inlet leakage?

Think I have one on my 1.2. it tends to "hunt" when it starts for the first time and holds back a bit for the 1st few mins at low rpm. My mate said check the inlet pipework for leaks. Will see what I can find.

the noise is still there after an exhaust change, so it is definately something we need to investigate further.

Skate2create said:

Air inlet leakage?

Click to expand...

that was my first thought.

interestingly, your idle rpm when warm is actually a little bit low (should be 850 in an ideal world, but 800-900 is expected), and an inlet leak would usually cause a high idle rpm.

however that could still mean you have a small inlet leak, and the ecu is compensating for it by increasing the fueling and advancing the ignition, and although it is doing this well, there is still a noticable difference compared to the expected idle rpm. this leak would cause power loss when driving. rather than replacing any sensors at this stage i think its best to resolve this noise issue first.

a vacuum leak will almost always show unusual MAF and lambda readings during a diagnostic, but not neccessarily causing fault codes, which is why a code read is so crap and sensor values need to be read in real time to really diagnose what is happening.

i would thoroughly check for a vacuum leak on the intake. rev the engine while you have your head in the engine bay. check all vacuum hoses.

also check your sparkplugs are all airtight, you may laugh but this could easily be the problem. check with the engine running and the spark plug cover removed. feel for air movement around each coil.

if you get the car in a garage a cigarette can help, you'll more easily see unexpected air movement, especially with the engine getting revved