Hi All.

Long time lurker, first time poster. I sort of hoped I would never have to post in here. With the wealth of knowledge you would think that most of the ailments that make an Italian car Italian would be covered.

I have a wonderful one for you.. My t-jet most mornings wants to be a little b****....

When i go to crank it over, it wont start on first try, second try and sometimes third try. It only happens when its been sitting for longer than about 10 hours. I can go to work, go to come home and it starts fine, no hesitation. Now I come from sunny Australia so its not a case of things freezing. This happened over summer where it would regularly be 20c at 6am in the morning.

I have done a few things to try and determine what the problem is and to maintain service.. these are

1. Plugs
2. Oil/filter change
3. Radiator flush
4. Air filter
5. Run all codes
6. Checks and cleaned MAP sensors
7. Cleaned injectors

At first I thought it might be leaky injectors that will fill the cylinder overnight but the car should start on 3 over 4 cylinders until it flushes out the fuel.. Maybe even fuel pump..

So then i scanned for codes. Nothing found whatsoever. Not even a lean bank or misfire code.

You guys and gals got any idea?

Have you checked the battery? I have a similar problem and fiat did a battery check and it came back "marginal". The fact it happens after sitting for a longer period of time hints to the battery too

I have tested the battery and came back ok. I have also trickle charged it all night and tried in the morning.. still no luck.

Does it crank over ok or is it cranking fine but just not firing?
I would check the condition of the earth straps. As a test run a jump lead from the -ve terminal on the battery to a clean point on the engine or gearbox casing. I've known a number of cars that were poor starters that was caused by corrosion on the earth connections.

When you say you have cleaned the MAP sensor... did it have mayo on it? (mixture of oil + water)
Just if it's been there a while... the oil would of ate away at the sensor and although looking aesthetically better... the internals of the part would no longer be effective. If you get erratic idling after you manage to crank it over... I would definitely change the MAP sensor to a brand new one... and make sure the oil breather hose is in good condition.

DrumRollChris said:

When you say you have cleaned the MAP sensor... did it have mayo on it? (mixture of oil + water)
Just if it's been there a while... the oil would of ate away at the sensor and although looking aesthetically better... the internals of the part would no longer be effective. If you get erratic idling after you manage to crank it over... I would definitely change the MAP sensor to a brand new one... and make sure the oil breather hose is in good condition.

Click to expand...

Hi Chris.

When I cleaned the map sensor, visually there was no mayo or oil on it whatsoever. It was more of a test to see if it would improve. Sure enough it didn't. This morning I checked the oil breather hose and made sure it wasn't clogged or split. it was in perfect order.

Hi Gex

It's cranking fine, no lack of crank or starter hesitating, its more of a lacking of fire issue. it will stumble and try to fire but wont. Much the reason I thought clogged injectors at some point.

Tell me, is there a fuel filter that could be blogged?

Does the lock(immobilizer) on the dash disappear???
Test to see if you have spark.. ( you could test this by yourself)
If you have spark that would mean the ECU is receiving a signal from the crank sensor; so it sends spark and injector signals.
After that you would need to do a fuel pressure test..(needs a special gauge...any garage should have one)

aurick86 said:

Does the lock(immobilizer) on the dash disappear???
Test to see if you have spark.. ( you could test this by yourself)
If you have spark that would mean the ECU is receiving a signal from the crank sensor; so it sends spark and injector signals.
After that you would need to do a fuel pressure test..(needs a special gauge...any garage should have one)

Click to expand...

Hi Rick.

Immobiliser lock disappears and I do have spark. I might go get the fuel system pressure tested. Might be up for a new pump.

did the car start eventually?

My t-jet does something similar:

-it struggles to start in the morning, and after it's been sat for 8-10 hours.
-it want's to start, then dies
-eventually starts but has no power.. so have to help it idle for 30+ seconds.
-if i try to get going it dies.

I have checked everything.. spark, fuel pressure, replaced, air filter, map sensor, cam and crank sensors, spark plugs, coils ( didn't buy them had a fiend with a GP with the same engine..same sensors.. no problems).
I have also used MES to read the values of different sensors... nothing out of the ordinary.

It always starts better after I run it until it's almost out of gas, then put some fresh gas. The next mornings it starts fine and i can get moving soon after, no more stalling.

aurick86 said:

did the car start eventually?

My t-jet does something similar:
https://www.youtube.com/watch?v=0HGIpQRwM0A
-it struggles to start in the morning, and after it's been sat for 8-10 hours.
-it want's to start, then dies
-eventually starts but has no power.. so have to help it idle for 30+ seconds.
-if i try to get going it dies.

I have checked everything.. spark, fuel pressure, replaced, air filter, map sensor, cam and crank sensors, spark plugs, coils ( didn't buy them had a fiend with a GP with the same engine..same sensors.. no problems).
I have also used MES to read the values of different sensors... nothing out of the ordinary.

It always starts better after I run it until it's almost out of gas, then put some fresh gas. The next mornings it starts fine and i can get moving soon after, no more stalling.

Click to expand...

That is exactly what it does!

The only other thing I think it could be is cam position sensor but thought it would throw a code of it failed...

Could it be automatic choke issue? Car thinks it has an open choke which affects fuel richness etc?

Matthewr1990 said:

Could it be automatic choke issue? Car thinks it has an open choke which affects fuel richness etc?

Click to expand...

There is no auto choke but there is a butterfly stepper motor though. Thanks heaps. If i get some time I will check it out and clean up the throttle body to make sure its not sticking. I will also check the connections.

aurick86 you should try this on yours..

I've already cleaned the throttle plate/ butterfly valve... it's not that.

As mentioned I've replaced the crank and cam sensors on mine.. and it still does it.
Only thing i can think of is ...bad petrol. Let me clarify:
the petrol looses it's volatility ..so it becomes more like diesel/oil... it takes longer for it to ignite. so it's almost like running lean.
Once the engine warms up a bit then the petrol evaporates better.. so it doesn't have any issues.
That would explain why it goes well with new petrol.

I've checked for vacuum leaks ( test with smoke machine)..didn't find any.
This car has a MAP sensor... so even if it would have a vacuum leak it wouldn't be affected as bad as a car with a MAF.

Anyone else got any ideas??

EGR valve sticking? If you can access it (I don't know where it is on this engine) try giving it a tap with a small hammer next time it doesn't start. If that makes it start it will need cleaning or give it a good thrash now and then.

aurick86, have you re-calibrated the butterfly valve after cleaning it?

This is a required procedure after the clean-up. I don't know exactly what the procedure is for the T-Jet engine, but I've found the procedure for an Alfa Romeo 156, it has a butterfly valve part that is very similar looking to the T-Jet one.

Check it out and see if it works, if it doesn't, try to find the right resetting procedure for the T-Jet.

http://bocdoo.com/view/4553/

yes i have tried that... no result.

Is the procedure for the T-Jet the same I've showed you in the link? I've red somewhere on the web, but i couldn't confirm it, that it could only be done with the Fiat Examiner.

aurick86 said:

I've already cleaned the throttle plate/ butterfly valve... it's not that.

As mentioned I've replaced the crank and cam sensors on mine.. and it still does it.
Only thing i can think of is ...bad petrol. Let me clarify:
the petrol looses it's volatility ..so it becomes more like diesel/oil... it takes longer for it to ignite. so it's almost like running lean.
Once the engine warms up a bit then the petrol evaporates better.. so it doesn't have any issues.
That would explain why it goes well with new petrol.

I've checked for vacuum leaks ( test with smoke machine)..didn't find any.
This car has a MAP sensor... so even if it would have a vacuum leak it wouldn't be affected as bad as a car with a MAF.

Click to expand...

Hi

Have you checked if the tank is contaminated ? could be you got a bad poad of fuel once and its causing problems in there. Somehow drain the entire tank and see what is in there, you maybe surprised.