Fiat 500 0.9 twin air
I wonder if anyone can help me with a problem I have been in the motor trade for 45 years now too long to be honest but we try to keep up to speed
My problem one of my customers has rand over a stump and put a big hold in the sump as soon as she heard the bang she moved the car to the side of the road and switched off the engine then had it recovered to my garage but the car has not started since it was turned off
So removed the damaged sump and took off the oil pick up and checked it I fitted a new sump and filled with new oil not took the filter off as it had been service only a thousand miles before
So I did a diagnostic check and the fault is P1524-79 Spark Plug anti fouling diagnosis- mechanical linkage failure.
I have spoken to lots of my pals in the motor trade and no one seems to have a clue the Tec at fiat said have I tightened the sum bolts so I gave up on them
So if anyone can put an old mechanic I would be very grateful :bang:

Is it not the fuel cut off?

peterrrr said:

Fiat 500 0.9 twin air
I wonder if anyone can help me with a problem I have been in the motor trade for 45 years now too long to be honest but we try to keep up to speed
My problem one of my customers has rand over a stump and put a big hold in the sump as soon as she heard the bang she moved the car to the side of the road and switched off the engine then had it recovered to my garage but the car has not started since it was turned off
So removed the damaged sump and took off the oil pick up and checked it I fitted a new sump and filled with new oil not took the filter off as it had been service only a thousand miles before
So I did a diagnostic check and the fault is P1524-79 Spark Plug anti fouling diagnosis- mechanical linkage failure.
I have spoken to lots of my pals in the motor trade and no one seems to have a clue the Tec at fiat said have I tightened the sum bolts so I gave up on them
So if anyone can put an old mechanic I would be very grateful :bang:

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Hi. Thats a strange one.

Weird code too.

Where are you based.. access to FIAT specific diagnostics may help shed some light on this strange code.

Charlie

Is it a stored code from the time of the incident or a new one since reassembly?
I have a vague recollection of a similar code from a twinair which had lost oil pressure from being underfilled at an oil change. Unfortunately I don't think it was on this forum, and I can't find it in my browser history. I do remember the code description was helpful on Fiat Examiner (or possibly MultiECUScan) but was confusing as reported by a generic reader. Possibly something related to the hydraulic valve operation.

Try a Fiat-specific reader if possible.

If not, and really no other options available, I might be tempted to revert to bush-mechanic mode and:
Clear the code.
remove the spark plugs.
Spin it over on the starter until oil pressure light goes out a few times.
Put plugs back in and retry.

However, I am not a twinair expert, so try at own risk.

Thanks for the reply I have use 3 code readers and all come with the same fault code and relate to oil pressure my gut feeling is the oil pump I have a spark I have fuel up to the rail I feel the ECU has turned off the pulse to the injectors I thought if I cleared the fault code even if there was no oil pressure it might have fired until it picked the code up again I am going to remove and replace the oil filter and I think I will fill it with oil from the oil filter housing I was going to try and get it to fire on easy start just to see if I can get oil pressure on cranking it, the oil light does not go out on cranking but that common sometimes I was going to earth out the oil light switch to make the ECU think it had oil pressure. I have loosened the oil pipe off the turbo and cranked it and I did not get any oil to leak out But I am confused about what this is “anti fouling diagnosis- mechanical linkage failure.” I think the anti fouling will be the fuel cut at the injectors but not sure about mechanical linkage I would like to think something has been knocked off when the sump was damaged, thanks for any help , I am based in Manchester.

Hi.
The place recommended
in Cheshire :Lancs is an old school Italian place that member

Thebeard has used for years


My understanding of the uniair engines.. the fuel in is controlled by solenoids.

You can imagine that LOW oil pressure could trigger a NO INJECTION scenario.

Charlie

peterrrr said:

Thanks for the reply I have use 3 code readers .
thanks for any help , I am based in Manchester.

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https://www.fiatforum.com/garages/447446-garages-manchester.html?p=4247008

Thanks Varesecrazy for your reply but having spent all morning thinking about putting the sump back on after taking it off again just to double check the pickup I have spent most of the morning on the computer in the office and found some very interesting information how the twin are valves work so it looks like the oil pressure is key to the engine starting as that feed a high pressure valve block which in turn opens the valves to various degrees so by spraying easy start to try and start it will not work as the valves are shut until it has oil pressure I will post the link but it has a URL so I am not allowed to yet so I am back to thinking it is a faulty oil pump as P1524 also says Oil Pressure Out Of Range Like I said I am getting to old for this new tec I have been fixing Fiats for years and never been stumped

peterrrr said:

Thanks Varesecrazy for your reply but having spent all morning thinking about putting the sump back on after taking it off again just to double check the pickup I have spent most of the morning on the computer in the office and found some very interesting information how the twin are valves work so it looks like the oil pressure is key to the engine starting as that feed a high pressure valve block which in turn opens the valves to various degrees so by spraying easy start to try and start it will not work as the valves are shut until it has oil pressure I will post the link but it has a URL so I am not allowed to yet so I am back to thinking it is a faulty oil pump as P1524 also says Oil Pressure Out Of Range Like I said I am getting to old for this new tec I have been fixing Fiats for years and never been stumped

Click to expand...

Well just an update I hate when someone asks for helps and sometime never comes back to tell you the outcome was and like I said I have been in the motor trade for 45 years its 48 to be accurate and I have never been beaten by a fiat the new merc but not a fiat so the fault code was P1524 and depends on the reader its an oil fault or lack of oil pressure at the valve brick/head So I tried every way to blead the oil system but could not get oil pressure so last resort put the whole car back together and set fire to it
well I wanted to but my last hope was to tow the car, you would get people saying don’t crank it too much with no oil pressure but I towed it for 400 yards and the oil light went out and the second it went out it fired up and ran like a dream, well like a fiat 500 LOL ran it up to operating temp then let it stand for a while and its starts first time so if you get a code P1524 code and ran it low on oil or put a hole in the sump and lost oil the oil fix the sump change the oil and filter and give it a tow as cranking alone will not prime the engine, all the specialist I rang did not have a clue when I called so I hope this one day might help someone with the same fault, What I will do now from time to time come on the forum and give some technical advice where I can I do get people ringing me about repairs as a few customers have recommended my over the years,, Merry Christmas

Good one. Pretty sure that procedure is not in the workshop manual, but....
so much more satisfying than just setting it on fire.

Well done peterrr

Might be worth fishing out the hidden gauze filter.. as there may have been some crud picked up..potentially circulating.

Good to know that no oil pressure DOES mean no injection.

Well done again. Charlie

Hello peterrr and Thanks for your post.
I have the same problem with my fiat 500 0.9 twinair.
After changing the cylinder head gasket, my engine doesn't start and i have the P1524-79 code.
The starting motor runs but the engine fails to start.
Apparently the valve timing is good, the level of oil too.
I tried this without result:
"remove the spark plugs.
Spin it over on the starter until oil pressure light goes out a few times.
Put plugs back in and retry"
Sorry, (i'm french), I didn't understand all of your solution peterrr with towing.
You are towing the fiat in 2nd gear with contact on?
Thanks for your answer.

Jean