beebe101
Member
I was thinking putting compressed air in one cylinder then my compression tester on a different cylinder then spark ugs in the last 2
Technical really stubborn multi air bleed or failed multi air?
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Technical really stubborn multi air bleed or failed multi air?
That sounds good. It should show.
Are the valves all close on the multiair if you're not cranking the engine?
beebe101
Member
I assume so, wouldn't the leak down test would have shown an open valve?
Yes, it would. I was just saying to make sure it is so, so you won't have false results while testing.
Generally with leak down test the manual we had on the equipment (Sun Diagnostics) when new, was no cylinder reading should be more than 25% different to the rest, although to me that seemed quite a lot.
beebe101
Member
Yea they weren't great but the were pretty equal. They were all around 50% withing like a 5% difference, I know that's not great but that's also it not running for 4 months. I feel like a bent valve or how headgasket would put it in the 80 to 90 range. I'm wondering if it's a bad camshaft like slipped love, idk nothings making sense to me.
To me the main thing of the leak test was that the pressure that was escaping could be located rather than the percentage, as in if blowing out the inlet manifold on that cylinder then inlet valves and so on. Exhaust manifold/tail pipe then exhaust valves, oil filler then past the pistons and if radiator starts overflowing then head gasket.
beebe101
Member
k ill check this weekend i wasn't sure where it was going but it wasn't bubbling up in my overflow so i guess that's a good thing lol after 6 months of looking i finally started my new job this week
The Panda Nut
Nutty about Pandas Infected by Panda virus and OPD
Im not sure it has anything other than basic oil pressure and the temp and viscocity sensors. Faults with the actual solenoids might not be able to throw a code.
I can't find much information for the USA Fiat 500, multiair version (except for Abarth 500), but if this car has:
870 Magneti Marelli Injection IAW 8GMF CF5/EOBD or similar, then it could throw quite a lot of multiair codes:
P1011 Cyl. 1 UniAir actuation electrovalve
P1012 Cyl. 2 UniAir actuation electrovalve
P1013 Cyl. 3 UniAir actuation electrovalve
P1014 Cyl. 4 UniAir actuation electrovalve
P1021 Cyl. 1 UniAir actuation electroval. drive
P1022 Cyl. 2 UniAir actuation electroval. drive
P1023 Cyl. 3 UniAir actuation electroval. drive
P1024 Cyl. 4 UniAir actuation electroval. drive
P1031 Cyl. 1 UniAir actuation electroval. power stage
P1032 Cyl. 2 UniAir actuation electroval. power stage
P1033 Cyl. 3 UniAir actuation electroval. power stage
P1034 Cyl. 4 UniAir actuation electroval. power stage
P1041 Cyl. 1 UniAir actuation electroval. drive current feedback
P1042 Cyl. 2 UniAir actuation electroval. drive current feedback
P1043 Cyl. 3 UniAir actuation electroval. drive current feedback
P1044 Cyl. 4 UniAir actuation electroval. drive current feedback
P1061 Cyl. 1 UniAir actuation electroval. signal
P1062 Cyl. 2 UniAir actuation electroval. signal
P1063 Cyl. 3 UniAir actuation electroval. signal
P1064 Cyl. 4 UniAir actuation electroval. signal
P1320 UniAir module learn
The Panda Nut
Nutty about Pandas Infected by Panda virus and OPD
They are staggering when they go, but the complications make them a big risk. I want a 1960s or 50s.. Its parts that are the problem as ever.
beebe101
Member
ok so i hooked up compressed air to cylinder 1 with the lockout tool and i could hear air coming out the intake manifold im not sure if the lockout tool sets cylinder 1 to tdc and im also not sure if my cams doing some funky stuff
beebe101
Member
ok so i took a video and ill post it ina but, but im wondering if a multi air brick can hang a valve open when its supposed to be closed because i still don't see any evidence of contact on the pistons.
Well... if the head gasket is as I said, teared open between cylinders (1/2 - 2/3 - 3/4) the air you put in cylinder 1 will go out in cylinder 2 and chances are cylinder 2 intake valve it's open.
Means there was no contact. And for me, it's more plausible there wasn't. Thinking about it from the physical perspective of what happened. Crankshaft and valves remained connected, they moved timed right, just must faster. There shouldn't have been any contact. I really think there wasn't.
I don't think it does. Theoretically maybe it could, but yours has no reason to do so.
the brick only acts as an electrohydraulic mediator for the cam shaft - if the cam isn't pushing for "open valve", the uniair module on each cylinder can't do anything by itself to open the valve.
However, if there were a mechanical problem with the high pressure actuating piston, like if this piston would be mechanically stuck in the "open valve" position and no longer move at all, the intake valve would also no longer move and be open or partially open at all times.
this is the low-pressure side, if the electrovalve receives current, the low pressure side is "coupled" and generates high pressure for pushing the valve open (the high pressure side is not shown in this video):
The oil reservoir shown is the low pressure part (it's normally sealed)
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Did I post this already?
Apparently, when there's blow back into the intake throttle body part by only one intake valve remaining stuck open because of a mechanically stuck intake valve plunger this totally messes up the air-gas mixture and/or intake pressure as measured by the sensor therefore compromising ignition for all the other cylinders, preventing the engine to start.
Apparently, when there's blow back into the intake throttle body part by only one intake valve remaining stuck open because of a mechanically stuck intake valve plunger this totally messes up the air-gas mixture and/or intake pressure as measured by the sensor therefore compromising ignition for all the other cylinders, preventing the engine to start.
Interesting to see the operation in above videos.
My thoughts are a bit more basic, with regards to the initial leak down test, assuming as is said that the multair unit cannot hold valves down on it's own, then if valve timing is correct and engine set at TDC on the firing stroke for that cylinder and crank /cam locked up, then if air pressure via the leak down test is applied, then if air is leaking out it can only be through a faulty multiair unit/valves jammed open or head gasket between the adjoining cylinder.
Normally I would have inlet manifold off and be able to see if air was escaping past the inlet valves on the cylinder being tested directly into those inlet ports related to that cylinder, so if no air escaping into ports, but air escaping into adjoining cylinder then one must assume an issue with the head gasket into that next cylinder.
Apart from exhaust valves on that cylinder also, unless they have been eliminated obviously.
I try to break things down for simplicity, so in effect an engine is basically just a pump with pistons and valves, to trace where the loss is going.
Is it possible to do the leak down test with the multiair/brick unit off the vehicle or does it hold the cylinder head tight also?
If possible and exhaust valve cam lobes are closed on firing stroke on that cylinder that is locked up to do the leakdown test, so all inlet and exhaust valves are supposedly shut on that cylinder it should be possible to determine if any air loss is via head gasket or actual engine valves in cylinder head.
My thoughts are a bit more basic, with regards to the initial leak down test, assuming as is said that the multair unit cannot hold valves down on it's own, then if valve timing is correct and engine set at TDC on the firing stroke for that cylinder and crank /cam locked up, then if air pressure via the leak down test is applied, then if air is leaking out it can only be through a faulty multiair unit/valves jammed open or head gasket between the adjoining cylinder.
Normally I would have inlet manifold off and be able to see if air was escaping past the inlet valves on the cylinder being tested directly into those inlet ports related to that cylinder, so if no air escaping into ports, but air escaping into adjoining cylinder then one must assume an issue with the head gasket into that next cylinder.
Apart from exhaust valves on that cylinder also, unless they have been eliminated obviously.
I try to break things down for simplicity, so in effect an engine is basically just a pump with pistons and valves, to trace where the loss is going.
Is it possible to do the leak down test with the multiair/brick unit off the vehicle or does it hold the cylinder head tight also?
If possible and exhaust valve cam lobes are closed on firing stroke on that cylinder that is locked up to do the leakdown test, so all inlet and exhaust valves are supposedly shut on that cylinder it should be possible to determine if any air loss is via head gasket or actual engine valves in cylinder head.
