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You now progressed to only Cyl.8 misfiring with
good fuel injector
good ignition plug + COP
This is edging towards low cylinder contribution.
-1- Read LTFT idle fuel trims for laggy LEAN
-2- Borescope #8 with piston lowered.
What type of oil are you running that needs you to stop for cool downs ??
no the engine as i told its 10 days that fully build but i did a compresion test and it was the same on 8 cylindres i changed even the harnes today and same thing random misfire 1 6 8 but the first who pops up its the 8 cylindre
today did compression test and it was really good on all cylindres as i told you the engine its just rebuild its ben 9 days
and no its not injectors problem or ignition coil or fuel pressure or spark plugs
today i changed engine harnes and again the same problem the last thing im gona try on monday its the ecu
is there oil in the ecu pins? I presume you used the original ecu
no the engine as i told its 10 days that fully build but i did a compresion test and it was the same on 8 cylindres i changed even the harnes today and same thing random misfire 1 6 8 but the first who pops up its the 8 cylindre
Ok my bad, its not just #8 but 1-6-8 (+ lesser randoms) on a freshly rebuilt engine tested good.
-- You do have known good ignition parts -- (we're going to leave exact timings alone for now).
--->So you have a fuel delivery Issue that causes a LEAN MISF.
Double check your fuel side real well:
low pressure
high pressure at idle
high pressure under acceleration
LTFT's at warm idle
If above is good then a full chassis fault scan could give us background story from other faults:
Oily ECU
Low voltage yoyo faults
Missing sensor data
....
It's all about casting a net to collect evidence of issues on hand.
Random weak mixture fits LEAN trim perfectly.
> THOUGHTS....
This issue may well be what tanked your engine under heavy load conditions in the first place.
Did you have rod bearings issue or what was wrong that had to be repaired??
NO italian tune-up until you engine has solid balanced contributions.
Else couple hot cylinders pay for all the lazy ones.
🤞
> Hot question worthy of interest:
what is the easiest way to measure that all Cylinders Are Evenly Contributing well +/- 15% ok.
Having good tips could prevent wear and REBUILDS.
Last edited by CaliBenzDriver; Jun 30, 2024 at 02:34 AM.
Ok my bad, its not just #8 but 1-6-8 (+ lesser randoms) on a freshly rebuilt engine tested good.
-- You do have known good ignition parts -- (we're going to leave exact timings alone for now).
--->So you have a fuel delivery Issue that causes a LEAN MISF.
Double check your fuel side real well:
low pressure
high pressure at idle
high pressure under acceleration
LTFT's at warm idle
If above is good then a full chassis fault scan could give us background story from other faults:
Oily ECU
Low voltage yoyo faults
Missing sensor data
....
It's all about casting a net to collect evidence of issues on hand.
Random weak mixture fits LEAN trim perfectly.
> THOUGHTS....
This issue may well be what tanked your engine under heavy load conditions in the first place.
Did you have rod bearings issue or what was wrong that had to be repaired??
NO italian tune-up until you engine has solid balanced contributions.
Else couple hot cylinders pay for all the lazy ones.
🤞
> Hot question worthy of interest:
what is the easiest way to measure that all Cylinders Are Evenly Contributing well +/- 15% ok.
Having good tips could prevent wear and REBUILDS.
So this is my ecu could be a demaged ecu because of the water inside?
i cleaned it the water corrusion and the ecu is really clean now but the problem its still there could my ecu be demaged
Last edited by E55amg01; Jun 30, 2024 at 12:25 PM.
So this is my ecu could be a demaged ecu because of the water inside?
i cleaned it the water corrusion and the ecu is really clean now but the problem its still there could my ecu be demaged
a good tuner can clone the ecu fairly inexpensively; I bought my three ecu's off eBay donor vehicle for about $200 each and tuner chargered $100 to clone them
So this is my ecu could be a demaged ecu because of the water inside?
i cleaned it the water corrusion and the ecu is really clean now but the problem its still there could my ecu be demaged
likely damaged but not 100% sure it's causing your issues - would love to see what a fresh ecu would do to help your situation .
was the ecu opened and poorly sealed for tuning purposes (back when they had to open it to tune it)? Or was the car exposed to water damage hence your major rebuild?
So this is my ecu could be a demaged ecu because of the water inside?
i cleaned it the water corrusion and the ecu is really clean now but the problem its still there could my ecu be demaged
There you go: this is you bad guy confirmed!
unprotected PCB shows oxidation short circuits... cleanable!
The location and landscape makes this cleanable with isopropyl alcohol + tooth brush.
Feel free to brush on the missing conformal coating except where heat pads are located.
ROHS failing solder joints...
These heavy joints are not burnt into "PCB charcoal" PCB yet but right around the corner.
This shows why pressed pins are used to prevent failed solders. Instead we get failed pins oxidation... I found that combining the mechanical hold of pressed pins + electrical solder transforms CAN bandwidth.
this cooling pad needs to be restored
Component heat is transfered to the case heatsink through this conductive material. It needs to put back. - It's much like RTV sealant squeezed between 2 surfaces: don't use too much paste that will then spread all over.
🤞
++++ WHAT CAN WE LEARN.....
This liquid damage is not petroleum.... closer to H2O water. About a quarter tea spoon amount.
It came from somewhere... through the connector!
So inspect your connector pins on both male/female sides. Expect crusties.
NEVER HOSE DOWN ENGINE CLEAN!
The MB connector seals have a limited expiration date after which wires move liquids by capillarity.
Last edited by CaliBenzDriver; Jun 30, 2024 at 04:17 PM.
unprotected PCB shows oxidation short circuits... cleanable!
The location and landscape makes this cleanable with isopropyl alcohol + tooth brush.
Feel free to brush on the missing conformal coating except where heat pads are located.
ROHS failing solder joints...
These heavy joints are not burnt into "PCB charcoal" PCB yet but right around the corner.
This shows why pressed pins are used to prevent failed solders. Instead we get failed pins oxidation... I found that combining the mechanical hold of pressed pins + electrical solder transforms CAN bandwidth.
this cooling pad needs to be restored
Component heat is transfered to the case heatsink through this conductive material. It needs to put back. - It's much like RTV sealant squeezed between 2 surfaces: don't use too much paste that will then spread all over.
🤞
++++ WHAT CAN WE LEARN.....
i cleaned them all and did new thermal paste on that area you are talking about but the issue still there i think the ecu its damaged am i right?
i cleaned them all and did new thermal paste on that area you are talking about but the issue still there i think the ecu its damaged am i right?
get a new ecu - it can only risk ongoing issues by keeping this one... plus you would have to silicone seal this one from future water/moisture - it's a losing battle
Last edited by PeterUbers; Jun 30, 2024 at 06:22 PM.
i cleaned them all and did new thermal paste on that area you are talking about but the issue still there i think the ecu its damaged am i right?
Yeah, it's a bit of uphill battle. Normally no one in his right mind dares to open modules, except us.
It's likely crusties were also on the opposite side between the connector legs.
These Bosch electronic circuits are fairly rugged design. They can handle a whole lot of abuse meaning limited crusties are not terminal conditions once cleaned.
🤞
++++ SCANNING FOR THAT.....
We don't want to crack open these working modules without solderless issues.
When scanning we can expect bogus results to alarm us.
Last edited by CaliBenzDriver; Jun 30, 2024 at 04:30 PM.
Yeah, it's a bit of uphill battle. Normally no one in his right mind dares to open modules, except us.
It's likely crusties were also on the opposite side between the connector legs.
These Bosch electronic circuits are fairly rugged design. They can handle a whole lot of abuse meaning limited crusties are not terminal conditions once cleaned.
🤞
++++ SCANNING FOR THAT.....
We don't want to crack open these working modules without solderless issues.
When scanning we can expect bogus results to alarm us.
i dare too open it because here in Albania a ecu like this in junkyard you can get it for 200-300$ and free if the junkyard guy its your friend 😂😂
tomorrow i will try the cranshaft sensor and the new ecu and update you guys
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
