Supercharg55AMG

Hey Guys i got a nasty problem with my E55 engine that no one can figure out,
The engine is equiped with Supercharger Pulley kit no Clutch direct pulley with a resistor on the clutch plug .
The problem is:
-On cold start the first time u start the engine when its cold u have about 30 to 50 seconds of full boost 14PSI the crazy power to the wheels ,
-After 30-50 sec the boost is gone and the gauge reads 0 PSI and the power is gone
-Turning the car off and on dosent do anything
-Resetig ecu didint work
-swaping ecu didint work
-Changing Supercharger Bypass valve didint work
-changed all the hoses around the supercharge
-done a boost leak test no leaks
-The car will not get boost untill it is dead cold sitting for a while then it will also disapear after 30-50 seconds
-Ecu has zero faults even the swaped one didint give any faults

Could it be just a tuning issue cz it has a smaller fixed pulley

[COLOR="Yellow"]After a lot of trying and stuff today we took the Engine coolant temp sensor out put it in a bowl and drove the car to make think that it is cold and the car went crazy power was back and boost was back everything worked properly what could be hapening to make it work when its cold ?

Any help is muchh appreciated .

drothgeb

You mentioned looking at a lot of stuff, and I just have to point out you didn't mention looking at IATs. You are monitoring IATs and know that your IC pump is working right?

Supercharg55AMG

Yea sory i forgot to mention that as well temps are cool and even we went a step further and built a seperate circuit for the supercharger water system to be 100% sure that its not a temperature issue and Iats and Mats were changed as they were the first suspects

drothgeb

Okay, I figured with the depth of the info you posted that would have been verified, just wanted to make sure.

Have you verified you aren't getting any detonation at temperature? What is your timing and afrs?

I'm not sure if your tuner has the ability to monitor knock or not, but maybe the ECU in this car will kill boost when it picks up too much knock?

That wouldn't make sense if you were able to pull the coolant temp sensor and get power back though.

JoeJErnst

You need to log your engine coolant temp and intake air temps via the OBDII port so you can see what the computer *thinks* the temps are. Based on your experiment with the coolant temp sensor, it sound like it might read correctly when it's cool, but may be sending a bogus reading once it warms up. The ECU is probably opening the bypass to prevent overheating.

Or you could just replace that sensor and see if it fixes your problem.

StarvingArtist

Wasn't there some crazy thing about the oil level sensor causing extreme problems a while back? All I remember about it is that it was a surprising symptom, and the correct part was hard to find. Sorry I can't be more specific, but it might be something to check.

T9ja

Yea sory i forgot to mention that as well temps are cool and even we went a step further and built a seperate circuit for the supercharger water system to be 100% sure that its not a temperature issue and Iats and Mats were changed as they were the first suspects[/QUOTE]

Did you check your IAT at cold start and after the boost disappeared? You might want to switch back to the original circuit used for the ic pump. Make sure the ic pump is not going off and on you. If I were you, I'll start by replacing the ic pump first. Any order mods besides clutchless pulley, and what size is the pulley?

FunkTron

Do you also have an aftermarket crank pulley? what size is that as well?

Supercharg55AMG

Did you check your IAT at cold start and after the boost disappeared? You might want to switch back to the original circuit used for the ic pump. Make sure the ic pump is not going off and on you. If I were you, I'll start by replacing the ic pump first. Any order mods besides clutchless pulley, and what size is the pulley?[/QUOTE]

The bottom pulley is 18cm and the upper one is 9cm as for the iat sensor its fairly colder then before the new circuit is much more efficient and the pump is bigger , even if i was this why would it work after i removed the coolant sensor from the engine

Supercharg55AMG

i think this is a good idea to investigate but i dunno how to make sure of it as i belive the only thing taht changes between cold start and normal operation is the fuel enrichmenet at cold start could the car be running lean enough to knock and enter a safe mode of some sort ? anyone know how the original ecu behaves ?

drothgeb

Are you using something like the torque app to see what the ECU is actually seeing for timing, IAT, and coolant temps?

T9ja

NO, just the sc pulley. Not going past that boost level. Want to keep it in the safe zone.

SICAMG

You need to monitor iat and see what it is doing cold and hot.

T9ja

So you have the aftermarket crank pulley, but stock sc pulley? Did you ever bleed the system after changing the pump, too?

Supercharg55AMG

yes we also added an external temp sensor to read in real life temps are fine there is defenitly no overheating, and both pulleys are aftermarket they are a full kit pulleys bolts belts boosting 14PSI and aftr the car runs about 1minute i have 0 PSI the only conclusion i can think of is that somthing is trigering the bypass valve and make it bleed the boost instead of using it , does anyone know what can make the bypass open ? Also we are using STAR MB diagnostic tool i dont know if it has data loging

T9ja

Pulleys are the only mods you have? So you have aftermarket sc fixed pulley, but in stock size because 9cm will equal to 90mm fixed pulley. If no order cooling mods besides stock cooling, I bet you, you are pulling timing, your IAT is off the roof. We still don't know your IAT readings. You need to post them so you could get the help you needed.

Does this problems started after the pulley mods ? If possible trying to go back to stock sc pulley. Many have had problems with those fixed sc pulley.

JoeJErnst

You need to find out what the ECU *THINKS* the temps are; it doesn't matter what they actually are. Get an OBDII reader and get your coolant and intake air temps from there. That will show you what the ECU is seeing.

Find a cheap ELM327 bluetooth or WiFi dongle and use the Torque or DashCommand apps on your phone to read the values. If you have STAR you may find the temperature values somewhere in there, but I don't know where to look.

Supercharg55AMG

we did that iats are fine between 30and 50 C hard revving to 7k rpm will make it hit 75 once rpm goes down its back to 30-40 and the intercooler is always cool to the touch so IAT is off the table as for
Coolant sensor its fine no spikes nothing same value as the dash value nothing out of the ordinary removing the coolant sensor it reads

and timing is between -32.5 retard full gas from idle no gear and on gear its goes down to -19 retard only and 14 degree advance i took a video of the values on the odb2 ill try to upload it somewhere and by my knowlege from my other cars these values on engine load are normal.

i want to understand why in the hell the car runs perfect if it thinks the coolant temperature is in the 20's C

ill try to upload the video with the coolant sensor outside the system thats was a pass of 1st-2nd-3rd-4th gear afr's are all over the place but the car has full power

i Honeslty belive that the car needs a good tune at this point i belive its just adding fuel on cold start that all i can think off right now Anyone know someone that has tunes for these cars ?

1st part of this is no boost with coolant sensor installed 2nd part is boost with sensor not installed

this one is a pass threw gears with the car moving on the road with the coolant sensor outside