m52 Turbo Build

[328iFun]

Alright so I've replaced almost every sensor on the car except o2 and MAF.

At this point I'm thinking about swapping over the m52 manifold from my spare motor too see if it effects idle or replacing the o2. There's no change in idle when the o2 is unplugged, so I don't know if the o2 could create a bouncing idle or not. Couldn't find anything searching turbo builds. The o2 is new but it may have gotten oil on. Only reason I haven't replaced it yet is because of $. From what I've read the car should go into open loop if the sensor unplugged

I may also swap in the stock DME, injectors, and MAF to see how the car runs

or

should I skip all of that and do a smoke test? I'm certain all of my connections are secure under the manifold but I'm thinking there may be a leak at or to brake booster or somewhere else I cant see

please help point me in the right direction!

[Butters Stoch]

Check the MAF for oil coating. Spray the MAF with cleaner and redrive. Take care of the o2 as well.

[328iFun]

Check the MAF for oil coating. Spray the MAF with cleaner and redrive. Take care of the o2 as well.

Thanks Butters,

Zack (22rpd) and I tested the MAF for voltage last night, he said it checked out fine at around .60-.80v.

I ordered an o2 and will swap out this evening and report back, $109.00. I am broke as a joke. I hope it fixes it

[exvitermini2]

I had similiar issues with my e30 when I put it together, pulled my hair out. Finally found that the IACV was stuck, cleaned it got it freed and it was fine after that

[328iFun]

I had similiar issues with my e30 when I put it together, pulled my hair out. Finally found that the IACV was stuck, cleaned it got it freed and it was fine after that

Man, you have no idea how bad I wish it were the IACV!

I've cleaned the original IACV that was on the car and took the IACV off my spare (identical) to no avail

you got lucky

[328iFun]

Alright guys now fuel pressure gauge is bouncing and idling is even worse from fuel rail:



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[328iFun]

WOW

So I replaced o2 and Crank sensor, still have codes

P0135, o2 Sensor Heater Circuit Bank 1 Sensor 1
P0335, Crankshaft position sensor A Circuit

car is running like COMPLETE shit now

I'm seriously about to throw in the towel. I enjoyed my 40 miles of interrupted boost. But I've been simply trying to get this car to correctly idle since last Saturday

If anyone's will to buy any of this stuff, here it is, 40 highway miles: Ill let it all go for 3.5k

Complete Turbo Kit:
Precision 6262 Journal bearing
22rpd base tune with ECU and OBD connector, and time for revisions
SPA manifold T4
SPA wg tube
Turbo smart waste 7 psi spring 38mm vband
Zeitronix data logging
Eboost street 2
60lb injectors
Walboro 255
2 Scavenge pumps
M50 tapped for boost
Cylinder head with new valve seals
ARP Studs
Copper spacer
38MM BOV
Charge Pipes
Treadstone 1235 Intercooler
Downpipe
(2) SPAL Fans
Low temp thermostat
Mishimoto Rad
All hosing
Vanos tap for turbo
Turbo feed line
and more...

[crazyyardie]

Damn you really parting it out !!!!
That's sad but Pm me about Zeitronix data logging and eboost


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[crazyyardie]

U should t give so easy. It's prob something simple that your overlooking


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[bmw328m52]

I was at this point after the machine shop f*cked up my first head. I was getting zero comp in all cylinders. Had to buy new hg and head. Keep pushing bro. You have unlimited technical support from bforums.

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[jakeE36325]

Have you swapped out the o2 heater relay or checked for power at it? Might also be worth checking your timing.

[Butters Stoch]

Fuel pump could be sucking air causing the FP change. But if vacuum is bouncing then FP will bounce. Did you physically pull the MAF to check for oil ? Are you clearing codes properly ?
Disconnect the battery then drive it. Remember these cars need to adapt.

[328iFun]

Fuel pump could be sucking air causing the FP change. But if vacuum is bouncing then FP will bounce. Did you physically pull the MAF to check for oil ? Are you clearing codes properly ?
Disconnect the battery then drive it. Remember these cars need to adapt.

The car was idling pretty good. When I shut it off and then started it back up with no changes it idled terribly.

I bought a brand new MAF, no change

I've swapped the cam sensor and I still get pending codes

I've changed the crank sensor still get crank code. It's not OEM but it is new

I've bridged the fuel relay, I've connected the fuel pump directly to power.

I bled the fuel pump rail.

I've felt, shook, clamped, tightened and reclamped every single vacuum hose, clamps, manifold bolts, tb bolts that could effect idle literally 15 times and it has little to no effect on idle

I've taken the intake manifold off and checked gaskets and connections 5 times

I've swapped out the vanos
solenoid 4 times

The camshaft sensor i have 2 of them I've swapped it probably 5 times

I've plugged and verified and unplugged all manifold connections 10 times

I've tried 2 brand new o2 sensors I've spliced, respliced, plugged unplugged 15 times

I've swapped out the iacv 4 times, I've cleaned them twice

I've checked any cabling or hardware that I have come into contact with to ensure I haven't screwed anything up

I've checked compression 5 times

I've swapped plugs 2

I've swapped every single coil pack 3 times

I've temp checked the exhaust manifold for variances in temperature

I've checked vehicle voltage at battery, may need a new alt and battery

I'm starting to lose my sanity. I've spent 40 hours since Saturday chasing my tail and its worse than what it was

When I put the car back together it ran perfectly on first start caused I made sure everything was correct...

I don't get it


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[pbonsalb]

Disconnecting battery won't do anything on obd2 cars. But using a higher level scan tool to reset adaption could help.

[328iFun]

Disconnecting battery won't do anything on obd2 cars. But using a higher level scan tool to reset adaption could help.

It will barely hold idle or even start now



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[bry195]

As easy as it is to start the car and unplug the electrical connector on the IACV i would have thought you woul have done it even if its to tell me im crazy. But here goes I'll explain

even with a good iacv the idle can hunt. The OEM or even tuned IACV is has a mathematical model that tells it how much to open and close over a given amount of time based on the physics of the motor the model was tuned or developed for. Part of this model is to uses rpm feedback and other parameters to land the comanded value smoothly on the actual value with an expectancy window that we tell it to try again if it (mid move) is not where its suposed to be.

so imagine that one of the variables that provides feedback to the math model is a little off. It cold undershoot the target or overshoot the target. So the expectancy window throws it in the opposite direction. 1 of 3 things happen. On reveral it overshoots another window and throws yet another reveral at it. So it either drifts into the right window, drifts by the window, or hits the target.

so you get a decaying oscilation an increasing oscilation a steady oscilation or you hit it on the head.

if you unplug you get nothing but it eliminates the timing, fuel, and iacv compensations. If the car dies when you unplug you get to open the throttle plate idle adjust and tke a bunch of crap for touching the untouchable.

you adjust it to where the car jst stays running and decide you dont need the iacv. Or you decide im going to open it up further while the car is running and all holy hell braks loose with mixtures and rpm and then you unlug and call it good enough. Or you push through the storm and keep opening the idle adjustment and remember some smat a** was whining you forced him to write a book for an experiment that is just as likely not the same as his problem was s it is that al the same indicators led him to solve his problem this way. Touch the untouchable but only half of the tuning tables are going to work when you have the CEL. My rpm oscillation had 1 second the .5 second then .25 second intervals and then dead silence when the CEL was not on and the PID loops for fuel, IACV, and ignition stayed in 1 table and fell into the expectancy window.

the iacv retards and advances idle speed. Its a very fast continuously varable bi directional valve that is corrected by several other tables that lag the valve......thus the need for the math model to begin with.

Friction, inertia, temperature, afr, .......the model compensates for a limited amount of variation.

[328iFun]

As easy as it is to start the car and unplug the electrical connector on the IACV i would have thought you woul have done it even if its to tell me im crazy. But here goes I'll explain

Thanks for the write up.

I've tried unplugging the IACV briefly.

The car was running great with the IACV initially which leads me to believe that the its not the problem. But id be willing to leave it unplugged at this point to see if anything changes...

this is a video at idle before sh*t went south, the car was idling/revving beautifully

[328iFun]

I just got to thinking as I was reading over this thread: https://www.bimmerforums.com/forum/s...ning-Turbo-Car

Where voltage appeared to be the issue with his turbo e36.

I never really thought about it but I've had to jumpstart my car several times with my battery jumper to get it to start back up after turning it off. This has happened numerous times to the point where I've just left the charger connected to the car. I never really though about it.

I happened to put a multimeter on my battery last night after I shut the car down and it read around 10v. This morning it read around 11.50v.

Could a bad alternator cause of all of these problems? I've left the car connected to the charger with it running to boost voltage to see if it helped any, it didn't.

I do have 2 electric fans, 1 scavenge pump and then all of the other turbo accessories connected to the car

The car was idling the worst it has in awhile last night the RPM gauge would bounce all the way the way up and all the way back down?

[dkech]

I just got to thinking as I was reading over this thread: https://www.bimmerforums.com/forum/s...ning-Turbo-Car

Where voltage appeared to be the issue with his turbo e36.

I never really thought about it but I've had to jumpstart my car several times with my battery jumper to get it to start back up after turning it off. This has happened numerous times to the point where I've just left the charger connected to the car. I never really though about it.

I happened to put a multimeter on my battery last night after I shut the car down and it read around 10v. This morning it read around 11.50v.

Could a bad alternator cause of all of these problems? I've left the car connected to the charger with it running to boost voltage to see if it helped any, it didn't.

I do have 2 electric fans, 1 scavenge pump and then all of the other turbo accessories connected to the car

yes ,it has happened to me ,the alternator was bad ,it didnt charge the battery right and the car start to lean out probably because the pump has not enough power to work as it should ,i figured it out pretty quickly though because after 2 days the battery was dead and it didnt crank at all

[328iFun]

yes ,it has happened to me ,the alternator was bad ,it didnt charge the battery right and the car start to lean out probably because the pump has not enough power to work as it should ,i figured it out pretty quickly though because after 2 days the battery was dead and it didnt crank at all

Hmm, maybe onto something here. I've had this issue for awhile now, where I constantly have to let the battery charge or connect my jumper box. I should have sorted it out sooner.

Whether its the problem or not, it needs corrected

Also got to thinking about lean conditions and there are so many variables, tune aside that could cause these cars to run lean at anytime whether its in boost or not. Not a good thing

[dkech]

dont know if its the solution but it could be ,otherwise i recommend contact your tuner to dial in with the tune maybe
here is two vids of my car ,the first is normal the second is the night before the alternator die completely,check the difference in afr readings
https://www.youtube.com/watch?v=OYtlXFe3XE4
https://www.youtube.com/watch?v=QD6lkqet3S8

[328iFun]

dont know if its the solution but it could be ,otherwise i recommend contact your tuner to dial in with the tune maybe
here is two vids of my car ,the first is normal the second is the night before the alternator die completely,check the difference in afr readings
https://www.youtube.com/watch?v=OYtlXFe3XE4
https://www.youtube.com/watch?v=QD6lkqet3S8

Awesome, thank you.

What about idle? Mine may be in much worse condition than yours was. Looking at sourcing an alternator now. At least I can get that out of the way. My car sat for a good 2 years and wasn't driven much due to a wasp nest, I was stung several times. So I'm sorting all out of these little issues. But I think a charging problem may have been present then and is getting worse now. Its been so long I cant recall.

But I do know if these car don't see enough voltage throughout the circuitry, crazy things happen

Would also explain why the car ran terrible when shut it down and started it back up last night. The starter probably drained the little bit of energy that it had and then there wasn't enough to properly energize the relays.

[dkech]

Awesome, thank you.

What about idle? Mine may be in much worse condition than yours was. Looking at sourcing an alternator now. At least I can get that out of the way. My car sat for a good 2 years and wasn't driven much due to a wasp nest, I was stung several times. So I'm sorting all out of these little issues. But I think a charging problem may have been present then and is getting worse now. Its been so long I cant recall.

But I do know if these car don't see enough voltage throughout the circuitry, crazy things happen

Would also explain why the car ran terrible when shut it down and started it back up last night. The starter probably drained the little bit of energy that it had and then there wasn't enough to properly energize the relays.

after that run the idle was terrible ,i was raising the rpms in order to keep it alive,the next day it never start so i replaced the alternator ,charged the battery and everything came back to normal

[328iFun]

after that run the idle was terrible ,i was raising the rpms in order to keep it alive,the next day it never start so i replaced the alternator ,charged the battery and everything came back to normal

That is good news for me, not for you.

[dkech]

as i sorted it out i am glad that didnt happen something worse due to lean afr under boost