Boost Junky 1 Report post Posted February 15, 2008 (edited) Hey guys, as some of you may know I have done the m50b25 conversion in my E30. Now im stuck with an overfueling problem.. When i cold start it in the mornings it coughs and misses and struggles to idle. Then when i try to drive off under load it hesitates for a few seconds (pretty much dies) until i keep my foot flat down then it jolts back into life and revs out. Once the car has warmed up it seems to be fine. Now, however today i filled it up with a tank of gas and also about 1 month ago and whenever i fill her up with more than say half a tank it runs really really rich blows black smoke out the back and the fuel gauge drops from above 55L and uses about 10L of gas. I am stumped with what is wrong, have changed coil packs over, checked for vacuum leaks and even had it on the diagnostics The diagnostics tells me the air flow meter is faulty and the TPS is not getting low enough in resistance to switch the idle control valve on. Those are the only two errors it found. Also tried brand new plugs no difference there either Cheers, Luke Edited February 15, 2008 by Boost Junky Quote Share this post Link to post Share on other sites
Boost Junky 1 Report post Posted February 20, 2008 Also just to take into consideration I replaced the fuel filter when i did the engine conversion. I was thinking that it could maybe also be the fuel pressure regulator? Anybody got any clue or ideas? Cheers, Luke Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted February 20, 2008 Also just to take into consideration I replaced the fuel filter when i did the engine conversion. I was thinking that it could maybe also be the fuel pressure regulator? Anybody got any clue or ideas? Cheers, Luke Fuel filter right way up (and into right line from pump, not tank)? Can you check the fuel pressure (know someone with a gauge)? Have you ruled out the AFM yet? Quote Share this post Link to post Share on other sites
Boost Junky 1 Report post Posted February 20, 2008 Yea i was wondering if it was up the right way, where it says OUT on the filter the hose from the intake manifold is attached and where it says IN the hose from the tank is attached. Not yet still trying to find a 2nd hand airflow meter going to go see if there is one at the wreckers on the weekend Thanks Cam Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted February 20, 2008 Yea i was wondering if it was up the right way, where it says OUT on the filter the hose from the intake manifold is attached and where it says IN the hose from the tank is attached. Not yet still trying to find a 2nd hand airflow meter going to go see if there is one at the wreckers on the weekend Thanks Cam OK, bored and tv crap, so been googling and thinking, in between trying not to look at the half built E30 race car on Tardme... ... so it occurs to me the crap running when it's cold could well be the idle control valve not working? And on the running rich - did you ever fix this problem: http://www.bimmersport.co.nz/forums/index....c=13566&hl= are you sure that the ECU is getting a correct temperature reading? If it thinks the engine is cold, it'll run real rich... Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted February 20, 2008 (edited) Did you wire in the diagnostic socket when you did the conversion ???...because that will make it alot easier And are all the components used for the conversion for this engine?? If you have the diagnostic socket......scan it before you start fiddling AFM's will not usually come up as a fault code unless they dont work at all...and then the motor doesnt go. KGH should be about 12 @ idle and approx 450 under full load with smooth readings through the throttle range Oxygen sensors will also give you the problem you are describing Check fuel pressure too. FPR may not be working. Should be 2.5 bar with vacuum, 3.0 bar without vacuum Check TPS operation and temp sender unit readings .... this is easy to do if you can use a scanner on it Compare temp readings at the point of the sender unit with a infa red temp tool I might also add...when doing these types of conversions...always wire in the diagnostic socket, make sure you buy the engine wiring harness complete with the engine. It makes things so much easier when you have problems like this. Cheers Glenn Also make sure that if the car is manual, you are using a manual DME or vice versa Edited February 20, 2008 by botanymotorworx Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted February 20, 2008 Ooops I didnt read the question properly I see you can scan it and its giving you faults.....well theres your answer Fix those first and you should be right What scanner was it ?? and did it identify your engine correctly ??.. you must be able to drive the car with the scanner to check AFM operation Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted February 20, 2008 M50B25 dont have an idle control valve They must? They gotta have something - or some sort of air bypass to get air around the TB - otherwise they wouldn't run properly when cold. Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted February 20, 2008 (edited) They must? They gotta have something - or some sort of air bypass to get air around the TB - otherwise they wouldn't run properly when cold. I stand corrected... I had other things on my plate here when I replied. I didnt read it properly either. I'll edit my post. Its probably still not going to fix the problem though. The rest of my thread still stands...you must scan it and fix any faults before going any further. Cheers Glenn PS: I'm allowed "blonde moments" real busy here at work... was thinking E46...all in the throttle body. M50,M52 all have seperate idle control motors that react to load. A faulty idle controller can also take down the AFM and vice versa. Through the DME, engine load and cold starting is compensated for by the idle control motor...add load, lights, power steer etc...brings the idle up to compensate. The load signal also is used for auto trans operation. Edited February 21, 2008 by botanymotorworx Quote Share this post Link to post Share on other sites
Boost Junky 1 Report post Posted February 29, 2008 (edited) OK, bored and tv crap, so been googling and thinking, in between trying not to look at the half built E30 race car on Tardme... ... so it occurs to me the crap running when it's cold could well be the idle control valve not working? And on the running rich - did you ever fix this problem: http://www.bimmersport.co.nz/forums/index....c=13566&hl= are you sure that the ECU is getting a correct temperature reading? If it thinks the engine is cold, it'll run real rich... Yes very much could be the idle control valve especially when the diagnostics tells me that the TPS Sensor on the throttle body is not telling the computer to switch the Idle control valve on only thing is ithat i find this strange only when the car is cold that it misfires and dies Nah didnt fix the running rich issue either Did you wire in the diagnostic socket when you did the conversion ???...because that will make it alot easier And are all the components used for the conversion for this engine?? If you have the diagnostic socket......scan it before you start fiddling AFM's will not usually come up as a fault code unless they dont work at all...and then the motor doesnt go. KGH should be about 12 @ idle and approx 450 under full load with smooth readings through the throttle range Oxygen sensors will also give you the problem you are describing Check fuel pressure too. FPR may not be working. Should be 2.5 bar with vacuum, 3.0 bar without vacuum Check TPS operation and temp sender unit readings .... this is easy to do if you can use a scanner on it Compare temp readings at the point of the sender unit with a infa red temp tool I might also add...when doing these types of conversions...always wire in the diagnostic socket, make sure you buy the engine wiring harness complete with the engine. It makes things so much easier when you have problems like this. Cheers Glenn Also make sure that if the car is manual, you are using a manual DME or vice versa Strangely enough I didnt need to wire in the diagnostics plug where as on alot of other forums I have read that you need too? But anyway it worked and we diagnosed the setup and the only issues were the TPS not comming down enough in resistance to switch over to the idle control valve... As for the conversion I received the ECU/Loom/engine etc all as one package however, that motor (E34) was bung so bought another e36 motor which just has a different oil pan and everything else pretty much swaps straight over. So the e36 motor is running off the e34 ECU but they have all the same sensors and ignition/fuel setups. Could the fact that the ECU is from an AUTO BMW cause a problem? Ooops I didnt read the question properly I see you can scan it and its giving you faults.....well theres your answer Fix those first and you should be right What scanner was it ?? and did it identify your engine correctly ??.. you must be able to drive the car with the scanner to check AFM operation It was the latest BOSCH wireless scanner whatever thats called? A nice fancy metalic green unit that plugs into the car end. We did not drive the car with it plugged in so maybe thats an option. So to conclude heres what i have done: - Swapped coil packs over - Had brand new BOSCH Super 4 plugs in and now have brand new NGK Factory plugs in - Swapped Idle Control valve over for another - Swapped Throttle Positioning senser over - Swapped Fuel Rail, Injectors and FPR over - Checked for vacuum leakse - Checked for cracked head only by seeing if the water system is milky tho... - Brand new fuel filter when conversion was done NB: Exhaust manifolds only have about half the exhaust studs installed cant get the others on will try this weekend and the charcoal canister is also missing. Also there is a water or vacuum nipple next to where the water temp sender and fuel temp sender sensors are plugged in under neath the intake manifold up the front of the head, is that meant to be a water hose or vacuum hose comming off there? What gets me the most is that when i put a certain ammount of fuel in the car it makes the problem 10x worse... Like when i goto start it after I have put gas in you hear a loud POP noise come from under the hood every now and then could that be because i dont have all exhaust manifold studs in and its blowing excess fuel out between the head and manifold? Cheers, Luke Edited February 29, 2008 by Boost Junky Quote Share this post Link to post Share on other sites
