flyboyX's obd2 s52 engine swap blog

[flyboyx]

And a little heads up for you hydro boost swap. use as much of the e23 stuff as possible or it will NOT work! The problem with using a hydroboost system is there are all kinds of little restrictors in the hoses and if each and everyone is not properly duplicated the way it wass on the e23 you will have problems.

yeah, i would like to check that out. the only difference that i have really noticed is that on the e23 there is a restrictor in the pressure line between the accumulator and the hydro booster. it is the fitting attached between the upper booster and the pressure hose pictured below.



according to real oem, that part is a restrictor for abs brakes. it has a very small orifice of about 1/64 or less diameter. needless to say, i plan to install it on my car. as far as the rest of the parts are concerned, i can see no differences other than the hoses have different bends and lengths. i am always open to learning something new.

[flyboyx]

today was good day because i had time to work on my car for a few hours this evening. as i mentioned above, the reservoir has been mounted, it is a bit tight against the maf. i may move it a little later on.



here is a photo of the accumulator with the high pressure hose fittings mounted to it. that is the factory bracket from the e23 but turned upside down. on the hose fittings, i left part of the crimped collar where it attaches to the metal line because as you can see in the photo, those high pressure fittings don't have much of a barb on them. some of the newer fittings on the power steering pump don't have any barb at all. once i have the collars crimped on, i plan to put a couple of (tig) tack welds between this flange and the collar for good measure.



these are the fittings i came up with for the power steering rack and the ps pump



here is a photo of the e23 accumulator bracket with a notch ground out to fit the brace on the front strut tower. keep in mind that this will be welded to the frame up side down.



its a little hard to see in the crappy photo, but there is the up side down bracket welded low on the frame with the accumulator bolted on. the bracket is just below the bank of brake lines, just behind the motor mount bracket, and just in front of/and above the steering u-joint. the fuel lines and the carbon canister hose touch on the back side. there is about 2 or 3 inches of clearance to the master cylinder/hydro booster above(removed for clarity). the biggest reason for mounting it that low was that i felt i needed to stay away from the brake lines. i didn't want to weld on a bracket that had a cut out for those lines only to have the possibility of replacing one later.



last but not least, i mentioned above that i had found a place to mount the x20 and the x6031 plugs. yes, the wiring is a mess right now, but i think this mounting location will look factory professional when i get the the wiring cleaned up. the plastic piece that i mounted the plugs to is one side of the factory mz3 fuse box, cut off, and filed flat. i drilled a couple of holes in the plastic to fit the factory c101 mount on the plate that covers the fan and heater box on the fire wall. you can see in the far left side of the photo, i have also mounted the "L" brackets that hold plastic cover for the engine wiring harness.



i am always preaching about buying the entire car if possible to do your swap. these are just two examples of the hundreds of little parts that i have scrounged off the donor car. none of this stuff would have been available to me had i only purchased an engine. it would really suck to have to go out to the stealership every time you need some stupid little part.

by the way, in the last week or so, i sold another grand or so worth of parts off the donor car. other than the loads of parts i have purchased off german ebay, the for sale section of this forum, (and the other one), pretty much all of the cars i own listed in my signature have been paid for by selling off parts i don't need.

[flyboyx]

spent the lesser part of two days working on the car this week. foremost, almost all wiring has been completed. there are 3 wires (well actually 2) that i am not quite sure what to do with. see my other recent post if you are curious. i have spent lots of time with my nose back in the etms. those manuals suck! i also have the two power in wires to the ews that need connection.

a few months ago, i picked up a vibrant muffler from voracious motor sports. i liked the black powder coated 3" single inlet / dual 3" outlet muffler. since my vert is a 318, it has the single narrow exhaust outlet in the rear valance. i hate the way that looks. i figure a single outlet muffler will look like a damn ricer. thus i spent some time today widening the opening. i cut that part of the valance from one of my 325i facelift parts cars and welded it on. i'll post a pic when i get time.

since i had the welder fired up, i also welded a threaded post in the trunk to mount the negative battery cable. said cable was scrounged from the mz3.

[flyboyx]

i spent a few hours working on the car today. the good news is that i got the car to crank over!!!! still not running though. i am not getting fuel to the engine, so i have to assume i don't have the power to the pump hooked up correctly. also, i noticed that the power windows are not working. i presume this would be a k5/k7 issue. i did not have time to trouble shoot today because game 2 of the stanley cup final intervened. i don't have a tv in my shop. what can i say, i grew up outside of hockey town.

if anyone has any ideas to point me in the right direction, please let me know. my wiring diagrams are posted on the bottom of page one and top of page 2. i have my x20 pin #13 soldered to the c101 #13.

[flyboyx]

ok, so....somewhere up toward the top of this thread i posted a link that is actually a tutorial on bmw's ews. the link states that(with ews 3d) it is important not to attempt to start the car with either the ews module or the dme disconnected. the reason for this is because it is possible to get the code generator out of phase between the two which would cause a no start. up until today, i have been really concerned that i might have screwed the pooch and done exactly that during the mz3 dismantle.

anyway, in yesterday's entry above, i have stated that the car would turn over but not start. i wasn't getting fuel to the rail for one reason or another. i pulled the mz3 key out of the ring antenna to see what would happen when the starter was engaged with the e30 key. oddly enough, the engine will turn over either way. that bothered me somewhat. i would have thought removing the key would disable the starter circuit.

next i pulled out the #1 coil and plug to check for spark. when i cranked the engine, i will be goddamned that i had spark! that was good news!

I had the c101 #13 wire(violet/red-fuel pump relay) connected to the #13 wire of the x20 which is the o2 sensor wire. i un-soldered that wire and connected it to the #14 wire of the x20 (red/white) labeled ecm relay. i disconnected the hoses to the fuel rail and turned on the key. BINGO! i had fuel shooting out the lower in in a matter of seconds. i don't think this is the right connection for this relay. the reason is because may be hot at all times.

anyway, after hooking up the hoses to the manifold, and cranking the engine over, i was able to get it to run for about a second or so and then quit. the fuel pump runs continuously. when i turn off the key, it will also run for some period of time before it shuts off. i assume it builds a certain amount of pressure before it turns itself off. will have to check on that. anyway, after several attempts, all i can get out of it is about 1 second run time before it quits. i think there are two possibilities: one: with the wire i chose, cranking the engine may be turning off power to that wire. two: i have a bad fuel pump in the tank. i am leaning toward the first option because the car ran fine before i swapped engines. i am going to connect the #13 wire to the battery with a 5 amp fuse in between to see what i get.

my toughest challenge is that the wiring diagrams i have for the e30 are incomplete. i only have about 100 pages or so. there are a lot of things i cannot find when i refer to them. bastards!

the good news is that it runs! sort of anyway. it will just be a matter of doing a little troubleshooting until i get everything hooked up correctly.

to my knowledge, i think this is the first build where someone has "successfully" done an obd2 swap with ews3.

[flyboyx]

come on guys! i wouldn't mind a little advice now and then to point me in the right direction.

anyway, i wired the violet/red from the c101 directly to the battery junction block through a ten amp fuse. i also changed out the fuel pump with one from a parts car. still no luck. the engine will run for about a second and that is all. i might have some issue with the dme that once the engine starts, it senses a problem and is either taking away fuel or spark or both.

i have a peak scan tool but as of yet it seems that i don't have power to the diagnostic port, thus the scan tool does not work.

[jrdeamicis]

Send me a PM of what motor and chassis and I will shot a diagram that works over to you.

Please post a nice pin-out of your adapter.

Make sure you have the charcoal can line blocked off on the throttle body. And that you have the IAC valve completely in the intake manifold.

[jrdeamicis]

Send me a PM of what motor and chassis and I will shot a diagram that works over to you.

Please post a nice pin-out of your adapter.

Make sure you have the charcoal can line blocked off on the throttle body. And that you have the IAC valve completely in the intake manifold.

[flyboyx]

ok, i just passed a big milestone yesterday. the engine is officially running! as mentioned above, when i first tried to start it up, it would run for about a second and quit. someone on this forum suggested closing off all of the open leaks in the intake. i did that and the engine would run for about 5 seconds or so and quit. as it turns out, the problem was a fuel pressure regulator issue. to make a long story short, i simply didn't have one in my fuel system. the obd1 manifold has one located on the fuel rail but the obd2 cars have the fuel pressure regulator located under the body on the driver side. my engine wiring harness has a vacuum tube and a two wire plug that routs to this regulator. i was thinking to take the fuel rail off my obd1 manifold but that would still leave me with the issue of what to do with the plug and vacuum line. since i still have the donor car in the back yard, i just removed the assembly and spliced it into my fuel lines. now it runs so great! here is a photo of this part installed on my car.



anyway, in all the research and sleepless nights reading this forum, i have never happened across anything about this. i think it is because most everyone that maintains obd2 swaps into an obd1 manifold thus eliminating this problem.

i have all of my components located and welded into place. the relay box on the left, to the right is the battery junction block. below that is the secondary air pump. at the bottom of the photo is the diagnostic port. all of those components are firmly attached because i cut the original brackets off the z3 and welded them onto my e30. i think these are the most ideal locations to place these parts. i didn't have to modify the wiring harness in any way. i drilled a 3 1/4" hole through the battery tray to accommodate the secondary air pump. to the left i made an inch and a quarter hole so the wire to the pump could route from the relay box to the under side of the pump. if you look at the photo closely, you can see this smaller hole just to the left of the bracket. the two random white wires that come off the left side of the battery junction block are my temporary power for ews. once i get my wiring straightened out, those will be eliminated and placed in a little auxiliary fuse box pictured below.



i still have a good hand full of items to take care of before i pull the engine and send the body out for paint. mostly, i have a ton of wiring issues to finish up. i picked up this little auxiliary fuse box that i intend to mount over by the e30 fuse box to handle all of the extra circuits that i am adding. (power heated seats, ews, etc) that is an eight circuit box and i plan to add about 7 circuits or so. i selected this box because it was one of the few that i found that takes the same blade fuses found in the original e30 box. i still need to make a secure mounting bracket for this.



above i promised a photo of the exhaust cutout in the rear valance and my muffler. i finally got off my ass and took a shot of this too. please excuse the dust and the box under the muffler to hold it in place.




oh, one thing to mention: on my wiring diagrams above, the x20-c101 connection i have for the fuel pump relay is definitely wrong. i attached it to another wire and i will post a correction when i get the chance. also, i don't yet have power to my diagnostic port that i still need to figure out.

[daniel]

i am seeing this thread for the first time. it looks like you are figuring everything out nicely. congrats. i wish i could be of more help...

[e30polak]

Can't wait to switch to that black Vibrant!

[flyboyx]

i was sitting around tonight next to my girlfriend on the couch watching some chick show(with complete lack of interest) and decided that i would try to post a concise list of the parts that i used off the donor car. this entry will likely get edited a few times.

engine and accessories
flywheel
engine harness
dme, ews module, and matching key
ring antenna
x20 body side plug and as much wiring as possible.
x6031 body side plug with as much wiring from the harness as possible.
x1805 ews plug and as much wiring from the harness as possible.
a small section from the outside of the plastic fuse box to mount the x20 and x6031 plugs to the firewall
a small section from the outside of the plastic dme enclosure to mount the relay box to the fire wall on the pax side
secondary air pump.
front half of the exhaust, everything forward of the joint behind the resonators including all four o2 sensors
all of the brackets welded to the body to hold all of the components in the engine compartment.
several random ground points from various parts of the body.
fuel pressure regulator.
fuel tank pressure sender
fuel pump relay and about a foot or two of wire from the body harness
positive and negative battery terminal cables
battery
battery terminal junction block
flexible fuel lines from the body to the engine
rear differential
shifter
half of the shifter rod between the shift lever and the trans
radiator
power steering rack(mine was broken from the accident)
L shaped brackets that hold the engine wiring harness to the firewall and mounting brackets
could have used the entire 5 lug suspension from both ends but elected not to.
could have used the zf transmission but elected not to
guibo from the zf because i had the tranny tail shaft and drive shaft from an 87 eta.
shifter universal joint from the zf because it is a better design than the e30

a couple of words of wisdom about the wiring harnesses. as mentioned previously, i pulled the entire body harness out of the car. there are two wires that route between the ews module plug and the x20 plugs. seems like it would be a good idea not to cut them. they are about 2 feet long. also, the two wires that route from the x1805 ews plug to the ring antenna should not be cut. three wires in the x6031 route directly to the fuel pressure sensor. there is no requirement that these stay intact, but i elected to chase them through the entire harness and i made my own little three wire harness that goes all the way back to the tank with no splices. you could cut the plug and pig tail off each end and route your own wires if you don't want to take the time to go through the entire thing. i have used a shit load of various random wires from the body harness for wiring tasks. it is like a smorgasbord of color and you can pretty much always find a wire in there to match color and gauge whatever you are trying to splice into. by the time you cut the x20 and x6031 body side plug off, the harness is worthless anyway. might as well ride that trick pony to the end of the race.

[jrez]

Probably the best write up I've seen when it comes to using an obd2 engine for the swap.
Even though its been almost six years since I did mine, this thread is like reliving it all over again,lol.

I wish I'd had this thread available when I started mine.

Cheers'

[MIKe30]

Please don't take this the wrong way, as this thread is GREAT.

But my only question with this entire thread in mind - if I wanted to put my s52 in and keep it obd2, have my ews, rear o2 sensors, and secondary air pump deleted through software - couldn't I just have an adapter made through somebody like a treehouse racing, slap it on and call it a day? Or is there something that's part of the bigger picture that I'm really missing here?

I understand the feeling of doing it yourself and the pro's of knowing the ins and out of your car, but I'm just wondering if there is something else I'm missing and there's more to it.

[jrez]

If you could program out the items you're mentioning, it would be a lot easier.

My specific issue with that idea was that there was no one doing this for the 1998 Siemens DME that was my donor stuff. So I ended up making it work with the ews2, ZKE body electronics module, etc. Biggest job for that stuff was adding a small fuse box, as the there was no correct amp/power combination in the e30 fuse box, for the ews stuff to work.

Powering up the Doestch plugs was quite simple, as the color codes between e30/e36 were mostly identical.