flyboyX's obd2 s52 engine swap blog

[MIKe30]

yes, i thought about that too. in the end, my conclusion was that the factory engine/dme was designed to run all of those accessories (other than ews which is nothing but a complicated on/off switch). in the long run, if you eliminate the secondary air pump, o2 sensors, and fuel tank pressure sensor there is simply no way that the engine will run quite as designed. it couldn't possibly. will it run good enough? sure it will. it will beyond any shadow of a doubt suit every purpose that any of us r3vers could dream up for it. i admit that i am an anal fucker when it comes to all things mechanical. since i had all the parts, i just couldn't see any good reason not to incorporate them into my car. my plan is that when i get the wiring issues buttoned up, the car(engine) will run like a 2000 mz3 and look factory when you open up the hood. my intention is not to push my point of view onto any of my fellow members, but simply to document my path for those that wish to follow. was it easier this way? hell no! however, i do take a strong sense of pride in bringing the project to a sucessful conclusion and showing others that they too can take the road less traveled.

i didn't really have the option to delete ews for two reasons. first, every tuner (that i know of) offers ews delete for the seimens only with a stage 2 or greater upgrade except perhaps the racer's market. 99 and 00 mz3's have ews 3d. as far as i can tell, no one offers a delete for that. so, if i really wanted to delete my ews, my only option would have been to go obd1 and that would completely defeat the purpose of my project to begin with.



no worries mike, i definately encourage discussion that makes this a better thread as long as it doesn't veer off topic. for a long time there i was posting new information and never receiving any feedback. i was starting to wonder if anyone was even reading this.

Well I don't think there's any arguement that it can run just as well, if not better, without the secondary air pimp which is on there for emissions purposes or the ews. Admittedly the rear o2 sensors may be a different story. I just hope that I'm not over simplifying the process. I do understand exactly what you were trying to accomplish though.

On a side note regarding your dme, you mentioned your options were limited by the one that came with your donor car. Can't you swap dme's from any s52 car to another? Should read all the sensors just the same right? Seems silly to let your options be limited over a $50 part unless you already know what you intend to do regardless.

[flyboyx]

Hey, I just read that it's running. Nice work! That fuel pressure (or lack thereof) will get ya!

thanks jeff. you're the guy that gave me the idea to even think of that. i appreciate your help.

[flyboyx]

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.

yes, i thought about that too. in the end, my conclusion was that the factory engine/dme was designed to run all of those accessories (other than ews which is nothing but a complicated on/off switch). in the long run, if you eliminate the secondary air pump, o2 sensors, and fuel tank pressure sensor there is simply no way that the engine will run quite as designed. it couldn't possibly. will it run good enough? sure it will. it will beyond any shadow of a doubt suit every purpose that any of us r3vers could dream up for it. i admit that i am an anal bastard when it comes to all things mechanical. since i had all the parts, i just couldn't see any good reason not to incorporate them into my car. my plan is that when i get the wiring issues buttoned up, the car(engine) will run like a 2000 mz3 and look factory when you open up the hood. my intention is not to push my point of view onto any of my fellow members, but simply to document my path for those that wish to follow. was it easier this way? hell no! however, i do take a strong sense of pride in bringing the project to a sucessful conclusion and showing others that they too can take the road less traveled.

i didn't really have the option to delete ews for two reasons. first, every tuner (that i know of) offers ews delete for the seimens only with a stage 2 or greater upgrade except perhaps the racer's market. 99 and 00 mz3's have ews 3d. as far as i can tell, no one offers a delete for that. so, if i really wanted to delete my ews, my only option would have been to go obd1 and that would completely defeat the purpose of my project to begin with.

Jrez, I'm going to add t my thread so I don't hijack flyboyX's

no worries mike, i definately encourage discussion that makes this a better thread as long as it doesn't veer off topic. for a long time there i was posting new information and never receiving any feedback. i was starting to wonder if anyone was even reading this.

[MIKe30]

Jrez, I'm going to add t my thread so I don't hijack flyboyX's

[jasapp]

Hey, I just read that it's running. Nice work! That fuel pressure (or lack thereof) will get ya!

[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.

[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]

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'

[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.

[e30polak]

Can't wait to switch to that black Vibrant!

[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...

[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.

[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]

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.