Help with bov/mbc/wastegate lines

[LuckyX2]

So a while back I bought an 89 240sx with an sr20det swap for cheap cause the head was off and a valve was bent.

I finally got around to putting it all together with help from the fsm but no knowledge of how it came apart which made things more difficult.

Now I'm left with two hoses that I'm not sure where they go. (I still have nipples open on the throttle body and intake manifold) and a mess of vac lines for the wasategate/bov/mbc

I'm attaching pictures of what I have left. Can anyone tell me where the two hoses go? And how exactly do I hook up the wastegate/bov/mbc? What does the nipple on the top of the bov run to? where do i run a vac/boost line from? I do realize atleast that the the mbc has to go inbetween the boost source and wastegate but getting the bov in there somewhere confuses me a bit.

If someone could draw up a quick diagram in paint or just tell me how to run the lines I would greatly appreciate it. THANKS!



^^sorry for the blurry picture^^

[Justin35ll]

I would forget those lines go to the store and buy like 12 feet of the right size vacuum line. It's like 70 cents a foot.

This is how I ran my vacuum lines....I tried drawing it but it's not working well

So Theres 3 nipples on the Throttle body (top left, top right and bottom)

Top left goes straight to the BOVTop right goes to the fuel pressure regulator with a T in that line that runs to my boost gauge as well.The bottom nipple is BEFORE the throttle plate so it doesn't have any vacuum there, only boost so this one will be used for your mbc, wastegate line.

It's a good source for the wastegate becaue normally you don't want to run vacuum to the wastegate, only pressure

So now you take that line run it into the cabin connect it to your boost controller then run the line back to the engine bay and to the wastegate

If you already have an iple on your intercooler piping for the wastegate then forget that and just block that bottom nipple off.

[LuckyX2]

Thanks a ton!

I read that the fpr shouldn't be tee'd off of for reliability reasons. Is that true or is that a pointless precaution?

And as for those other two hoses. Any idea? The 90 degree elbow that's coming off of the back of the intake manifold is still open for me but I don't know what to connect to that and I noticed what looks to be a tap to drain oil into the bottom of the crankcase but I don't see anything to connect to that either.

[James@CI]

hey alright well as far as the line for the fpr you can tee that to like your boost gauge but now your wastgate and your blowoff valve should have their very own lines.

[LuckyX2]

I figured out what that opening in the crankcase is. Its for the oil drain off of the bottom of the turbo. I have all the banjo coolant/oil lines for the turbo but I'm missing the drain line that screws in with two screws. Uggh, now I've got to get that too, any idea where I could find one of those? maybe ill screw a threaded fitting into that and clamp on a hose.

[Justin35ll]

not sure where to pick up the oil return tube, but I'm sure you could find it somewhere..

As for the other line if I'm not mistaken thats for your vacuum booster for the brakes. Goes from the large port on the back of the intake manifold to the vacuum booster.

And the only reason you shouldn't T any of those lines is because you are at more of a risk for having a leak and causing damage by not supplying the right pressure/vacuum to important things like the fpr, wg, or bov. But T'ing off a line won't cause it to not work as efficiently as if it wasn't T'd

[LuckyX2]

Thanks for the advice. I'll hook it up your way. As for that oil drain, I guess I'll just rig something up for now. as long as it's sealed well I should be fine.

And now that I'm thinking about the turbo more I remember seeing a silver threaded male piece coming out of the oil/coolant line area that I couldn't find anything to thread onto it. I'm not seeing that in the fsm either.

BTW its a t28 on an s13 sr20det.

[LuckyX2]

http://www.frsport.com/FR-Niss....html

found the oil drain. $75....

EDIT:

I think that center line is the one im missing, seeing as the left end has female threads.
Modified by LuckyX2 at 3:28 PM 8/17/2009

[Justin35ll]

hmm yeah I can't remember what the oil drain tube looks like off the top of my head, but before you go threading something in there I would check the classifieds for an SR part out they are very common and I'm sure someone will pull it off for you. I just wouldn't want to see you having a problem with your own piece being too restrictive or somthing.

Oh wait which piece are you missing the one off the turbo of the one that goes into the block I thought you were talking about the one in the block never mind then

[LuckyX2]

Yea, I'm missing the one coming off of the turbo.

I keep thinking of more things haha. That T coming off of the valve cover? I know the one end of it goes into the black oil catch can and then into the crankcase but what about the other side of the T? I can't see anywhere for that. Was that for the EAI? Cause I know the EAI goes in right around there but it's been removed on my car cause of the bov I'm assuming.



That silver male thread in the center is what I'm talking about. Is that just a modified version of the oil drain pipe? Do I just run a hose from that to the crankcase?

http://www.frsport.com/FR-Niss....htmlThat's the oil drain pipe I'm talking about the silver male thread replacing.

Modified by LuckyX2 at 3:38 PM 8/17/2009
Modified by LuckyX2 at 4:29 PM 8/17/2009

[Justin35ll]

The other side of the T on the valve cover goes into the oem air intake tube you can kinda see it in my sig pic

[LuckyX2]

Oh, that makes sense. The guy I bought the 240 off of put an apexi filter on it and also blocked off that hose on the intake. Is that bad?

And what about that silver male thread on the turbo? is that just some kind of adapter put over the oil drain port? I haven't come across that in all my googling and looking through the fsm.

[newdude1]

Sorry to thread jack but what would happen if you were to put the waste gate line into the boost gauge line?

[LuckyX2]

So here's how I routed it; it's a little different than Justin's description in that I t'd off of the bov line and switched two lines on the throttle body.

top left nipple on the intake manifold >>>> T for boost gauge line >>>> bovtop right nipple on the intake maifold >>>> mbc >>>> wastegatebottom nipple on throttle body >>>> fuel pressure regulator

That way the boost gauge and bov gets vac and boost, the wastegate only gets boost cause the mbc is sealed under vac and the fpr is always getting boost.

And idk if I'm mistaken but as for newdude's question I'm pretty sure that would be fine to t into. Just make sure it's on tight cause if that blows loose your turbo will spool indefinitely and your motor will go boom.

Now that my motor is all wired up right I unplugged the coils and injectors and pulled the fuel pump fuse out then cranked it over to prime the oil and build pressure. After that I reconnected everything and It wouldn't start.... I pulled out my spark tester cause I smelled fuel and figured the fueling wasn't a problem. Well when I cranked it over the spark tester didn't light up, so that means the coils aren't getting power. I opened up a thread over here: zerothread?id=444681

If anyone wants to take a look at that too I'd greatly appreciate it! Thanks

[Justin35ll]

no no no switch the top right nipple and the bottom nipple immediatly.

The fuel pressure regulator needs to see vacuum, the bottom nipple only shows boost pressure that's why I use it for the mbc, and wastegate since the wastegate doesn't need vacuum.

But the fpr DOES

Just swap those 2 and your good.

But now about your ignition problem.. You checked all 4 cylinders to make sure all of them weren't getting spark right?Are you using an SR ignitor? Make sure it is wired correctly

[LuckyX2]

Just looking at the size of the nipples made me think that I had it right. The top right nipple is larger than the nipple on the fpr and the bottom nipple is smaller than the nipple on the wastegate.

How am I supposed to connect these if the nipple sizes don't match? how is it possible to use one piece of hose on two differently sized nipples?

Thanks.

[LuckyX2]

Well I was able to switch the lines with an adapter of sorts.Also I actually do have spark, it's just that last time I tested it the spark reader had a dead battery

After pulling all four plugs and testing them against the valve cover I can confirm I'm getting spark. Also while the plugs were out I could see all the injectors were firing but #2 seemed to be getting more fuel than the others.

So, I'm getting spark, I'm getting fuel but no start.

[Justin35ll]

i think the vacuum line size was 5/16" and it fit nicely on both nips

I would say unbolt the 4 bolts holding on your fuel rail and pull it out. Then turn the key to the on position to prime the fuel pump to see if any fuel is leaking past the injector oring seals.

I've had this problem so many times and it can cause a no start

[LuckyX2]

So I got it started (I posted how in the no spark thread) but now I've got a boost problem.

So I have all the lines set up like Justin said. I have the bottom nipple going to the mbc and the mbc going to the wastegate. The mbc is a simple in-line unit. I loosened the mbc almost all the way back and took it out for a drive to get it dialed in. We'll.... I hit 25psi

Why would I be boosting so much with the mbc loosened all the way to it's lowest setting? Is the wastegate broken?

[Justin35ll]

depends.. what kinda mbc is it. mine is backwards and the more i spin it to the left the more boost I get.

the way i tell before I install the mbc i just blew through it and spin the knob til i feel the pressure adjust..

[LuckyX2]

Its an inline spring and ball setup; Joe P brand to be precise.

Turning it clockwise tightens the spring (more boost)Turning it counterclockwise loosens the spring (less boost)

I had it turned very far counterclockwise. I'm starting to think now that maybe I just didn't have a good seal on the lines going into/out of the mbc?