A few problems, please help

[BaliLover]

My swap is completed, everything is hooked up, but I'm not yet on the road, the car is still up on 4 jackstands at the moment.

I have been running the car for a few days while I install things, and haven't had any major problems. Today I found a missing plug under the fusebox and I found its mate just hanging so I hooked the 2 together and went about installing my oil pressure gauge. I go to start the car for the first time in 2 days, and it throws a CEL. I don't remember it doing this before so I start to look around for anything that might have changed, and I found nothing, everything is still pluged in. I unplug the plug under the fuse box to see if that was causing problems and the CEL stayed on.

I figured I'd do the diagnostics thing on the ECU, so I pull the kickpanel back off and my heart drops. The pentometer that is usually metal and a sloted screw type isn't there, theres only a little white plastic phillips head about 1/4 inside the ECU housing. Oh well, just need a different screwdrive. I do the turn right, wait, turn left thing, and I get no flash. This is when I notice THERE IS NO LED IN THE WINDOW! Thats right, zip, zilch, nada, nothing, just an open window.

I yank the ECU out and theres a sticker on the side that says its a Nisssan Remanufactured ECU. I pull the top cover and find that theres what appears to be a daughterboard hooked up, and the back edges appear to be hotglued. There are 2 pretty good size IC chips, both labeled X38 1999. 10. 5 on the daughterboard. I look at the LED spot, and its 100% untouched, like there was never an LED installed, just 2 smooth silver dots. The Pentometer looks like it belongs from the inside, no signs of it being replaced or anything, unless they are superb at soldering.

So now I have a delima, has my ECU been tampered with to accomadate larger injectors or a different MAFS or something, and how am I supposed to check codes without an LED?

Next problem: I hooked up my boost gauge and I'm pulling almost 20lbs of vaccume, and when I rev the motor the boost goes up to like 5lbs, but it won't hold, it just drops back down to vaccume. I am unfamilar with turbos, so I don't know if this is normal when the car is in neutral, so I put it in gear (rear end is in the air) and tried it with the same results. Is this normal or is my turbo toast?

I also have 2 plugs, just outside the firewall hole that are going to nothing. I don't seem to have anything on the car or motor that would connect to them, and i think they are both 2 wire plugs.

I have pictures of the ECU and the plugs if someone cares to host them for me.

[VitaminT]

Don't know about the rest, but the two plugs are probably go to your stock/factory boost controller and the evap/perge solinoid. I don't have either of these connected and my car runs fine @8psi.

[Cyberkreig]

I'm sorry but i wouldnt want to begin to give you advice on the ECU problem.. Maybe trade it in.. or get an expert to solder on a LED?

The vaccume thing is normal.. all motors run vaccume and so will yours. I think -20 psi is just about right but someone else can check me on that. As for making boost the car will only make boost when there is load on the engine.. I am very supprised to hear that you make 5psi in neutral.. I know that my car is something like -1 psi when i rev it in neutral.

[BaliLover]

What about when I put it in first and just let the rear wheel spin? Would that still leave me with no boost?

[BaliLover]

ANyone willing to take the lid off their ECU and let me know if theres a daughter card (a smaller ciruit board hooked to the big one) in theres and if so, are there any stickers on the IC chips?

[VitaminT]

If your car is on jackstands that would still be a no load situation. you will only be able to tell when you put it on the ground and run it down the street. BTW...my car also runs about 20psi vac. at idle.

[jdmsilvia240sx]

20 psi vac is normal as far as I know. Thats what I've got along with the other 4 or 5 SR guys in my area.

[hokiruu]

you're probably fine. i have a mysterious ECU too, with no diagnostic connections where they should be, but it runs fine. on my metric boost gauge, i pull 380mmHg, also verified by my electronic booost controller. at about 2800rpm i am at 0, and boost kicks in at around 3800rpm.

[Boostedka]

I have a few SR20 ecu's sitting around. Let me know, if I can help.

[Phax]

As a few people already said, your engine needs to be under load to make boost. I too am a bit surprised that you're building 5 psi at idle. The most I can get it to is about -10 on the vacuum side.

While you guys are talking about standard vacuum pressures and what not, my car also sits at -20 when idle. I've noticed when I let off the throttle under load (ie when deccelerating from 100mph to 60mph in 4th gear), the vacuum drops to -30. Is that normal?

[Cyberkreig]

dont ask me, i get like -11 at idle??

[Hijacker]

most cars should only be pulling between -17 - -22 iHg at idle. Cyber: a low reading like that may indicate a leak near an intake port. check your intake mani gasket.

I don't know what to say about that really high reading. you might have a vac hose hooked up wrong...