Question When installing EBC, what do I do with the boost solenoid plug on the engine harness? Leave it unplugged? Also, my Z has crap going on with it and I’m trying to eliminate possible problems. My car is 94TT manual. Boost is stuck on <5psi max. That is before and after EBC has been installed. Car is in safe boost mode. ECU is reading DET sensor problem. Left hand O2 sensor mainly reading lean but sometimes jumps to rich for short periods. Just replaced: Coolant temp sensor Injectors to new style inc plugs Fuel pressure regulator Car only runs on cold if I push the accelerator down otherwise it will die. Runs rough as a car car be, misfiring, horrible idle. Very major problem. When hot, it runs okay with a slight sputter. I just removed all unneeded vacuums to aivs and PRVR solenoid and installed my EBC in. As stated, can’t go over 5psi for unknown reason. I’ve checked all vacuums for leaks.(can the CC leak that bad to cause this problem?) As engine temp rises, the engine will start to be able to idle by itself without using throttle, but still runs extremely rough. It’s got me buggered, only things I’m thinking will help is testing the fuel pump by pressure test and replacing the o2 sensor. Seems like a lot bigger issue than an o2 sensor though. Any advice would be awesome! Thanks
Yes Not possible if the factory boost control solenoids have been disconnected. You may have a substantial air leak, or a problem with the way your boost controller is plumbed in. Can be bypassed with something like this http://www.rgsperformance.com/product/detonation_sensor_bypass/ Or replaced http://www.rgsperformance.com/product/knock_sensor_kit/ although this is a very labour intensive task. The test procedure for oxygen sensors is to hold at 2000rpm and watch the voltage cycle. If you need a replacement I sell oem sensors at http://www.rgsperformance.com/product/oxygen_sensor/ Have you done a power balance test? What AAC values are you seeing on cold start? Your profile says NSW; if you can bring it to Northern Sydney I can have a look.
"I just removed all unneeded vacuums to aivs and PRVR solenoid and installed my EBC in." Double check what you have disconnected & reconnected in relation to vacuum hoses. 1994 models don't have an Air Injection Valve system.
No power balance test done and AAC values I do not know how to check. I’m installing o2 sensor today and hopefully seeing if this helps. Looks like I’m also looking for a boost leak somewhere! If this doesn’t fix the problem, I may be looking for outside help yeah. Thanks for the help. Sydney is a possibility, but a long way for a car that’s reading detonation and bad o2.. I’ll see what happens today for boost leaks and sensor change. Yes I have double checked all vacuum hoses. It has been doing this for a while now before I did the vacuum delete.
** power balance test while hot was hard as the engine is running rough and it was hard to tell the difference. I experienced drop over all cyllinders but was hard to estimate how much drop compared to others.
Rob is definitely right about replacing the det sensor being a lot of work. If your playing around with boost levels you definitely want it on there though. I had the same issue and relocated it to the top of the plenum. There are a bunch of guides around if you look and it's a bit of a compromise but I haven't had any issues. Where are you getting the boost reading from? Is it from the boost controller or the stock gauge? Are they saying the same thing?
Yes before doing the head gasket it was *okay*. So really could be anything. Something to note - removing the AAC connector does not change idle speed. I’m thinking that this wiring harness also needs replacing. Reading is from boost controller - stock gague doesn’t work. Got it not working unfortunately.
AAC values can be checked with a laptop and appropriate software, or with an ECUtalk unit. How did you determine that the knock sensor was faulty and determine oxygen sensor readings if you do not have diagnostic software?
First thing to do is resolve the det sensor code, (I believe?) this will cause the ecu to limit boost. Either use a resistor (search or buy Rob's kit) or bolt det sensor on the back corner of the plenum and plug it in there (though as Rob points out this won't affectively detect knock, will only cancel out the det sensor code). Then buy or make a device to allow boost leak testing. Rob probably has one of these on his website also. As with all troubleshooting, one step at a time with the simplest things first.
Make sure you didn't swap the cam plug for the other one on the passenger side. I think it could be the det sensor plug. Hopefully someone that knows exactly which 2 plugs sometimes get mixed up sees this and confirms which ones. cheers Dave
Definitely don't be trying to increase the boost via EBC while you have a bunch of other issues going on. ~7 psi is what you should expect to get with stock setup in safe mode. An idle as rough as you describe suggests something significant is amiss. I always liked this article: http://twinturbo.net/nissan/300zx/f...aration-Prevents-Piss-Poor-Performancegt.html
Where the question was asked. "Was the vehicle running OK before you did any of the modifications?" You replied. "Yes before doing the head gasket it was *okay*." One would naturally think the issue/s you have now could be in some way be related to "doing the head gasket". What exactly do you mean by 'doing the head gasket'?
