EGR issue

[suicide commando]

I actually found a diagram in the book that gave me an idea of where the connection was so I did a lot of feeling around and found it. I got the hose and ill throw it in tomorrow morning. Ill let everyone know how it works out

[fourdrinie]

[fourdrinie]

[suicide commando]

ok got the tube in and now the egr works properly. before i plugged in the hose i checked the egr diaphragm by pushing it in the plugging the vacuum line with my finger and it stays in until i remove my finger. now i have the hose in and the diaphragm pushes on its own when i give it gas. but the idle problem still exists. i took a short video of the idle stumbling a couple times. when i get over to the passengers side you can hear i little hissing. im not sure where thats coming from. all the hoses are fine and i cant pinpoint it.
video link: http://www.youtube.com/watch?v=tjAvNolgoZs

[yodawill2000]

Try spraying around with carb cleaner maybe ?
If its a VAC leak you should hear the RPM change when your near the leak.

[suicide commando]

Alright! Egr is working fine! The air leak was coming from the egr tube to the plenum. The gasket was too worn out. I just used some liquid gasket to sear her up and now it's idling fine. It passed smog today and I now have my plates on the car. Thanks to everyone for all the help

[fourdrinie]

Great news!

[yodawill2000]

Bravo !!

[suicide commando]

Alright finally got around to doing the knock relocation. Got a knock sensor from eBay. Also harness for 300zx from eBay. Got everything installed and the car has very slow response to the gas peddle. Checked for a code and got the egr code. For now I just threw the resistor back in and it runs perfect again.
Is it the knock sensor harness for the 300zx only has one wire on the side of the sensor and 2 wires on the side that goes to the ecu. Is this normal? Seemed weird to me when I first got it but looked up some pictures and saw some like that.

[suicide commando]

ok i looked it up and the harness is correct. 2 connections on the ecu side and one connection in the sensor side. either the sensor or the harness isnt working and i dont know how to test it. how do i test the harness when theres only one connection on one end?

[fourdrinie]

Check FSM page EC-196, it shows harness continuity checks and knock sensor resistance specs

[beaker.wright]

Hi, I'm new to the forum and the car. I have a 93 j30t that won't pass smog. It barely failed for HC, and was 700 out of 491 for Nox. I have no codes or check engine light.
Here is what I've done: checked all vacuum lines, tested the EGR with a vacuum pump, the valve moved up and the engine ran rough but didn't stall or really slow down much, so I removed and cleaned EGR valve and tubes (they were almost completely clean), tested solenoid with ignition on, it clicks and the flow through the valve is correct, plenum has good vacuum with 22" of mercury, but I heard a little hissing near the passenger side so I investigated with starting fluid and had no change in rpm. the car runs great, by the way, smooth and powerful. The exhaust does smell like an old car, though. I'm sort of out of ideas.

[fourdrinie]

Some people take the J30 for a really long drive to allow the cats to really get hot. How long did you run the car prior to testing?

[beaker.wright]

By the way, I did test warmed up cats. They were both about 340 degrees fareheit on the input side and 420 on the output side. I think that is good, i.e. heating up as they oxidize. Other than the exhaust being hotter leaving the cats, I don't know of any other test.

[beaker.wright]

I drove the car for about 40 minutes before the test, it failed with near identical numbers to the one prior to my work that I only drove about 5 minutes.

[fourdrinie]

Not sure where to go from here, but I would be interested in the outcome.
Just hope it you're not in CA, if it's your cats have failed...I had to replace mine and it wasn't cheap...definitely not worth the value for a 1993!

[beaker.wright]

Thanks, will post the outcome. Yes, I'm in California.

[fourdrinie]

Most gold star smog stations have diagnostic units to tell you which unit is failing, but they're not cheap!

[Mkiisupra]

Did you clean the egr tubes that run under the manifold or did you mistake the balance tubes on top of the manifold for them?

[GerryO]

These photos may help a bit. There are several short and long rubber hoses and tubing lengths between the EGR valve and the EGR control valve (located near the oil level dipstick).

Failing O2 sensors can cause the exhaust to smell bad. Mine wouldn't cause the CEL light to turn ON until slowing after extended highway drives.

[beaker.wright]

MKiisupra, thanks, yes I'm on to the right pipes. Easy to wish it was the top one...

GerryO, thanks for the pics. I'm on to the right pipes and have checked all vacuum lines. In your picture of the dirty manifold there are two approximately 1/2" by 12 rubber hoses that run fore and aft under the plenum, the big hoses in the first picture you posted above. Are those coolant lines? I think they are, which means they are not the source of the hissing.

Does anyone hear a hissing on the right front of the motor right around where the right hand throttle butterfly is?