starts high rev then bog to quit

[hatersloveme]

i just got my 1992 nissan 240 running and i start it and unles you are messing with the throttle then it revs up to about 2000rpms then goes down to 400ish rpms then quits. im buying a egr block off plate will it help at all??? also where can i find a vacum hoses so i know what to take off. thanks

[seang]

What do you mean by "find" the vacuum hoses? Like new lengths of hose? the only way an ERG plate will fix it is if the EGR valve is to blame. I wonder if the Idle Air Control (IAC) valve is messing up.


Modified by seang at 1:55 AM 3/6/2010

[hatersloveme]

well i need to know where the vacum hoses go to. and i already took off the idle control and cleaned it. i got it to idle and stay running but it idles at 1300 rpms. i have adjusted the idle control valve because it was idleing past 2000 rpms. but the only thing i can think of to do is twist the distrubiter one way and see if that will help adjust the idle. first i need to make sure i have the vacum hoses in the right spot so i can tune it. also do you know if i have to have the throttle position sensor pluged in when i tune it? ive heard you dont need it plugged in, and is there anything else when it comes to tunning i have to do first??? thanks

[seang]

I'm going to go ahead and say that the throttle position sensor (TPS) should always be plugged in and set at the right spot.

Adjusting the distributor is not the right way to change the idle, it should be at least set to factory spec for now. I know my idle adjuster is right on my ECU and it can be turned with a small flathead screwdriver. My truck is also OBD2 and it's the Hitachi unit from a truck; so I don't know about yours, which is OBD1 and a JECS.

Vacuum diagram should be under the hood somewhere. If not, here is a downloadable factory service manual (FSM) for your car: http://www.nicoclub.com/FSM/240sx/91-94//

I'm not sure what to tell you next, because it sounds like you are pretty new at all this. Let me know how everything goes. I love seeing other Michigan owners on here

[hatersloveme]

i need a vacum hose diagram like a picture of where they go. because i have no idea where the go to.

[seang]

You have to navigate through the link I posted.

First, open the link.

Secondly, open or save the PDF link titled "EC.pdf"; this is for engine and emission control overall system. Pages 6 and 8 are vacuum diagrams.

[hatersloveme]

ye i got them printed out. thank you. i will try to put them together tomorrow.