280ZX Performance / Technical Discussions related to Turbo charging, Supercharging, Engine, ECU, exhaust, and etc. performance enhancements.
Sponsored by:
Sponsored by:

Rough Idle Problem

Thread Tools
 
Search this Thread
 
Old 05-28-2009, 05:37 AM
  #1  
Registered User
Thread Starter
 
stiletto660's Avatar
 
Join Date: Jul 2008
Location: Olathe, KS.
Posts: 61
Rough Idle Problem

Hi Guys & Gals,

I'm having a problem with a 1980 Non Turbo zx. I started off having a idle speed problem, it was idling way to fast after warmup around 1300 rpm, I started by changing all the vacuum hoses under the hood, replaced the air regulator, set the timing & TPS to spec according to the FSM. That didn't take care of the problem. Next after some additional trouble shooting I determined that the BCDD that is mounted to the lower portion of the throttle body was defective. I was lucky enough to find a new old stock OEM throttle body and installed it, and the fast idle problem went away. Now however I"m having a problem with rough idling. The car is hard starting in the morning but runs ok once it warms up. I suspected the fuel pump might not be delivering fuel to the system at the right pressure, and I can't here the fuel pump activate when I turn the key to the "ON" position like on all my other ZX's I'm a little confused about the fuel pump...... since it's electrical I thought that if the pump is not energizing that the car would not start at all? I am planning on putting 12 volts directly to the pump at the connector to see if I can here the pump running to determine if there is a problem in the electrical circuit or if it is the pump itself. Any other suggestions?
stiletto660 is offline  
Old 05-28-2009, 08:03 AM
  #2  
The Good Twin
 
NismoPick's Avatar
 
Join Date: Aug 2005
Location: Wild Wild West, UTAH!
Posts: 20,639
Have you already checked the fuel pressure? Fuel pressure regulator? Cold start valve?
NismoPick is offline  
Old 05-28-2009, 10:03 AM
  #3  
Registered User
Thread Starter
 
stiletto660's Avatar
 
Join Date: Jul 2008
Location: Olathe, KS.
Posts: 61
Rough Idle Problem

The cold start valve is operating fine, I don't have a fuel pressure gauge so I guess I will have to either borrow one or buy one. How do you test the pressure regulator? with a vacuum gauge? and what about the fuel pump
not energizing with the key in the "ON" Position? I have 3 other zx's and I can
here the fuel pump activate when I turn the key.

I appreciate your response.

Thanks,

Phil
stiletto660 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
MR2ZX
280ZX (S130) Forums
13
12-08-2015 08:31 AM
ryencoke
FS: 300ZX (90-96)
1
05-18-2012 11:45 AM
gammbinoZ
300ZX (Z32) Performance / Technical
3
04-03-2003 07:15 PM
John300
300ZX (Z31) Forums
1
12-02-2002 09:09 AM
jbaran1123
300ZX (Z32) Performance / Technical
1
09-11-2002 01:03 PM



Quick Reply: Rough Idle Problem



All times are GMT -7. The time now is 03:39 AM.