Hello, I'm new to this forum and new to my car as well. My car has been idling pretty bad for some time now and im not quite sure why. At first, the throttle cables were a bit loose, so I tightened them. The problem didn't go away so I checked my intake box (the good ol factory p.o.s.) and I found that my left intake isn't sucking in any air.
Like I said, I'm new to this car and I have a lot to learn about it and I would appreciate the help very much. Thanks for your time.
new car, lots of problems.
Re: new car, lots of problems.
hmm... that is odd. Confirm that the left throttle body is opening and closing as it is supposed to.
Re: new car, lots of problems.
Would I have to take off all the intake tubes?
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z32loverboy
- Posts: 516
- Joined: Tue Mar 22, 2011 6:05 pm
- Car: 1990 300zx CRP N/A 5 Speed (wreaked, now a shell) SOLD
1993 Slicktop CRP N/A 5 Speed w/ '90 built N/A motor and interior
1958 Ford f-100 straight-body (Grandaddies truck, resto-project) - Location: Nashville, TN
Re: new car, lots of problems.
Just the ones that connect directly to the throttle bodies. There's a hose clamp at each end that's an 8mm or flat head. Loosen both of them and pull em off, If you want to look at the throttle plates. It's a good idea to use carburetor cleaner to clean them if they're dirty. They stick sometimes if there's carbon/oil build up on them.
Re: new car, lots of problems.
Thanks for the help. I will get to work on them as soon as possible and come back to give some feedback. Im pretty sure I will run into more problems. Thanks again.
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DCaff300ZX
- Posts: 4202
- Joined: Sun Jun 14, 2009 8:18 am
- Car: .
1993 CRP TT- Modified - Location: Tacoma, Washington
Re: new car, lots of problems.
Be sure to check/tighten ALL of the hose clamps holding the intake tubes, as they may be loose as well causing a large vacuum leak.
Re: new car, lots of problems.
I checked all hose clamps and tightened them after checking if both throttle bodies open and close correctly. I found that my right throttle valve doesn't close correctly. I turned on the car and again it is idling at around 2k rpm. When I apply pressure to close the throttle body correctly, the rpms go down to about 1.5k rpms (which is what it was running right after I got it). If im right, a healthy engine should be running at around 1k rpms.
I have tried cleaning and rearranging the springs that hold the throttle bodies closed but that doesn't seem to work. I have also tried tightening and loosening the throttle cables but I get the same response.
Any ideas what I could do next?
I have tried cleaning and rearranging the springs that hold the throttle bodies closed but that doesn't seem to work. I have also tried tightening and loosening the throttle cables but I get the same response.
Any ideas what I could do next?
Re: new car, lots of problems.
There are lots of things that can cause the car to idle fast. The Z should idle at around 800 rpm when warmed up if all is well. Too high might indicate a problem.
You can check the engine codes to see if any codes are showing. Search here you should be able to find a link that tells you how and what the codes mean. Most of the time, if there is a code, it is because the sensor went out. Some sensor malfunctions will put the car into a limp mode so as to not damage the engine, this can cause the car to run very poorly. Anyway, check that, fix what ever it might indicate. If you have a question about what one of the codes means feel free to ask.
You should check to see if all your fuel injectors are firing. While the car is running, put the base of a long screw driver to your ear, and the other end to the top of each fuel injector. Be carefull not to get anything into the fan while the car is running like your hand or a tie. That could be very bad. You should be able to hear each fuel injector "click" as it fires. No click means that fuel injector isn't firing right.
You can also "ohm" them out by taking the fuel injector clips off and measuring the resistance across the injector. If one is out of specs (don't remember specs off hand, search google or site) you probably need to replace it.
As far as the throttle body, both sides should look nearly exactly the same as you pull on the throttle cable. The should open and close together and to the same degree of openness. You can adjust the throttle bodies if necessary.. search here or google for instructions. You probably shouldn't try to force the throttle body closed by pushing on the butterfly valve as you can bend it fairly easily.
You can check the engine codes to see if any codes are showing. Search here you should be able to find a link that tells you how and what the codes mean. Most of the time, if there is a code, it is because the sensor went out. Some sensor malfunctions will put the car into a limp mode so as to not damage the engine, this can cause the car to run very poorly. Anyway, check that, fix what ever it might indicate. If you have a question about what one of the codes means feel free to ask.
You should check to see if all your fuel injectors are firing. While the car is running, put the base of a long screw driver to your ear, and the other end to the top of each fuel injector. Be carefull not to get anything into the fan while the car is running like your hand or a tie. That could be very bad. You should be able to hear each fuel injector "click" as it fires. No click means that fuel injector isn't firing right.
You can also "ohm" them out by taking the fuel injector clips off and measuring the resistance across the injector. If one is out of specs (don't remember specs off hand, search google or site) you probably need to replace it.
As far as the throttle body, both sides should look nearly exactly the same as you pull on the throttle cable. The should open and close together and to the same degree of openness. You can adjust the throttle bodies if necessary.. search here or google for instructions. You probably shouldn't try to force the throttle body closed by pushing on the butterfly valve as you can bend it fairly easily.
Re: new car, lots of problems.
Also note there can be lots wrong with the car, and it won't have any codes. Again, most of those codes are for when a sensor isn't working. It can be running rich, lean, missing, etc., and the computer won't know.
Re: new car, lots of problems.
Throttle boy butterfly valve not closing completely (when not giving gas) will cause HIGH idle rpm due to extra air getting sucked in.
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DCaff300ZX
- Posts: 4202
- Joined: Sun Jun 14, 2009 8:18 am
- Car: .
1993 CRP TT- Modified - Location: Tacoma, Washington
Re: new car, lots of problems.
Hmmmm, now that's a new one...and you are correct in that the improper throttle butterfly needs fixing and could be your issue. There is a lot more to check out if fixing the linkage does not fix your idle problem, but the linkage does need to be correct to move on with your problem solving.
You need to check near the middle of the throttle linkage at the ends of the tension springs on both sides to make sure that the linkage isn't interfering with the little breather tubes that come out of your valve covers and are part of your PCV/idle circuit...the tubes can and will work themselves out and can cause issues with the throttle linkage. If one or both is lose and binding with the linkage, work them out carefully and clean them and the opening, and try using a tacky gasket glue or in my case I used a dab of epoxy I spread over the surfaces to glue them back in.
If this isn't the problem check that both linkage halves start and stop at the same point (there are stop "platforms" the linkages should bottom on) and if the linkage isn't bent, it may need to be adjusted or replaced if it has been removed.
Hope this helps, good luck and report back if you still have problems.
You need to check near the middle of the throttle linkage at the ends of the tension springs on both sides to make sure that the linkage isn't interfering with the little breather tubes that come out of your valve covers and are part of your PCV/idle circuit...the tubes can and will work themselves out and can cause issues with the throttle linkage. If one or both is lose and binding with the linkage, work them out carefully and clean them and the opening, and try using a tacky gasket glue or in my case I used a dab of epoxy I spread over the surfaces to glue them back in.
If this isn't the problem check that both linkage halves start and stop at the same point (there are stop "platforms" the linkages should bottom on) and if the linkage isn't bent, it may need to be adjusted or replaced if it has been removed.
Hope this helps, good luck and report back if you still have problems.