Really Bad Idle Help Please!!!
06-09-2006, 09:48 AM
#1
Really Bad Idle Help Please!!!
ya my car runs like crap. really rough idle. so rough that you have to keep foot on the gas for it not to die. it also is weak and kind of has the put-put sound from the exhaust. the injector was bad and i was getting a code, tested the resistance of all the injectors. front 3 were ok, so off went the intake plenum. middle rear one was bad. brand new from autozone and got a seal kit. it runs worse now than with the bad injector. not throwing any codes nemore. have to throw in neutral at stop signs and while braking. guy up at shop told me to spray carb cleaner around till it idles a little better with someone holding the throttle and then go from there. tried it to no avail. any more suggestions? might be along the same lines as his problem but far worse i guess.
06-09-2006, 11:52 AM
#4
yes its the same all the way around. ive done this twice. first time i thought it was because i used the original gasket, so i took the plenum off again and used new one. i also heard from guy at shop that something as simple as orings could be culprit. (they woudlnt even touch my car). im overlooking someting big here. to me it feels and sounds like a vacuum leak but i cant tell where the hell it would be coming from. i welded that stupid egr shut the second time around just cuz it wouldnt get back on without bending it.
so i know thats not the problem. cuz it acted the same before. im tempted to throw a vq motor in there but i have too many other projects and i have school and full time work. not to mention my 240z that im restoring (funny thing ive built the datsun from the ground up, and i cant figure out whats wrong with the max?)
update: i was also reading on here about faulty coolant temp sensors can cause similar problems but the car gets to operating temperature fine.
so i know thats not the problem. cuz it acted the same before. im tempted to throw a vq motor in there but i have too many other projects and i have school and full time work. not to mention my 240z that im restoring (funny thing ive built the datsun from the ground up, and i cant figure out whats wrong with the max?)
update: i was also reading on here about faulty coolant temp sensors can cause similar problems but the car gets to operating temperature fine.
06-09-2006, 12:16 PM
#5
Newbie - Just Registered
Join Date: Nov 2004
Posts: 4
Im having the same problem with my car. The first thing that happened was the check engine light came on so we took it in and they said a fuel injector so they fixed it and it ran good for about 1 1/2 weeks then it started doing it again. I think its another fuel injector but i dont no and i dont feel like dropping another $100 and that not be the problem do u think it could b anything else?
06-09-2006, 12:36 PM
#6
Senior Member
Join Date: Jul 2002
Location: Bellevue, WA
Posts: 702
I've been fighting a problem with a leaky injector and the biggest problem is that the fuel rail leaks down through it when the engine is off, flooding the cylinder and making it hard to start.
If your's isn't doing this, it starts fine and runs fine cold (if I understood properly) then it's related to the car warming up. Say a hose or gasket leaks when it warms or the coolant temp sensor.
Since you had to pull the plenum, did you get the several thousand vacuum and coolant hoses back where they belong?
If your's isn't doing this, it starts fine and runs fine cold (if I understood properly) then it's related to the car warming up. Say a hose or gasket leaks when it warms or the coolant temp sensor.
Since you had to pull the plenum, did you get the several thousand vacuum and coolant hoses back where they belong?
06-09-2006, 12:56 PM
#7
it doesnt start unless i put the pedal almost to the floor and i have to keep the pedal down while idling no matter how long its been running. im sorry if i wasnt clear. thats what i was thinking, i probobly havent hooked something up right. i hate newer cars and all their silly stuff they dont need lol. seems like when the brake is pressed, the engine revs are more sporaddic. thats what makes me think its a vaccuum leak. when the brake is not pressed i can keep the engine at a generally steady growl but when i have to brake is will all of the sudden shoot up above 3-4k even tho i have the same pressure applied to the gas as before.
06-09-2006, 01:47 PM
#8
Guest
Posts: n/a
Hey, sorry about your problem, but I think I may be able to help.
A while back my 2000 F-150 was having the same problem; rough starts, low/dying idle, etc. Turned out it was the "IAC Valve" (Idle Air Control) It limits the amount of air let into the intake, and if your IAC is damaged, dirty, or your sensor is not giving off a clear signal, it won't let enough air through to the engine, thus the engine trying to die. A quick search on this forum can give you a picture of where the IAC is, but I can tell you it's at the front right of the engine block just ahead of your airbox (closer to headlights) If you clean that, or replace it should fix your problem, although I have not had a problem with it on my Maxima after 11 years of ownership.
Another possible problem could be a dirty MAF (Mass Air Flow) sensor. This is located in the tube of your airbox. (Remove clips from airbox, look down tube, locate small silver object obstructing airflow in intake tube) If that's the case, buy some CRL ELECTRICAL CONTACT CLEANER (not carb cleaner) spray the living crap out of the silver box in the intake, then start up the car and give it some gas, if need be... have someone rev the engine in neutral while spraying.
Hope this helps, sorry for such a long post
A while back my 2000 F-150 was having the same problem; rough starts, low/dying idle, etc. Turned out it was the "IAC Valve" (Idle Air Control) It limits the amount of air let into the intake, and if your IAC is damaged, dirty, or your sensor is not giving off a clear signal, it won't let enough air through to the engine, thus the engine trying to die. A quick search on this forum can give you a picture of where the IAC is, but I can tell you it's at the front right of the engine block just ahead of your airbox (closer to headlights) If you clean that, or replace it should fix your problem, although I have not had a problem with it on my Maxima after 11 years of ownership.
Another possible problem could be a dirty MAF (Mass Air Flow) sensor. This is located in the tube of your airbox. (Remove clips from airbox, look down tube, locate small silver object obstructing airflow in intake tube) If that's the case, buy some CRL ELECTRICAL CONTACT CLEANER (not carb cleaner) spray the living crap out of the silver box in the intake, then start up the car and give it some gas, if need be... have someone rev the engine in neutral while spraying.
Hope this helps, sorry for such a long post
06-09-2006, 02:02 PM
#9
thanks man, ill have to fool with the IAC again. opening it up didnt do crap. i was trying to open it up to have it idle higher so it wouldnt die when i let off the gas, but turning it does not do anything. its kinda shoved down there but i think i might check it out. while im doing that, anyone have any more suggestions?
06-09-2006, 05:30 PM
#10
It is difficult to tell what it is just from your description. When my car had a bad coolant temp sensor, it ran like absolute hell, but it did throw a code for that.
If you are going to try the IACV, you need to take it off to clean it properly. Once you get it off, you will see why -- it has a bunch of turns that doesn't allow cleaner directly at the moving parts. You might as well take off and clean the TB why you are there. Get new gaskets for both.
Oh, do yourself a huge favor and make sure you have the gaskets IN YOUR HAND before removing IACV. I took off my IACV and TB, then called a half dozen stealerships before I got the gaskets sent to my local dealership from one in California. The car sat for several days while I waited for them.
My only other suggestion would be to find someone near you with a VE that you can try to swap out some things to see if it's the problem. Coil packs, MAF, cam position sensor would be some easy candidates to start with.
When mine had the stalling/bucking problem I swapped in about every possible sensor and finally got new coil packs (which solved the problem). Coil packs are tricky because they can test fine, but fail under load.
Good luck
If you are going to try the IACV, you need to take it off to clean it properly. Once you get it off, you will see why -- it has a bunch of turns that doesn't allow cleaner directly at the moving parts. You might as well take off and clean the TB why you are there. Get new gaskets for both.
Oh, do yourself a huge favor and make sure you have the gaskets IN YOUR HAND before removing IACV. I took off my IACV and TB, then called a half dozen stealerships before I got the gaskets sent to my local dealership from one in California. The car sat for several days while I waited for them.
My only other suggestion would be to find someone near you with a VE that you can try to swap out some things to see if it's the problem. Coil packs, MAF, cam position sensor would be some easy candidates to start with.
When mine had the stalling/bucking problem I swapped in about every possible sensor and finally got new coil packs (which solved the problem). Coil packs are tricky because they can test fine, but fail under load.
Good luck
06-10-2006, 05:22 AM
#11
if you tried turning th idle screw with no results iacv def. needs to be taken of and cleaned. i think it is only part of the problem but will help alot. does the car idle higher when first started? as said before the cts could also be bad. just because you get up to operating temp doesn't mean cts is ok. oh also you don't have to take off the intake plenum to resistance test the back three injectors. there is an injector subharness on the opposite side of plenum from the throttle body. the fsm shows which terminals to check for each injector.
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