# my car idles extremely low.. and bogs down..



## xnxbladexnx (Aug 22, 2005)

ok.. i have a 1989 nissan 240sx auto... i bought a little over a month ago... im haveing a real hard time keeping i running when i am at stop signs or lights... the idle is very low.. to the point where it sometimes stalls out.... and tonight when i left from work... it barely stayed running and it was shakeing very badly..... so reved it up...and it barely reved.. it like just gave out.... so i put it in reverse to drive it home... and it barely moved.... then i put continued home and the pickup is horrible and its idle is very rough... any help plz... i would greatly appreciate it.......... i have also put new sparkplugs and wires.. distributor cap.. rotor... air filter... fuel filter... ..ive been reading up on this.. and from what i see... maybe the pcv valve isnt working?.. or fuel pump... or something along thoses lines... thnx....


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## Panda Rox Ur Face (Dec 19, 2004)

xnxbladexnx said:


> ok.. i have a 1989 nissan 240sx auto... i bought a little over a month ago... im haveing a real hard time keeping i running when i am at stop signs or lights... the idle is very low.. to the point where it sometimes stalls out.... and tonight when i left from work... it barely stayed running and it was shakeing very badly..... so reved it up...and it barely reved.. it like just gave out.... so i put it in reverse to drive it home... and it barely moved.... then i put continued home and the pickup is horrible and its idle is very rough... any help plz... i would greatly appreciate it.......... i have also put new sparkplugs and wires.. distributor cap.. rotor... air filter... fuel filter... ..ive been reading up on this.. and from what i see... maybe the pcv valve isnt working?.. or fuel pump... or something along thoses lines... thnx....



Is the Air Conditioning running? Do your lights dim out at any time, when idling, braking, accelerating? 

Have you checked your fuel pump? Make sure you check your fuel pressure. Should be at about 31 psi at idle. I seem to find these things going out ALL the time. Low fuel pressure will give you bad acceleration because you can't get enough fuel in the cylinders. May even cause a bad idle if fuel pressure is low enough.

Just make notes to yourself when it is happening. Try to notice other things when it happens. Respond back with some feedback at let us know, the more info you can give, the better we can help you.


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## xnxbladexnx (Aug 22, 2005)

my ac is off.... when i hit the brakes in any gear the clock light in the cluster goes dim for a sec...im working on checking the fuel pump... when i get time off work.... ive also been told the brake booster or somehting like that.. but idk.....ill get all the exact infor for u guys 2marrow.. thanx...


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## splavin90 (Aug 22, 2005)

sounds like the fuel pump.
the brake booster would make the car act like that.
when ever the brake booster has gone out on me, the brakes will lock up, and you'll be like WTF!?!?!
anyways, i hope you get your car back up and running.
peace.


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## xnxbladexnx (Aug 22, 2005)

ok... its not the fuel pump... cause i put a new one in today.... its running very bad... i took it to autozone.. they seem to think it is the throttle position sensor...
soooo im picking that up 2marrow... hoperfully it work...


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## ALSET (Aug 18, 2005)

IF YOU HAVE A SERVICE MANUAL , CHECK YOUR AIR MASS SENSOR, YOU CAN ALSO CHECK YOUR TPS BEFORE YOU GO BUY ONE, NO NEED TO BUY PARTS YOU DONT NEED


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## BlandAnalogy (Jul 19, 2005)

Yea those all could be areas for concern. yet the problem seems a bit more simple. you might wanna check you idle air control (IAC). at the same time you might want to adjust your idle and timing. keep in mind that being an automatic you should be idling at 800-1000 rpm while with a manual transmission you should be a bit lower than that. it could be fuel but the possibilities of that are more slim compared to the things i explained. at the same time you might wanna check mixtures out. stoichiometric which is basicly the "Ideal Air Fuel Mixture." at the same time should be 14.7:1. most people believe that fuel tuning is better for tuning at 13.7:1 but leaner mixtures arent always better. anyways sorry to ramble. id just start checking out the whole system.


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## xnxbladexnx (Aug 22, 2005)

ok now its not the throttle posistion sensor... so i took it back... now the car barely turns over.... and its definatly not driveable... plz help......


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## Zen31ZR (Mar 24, 2004)

Cam timing might be off, ignition timing might be off, massive vacuum leak, stuck-open EGR. Hard to turn over, check your battery as well. 12.6 volts without the key being on is what it should be.


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## xnxbladexnx (Aug 22, 2005)

hhmmm well... i just talked to my friend who is a mechanic.... he seems to think i blew a ring.... fuck........ if it comes to that i think ill be selling it...


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## ALSET (Aug 18, 2005)

HAVE YOU PULLED YOUR DIPSTICK AND CHECKED FOR WATER IN THE OIL?

AND THIS MECHANIC DIDNT HAPPEN TO KNOW SOMEONE WHO WOULD TAKE IT OFF YOUR HANDS DID HE?

JUST THOUGHT OF SOMETHING...JUST FOR KICKS CHECK YOUR AIR INTAKE BOOT FOR CRACKS, OR POSSIBLY CAME LOSE


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## Panda Rox Ur Face (Dec 19, 2004)

double post, sorry


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## Panda Rox Ur Face (Dec 19, 2004)

xnxbladexnx said:


> ok now its not the throttle posistion sensor... so i took it back... now the car barely turns over.... and its definatly not driveable... plz help......


Your mechanic thinks its the rings?

Well, try doing a dry compression test

Then try a wet compression test

A low compression can be caused by; bad rings, valves not seating, blown head gasket

For a head gasket leak; check for water in the oil, or when doing a compression test, check for air bubbles in the coolant. Also when compression testing, see if two cylinders that are right next to each other have low compression, this can be caused by a head gasket blown between these two cylinders.

If you have low compression on a cylinder(s), then doing a wet compression test will let you know if your rings are bad, or if it is just your valves. If your compression goes back up, then you know for sure that is rings, because the oil will seal the rings. If compression is still bad, then your valves are burnt, cracked, bent.

Your Mechanic should know how to do these tests, if not, Time to get a new one! ! !


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## xnxbladexnx (Aug 22, 2005)

ALSET said:


> HAVE YOU PULLED YOUR DIPSTICK AND CHECKED FOR WATER IN THE OIL?
> 
> AND THIS MECHANIC DIDNT HAPPEN TO KNOW SOMEONE WHO WOULD TAKE IT OFF YOUR HANDS DID HE?
> 
> JUST THOUGHT OF SOMETHING...JUST FOR KICKS CHECK YOUR AIR INTAKE BOOT FOR CRACKS, OR POSSIBLY CAME LOSE


...ok i found something that seemed to have broke off... its a hose that comes off the air intake box... and into yet another snaller baox... then into the headers..... what is that part called???


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## xnxbladexnx (Aug 22, 2005)

ok guys i found the problem ... it was pretty simple...
one of my fuel injectors were clogged... so i might have to get a new one... but its running fine now.... i had my neighbor come down and look at it today..... and her reved it up really high.... and it seemed to clear it out soo... thanx for all you guys's help...


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## Jordy240 (Jul 18, 2005)

Glad you figured it out there man. That hose your asking about is part of the emissions control system. it takes O2 out of your exahust and runns it througha filter and then back through your air intake before the Mas Air Sensor. That should cause much difference without it. When I installed my K&N cold air, I didnt reconnect it and it ran fine. I then reconnected it and it didnt change anything. Still its always better to have everything connected though. Its their for a reason, though it may be strange one, who knows. Keep on driving man.


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## dead1486 (Aug 25, 2005)

ya i had the same problem, TWICE! Damn those 240SX fuel injectors!


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## Hydrolock (Feb 18, 2005)

See if you can clear up the injectors with an injector cleaning service (not the stuff you pour in your gas tank) You need the set up to do it but any garage should be able to do it for you.


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