messed up idle-any ideas? '91 FB

[Ghettokracker71]

I just bought an eBay CAI......don't flame me for "stupid purchase" or something...:nono: ....I pulled apart my intake,and the tubing doesn't fit...but the MAF adapter does,as does the filter and since my filter in the stock airbox was unbelieveably disgusting...:(...I knew I had to change it...so I put it on...and my idle is screwy....when I cold start it...it starts and runs like always..but...I don't understand because i have an inconsistant problem...Often when idling(park,drive and reverse have all had this)...sometimes sitting for a while,others just stopping at a light or the car has just warmed up...the idle will drop to about 500RPM's and violently dip into 350-ish range and jump back to 500 and systematically repeat...making a slight "bump bump bump" noise,my engine is otherwise 100% stock,...I am about to flip 107k....I know its a minor problem NOW...but I don't want to turn it into a HUGE probem later...Maybe I just need to reset my ECU?

[mistaanime]

hmm...i have something similar to the same problem..but it was becasue of mah throttle body..was dirty..and until i cleaned it..it ran great..but now..i dunno y it has been acting up..it goes bout 6 to 700 rpm while idlein...some people said.. i mite need a tune up..

[Ghettokracker71]

hmm...i have something similar to the same problem..but it was becasue of mah throttle body..was dirty..and until i cleaned it..it ran great..but now..i dunno y it has been acting up..it goes bout 6 to 700 rpm while idlein...some people said.. i mite need a tune up..
TB?...Hmm..I pulled off my intake tubing,and checked my TB and it was pretty damn clean,and I checked my MAF and it looked clean-ass too....tune-ups a good idea though...

[Ghettokracker71]

its getting worse and pissing me off damnit :(....anybody?

[pr240sx]

By any chance did you touch/move/bang the TPS?
Could be TPS sensor mis adjusted
Air leak ( most probable)

Did you try swapping everything back to stock?

[Ghettokracker71]

By any chance did you touch/move/bang the TPS?
Could be TPS sensor mis adjusted
Air leak ( most probable)

Did you try swapping everything back to stock?
hmm...good idea,I kind of don't want to b/c nasty ass purolater filter...honestly,its been soaked in like oil or shit,...I thought that and had a couple of people tell me it looks like it (??)

UPDATE:I tried resseting the ECU by disconnecting the batt for about an hour or so...and that definitely helped out ALOT...my dad says I should change the fuel filter and fog the intake(seafoam) and go from there....I need to to fuel filter anyway.....

TPS Sensor huh? how I do readjust this ? Should I leave this to a pro maybe...

[Ghettokracker71]

Okay...since my fuel filter is stock with 107k on it,I've decided to change it....I want to put the 300zx fuel filter in....what year 300zx should I get? Twin turbo or N/A ?

Thanks,....I searched but couldn't find it

[Ghettokracker71]

Since nobody has responded....and I am still having the problem,I am going to post an update...

First I saw that the MAF adapter was leaking,it wasn't square to the MAF and I could see into it,so I put bigger washers on it,and I tightened it down enough to all the edges and everything is flush then I replaced the fuel filter with a1991 300zx(I had them pull up every single Z fuel filter until I found the one that fit) brand new napa unit wich I couldn't really tell a difference,but considering the gas coming out of the old one that I pulled off was black,....its good that I changed it,I replaced the air filter with a different cone filter,and that made a nice difference but still not fixed....and I just got home from running seafoam,and it still does it :(:(

What should I do???????????? I've done everything my freinds/family have suggested,and now they are saying to take it to a mechanic.....anybody? PLEASE!

If nobody says anything I am taking her into a mechanic to have it fixed tomorrow...I am taking to Pence Nissan tomorrow for alignment anyway,but if I know I can fix it,then that'll save me $$


EDIT:ALso,I bought a new PCV valve....but I couldn't find it under my hood,....even while using my chiltons(don't flame,it has some good stuff and it was agift!)....I think once I take it into the mechanic I'll have them replace that too

[blackconvertible]

I feel your pain brother. I am having the exact same problem!

[pr240sx]

PCV valve

Good luck with that one,
The easiest way to change that is to remove one of the intake manifold bracket and remove the alternator (you can swing it away toward the outside)
Even in the FSM, the location for it isnt clear.
As for the TPS, is very easy to adjust, you will need:
A DVOM with aligator clips probes
2 metal neddles
Find the harness where the TPS connects to.
Insert one neddle at the back of the connector, be sure that the neddle touches the wire inside of the connector.
Put the other neddle on the other wire
The TPS receive 3 wires, one is ground, Middle one, another suplies 4 volts and the other is the signal wire. Thats the wire we are looking for. Once you have located that wire, use the DVOM to adjust the TPS. The ECU is looking for .50 +-2 volts for CLOSED throttle.
Adjust the signal voltage by twisting the TPS, you may need to loosen the TPS screws a little bit to do this.
Be sure to tighten them after finishing!!!

[Ghettokracker71]

PCV valve

Good luck with that one,
The easiest way to change that is to remove one of the intake manifold bracket and remove the alternator (you can swing it away toward the outside)
Even in the FSM, the location for it isnt clear.
As for the TPS, is very easy to adjust, you will need:
A DVOM with aligator clips probes
2 metal neddles
Find the harness where the TPS connects to.
Insert one neddle at the back of the connector, be sure that the neddle touches the wire inside of the connector.
Put the other neddle on the other wire
The TPS receive 3 wires, one is ground, Middle one, another suplies 4 volts and the other is the signal wire. Thats the wire we are looking for. Once you have located that wire, use the DVOM to adjust the TPS. The ECU is looking for .50 +-2 volts for CLOSED throttle.
Adjust the signal voltage by twisting the TPS, you may need to loosen the TPS screws a little bit to do this.
Be sure to tighten them after finishing!!!
Too late man ! Thanks for telling me that,its handy to know ....but I just got dropped off by the dealerships shuttle van.....

[mistaanime]

hheh all i did was adjusted the throttle body wire and know i do around 1100 to 1500 rpm at idle...well atleast you dun stall..hehit works and

[BEISSEN]

Try to reset the ecu check your connections on everything and you should be good be carefull about tighting the TB cable cus if you tighten to much you take a risk of snaping it then you will be SOL.

[Ghettokracker71]

Thanks for all the replies.....I replaced the MAF(80K on a super clean one...I cleaned whatever wasn't clean on it w/rubbing alcohol)....and it still had the problem....took it to a mechanic,they said I messed up the connector to the MAF, did something to it,and it ran fine for a while....I think I picked it up on tuesday,it was running great until yesterday...when it started to not idle right again....its definitely the same problem:(:(

On another note: My dash clock wouldn't fade out until my engine dropped to about 300 or below RPM's....now its fading when shes at a little above 500.....think that could be pointing to anything?

EDIT:Come to think of it....I've been having a really odd problem with my right blinker,during the day it works fine,but at night when I turn my lights on,the indicator lamp on my dash stays lit,and the blinker won't work? I don't think it could be related though....

This just really gets to me,b/c when I bought her,she was running perfect....:(

[240Driver39]

u made sure u put all the piping back on correctly, as to not have any vacuum leaks or such? simple...yet can cause u problems

[Ghettokracker71]

u made sure u put all the piping back on correctly, as to not have any vacuum leaks or such? simple...yet can cause u problems
Yeah,thanks for the suggestion!:)....Its electrical,I've determined it....I took out my subs,and turned my bass amp down all the way,and its been running fine since.....damnit:(:(:(:(:(

EDIT:The crazy thing is....it wouldn't idle right,when I didn't have my stereo on.....but its out,and when I listen to it,its just my stock replacement speakers with no other amp...its fine :ughd: