Idle and Drivability issues (i searched) - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

sileight_04 · 03-28-2008, 01:13 AM

Let me first start by apologizing if this is something that has been brought up before. I did use the search to the best of my search abilities and also have read a couple hundred pages into the tech section with no luck. =(

first off this is my 3rd 240sx, this one being a 93 KA24DE. I purchased it from the original owners. This is the only one that has had a KA in it for more than a few weeks, so my knowledge of the ka is not plentiful. The original owners did have the motor rebuilt a little over 10k ago with receipts.

Now on to the issue(s).
1. The car refuses to idle decently, seemed as if it was suffering from a dirty iac and was in need of a tune up and maybe a missfire. it fluctuates and like to stay about 1k for a while. it seems to also throw timing around a lot. I cleaned the Iac and replaced the plugs, wires, rotor and cap, as well as your other tune up items. It still idles terribly.

2. here is the part that i can't even begin to wrap my head around... It starts up and idles (bad, but it idles and drives) While driving or just free reving, it will just drop the revs and then try to go back up and then drop them again and so on and so on all while still having the throttle applied. this usually happens after driving the car around for 10-15 minutes and/or normally between 2k-5k rpm. It doesn't always happen in a certain amount of time but does every time the car is driven. it is bad enough to where it becomes un drivable. I have no idea what it could be, it didn't happen for the first day or two after the car was bought and the stuff listed above was done after it all started. I have thought of it maybe being off on ignition timing so i restabbed the distributor, still happens. checked to see if injectors are clicking away and when pulled create a stumble. has spark.

I am really at a loss of what to do, Ive read through the FSM rigorously with no positive outcome pertaining to this. I would greatly appreciate any and all help! if this has been brought up and you know where its at, point me in the right direction. Please help me out as best you guys can.

Thank you for your time,
Jonathan

sileight_04 · 03-30-2008, 01:56 AM

Anyone? Any suggestions or theory's at all? someone please help, I'm stumped.

s13drob · 03-30-2008, 02:11 AM

maybe a dirty/bad maf

playastarkz123 · 03-30-2008, 07:27 PM

^ beat me to it.

also try checking the wire connections to your maf, they maybe loose or just bad....I had a similar problem with my sr. I swapped out the maf for z32 one and the car idles and drives perfectly now

darkslide · 03-30-2008, 07:57 PM

how well did u clean out the iac?? kinda sounds like it has a tps problem, i had a veryyyy similar problem on my civic, it gave a tps code but ending up being the ecu that was bad.. GL =]

KA-T_240 · 03-30-2008, 08:07 PM

disconnect your maf, if it runs fine, then clean the maf.

Z U L8R · 03-30-2008, 08:45 PM

i also concur on the maf, that's where i would start as well.

other possible culprits could be leaky injector o-ring, tps, ignitor ie distributor itself. in that order i would test per fsm diagnostic to deduce driveability problem......or you could take your car and put it on our steady stay mustang dyno and we can check everything at any given rpm with the correct load on the vehicle to simulate it in actual driving conditions......then after we fix it we can run the 1/4 mile on it and get your actual time within xx.x_ ( +1/-1 a hundredth) of a second hahaha.

(sorry i'm psyched about our dyno we just got @@!! it's kick ass!)

Dave =]

silpena · 03-30-2008, 08:50 PM

ur dizzy may be off. I had the problem where it would flutter even after cleaning and replacing everything. Try re setting it to tdc and set the distributor at 1 and re time it. Can't hurt to try. My other guess could be a bad ground or tps.

sileight_04 · 03-30-2008, 11:44 PM

thanks everyone for the input, It is really appreciated! im going to check some of those things tomorrow and see what comes up. thanks again

cronux · 03-31-2008, 03:47 PM

oh, and this may be rediculous, but check to make sure your battery terminals are attached firmly. as if the positive is loose, it can lose connection, and cause a wierd crazy drop in rev's and then back up. just something else to check.

menace89 · 03-31-2008, 06:14 PM

ohh ohhh lol i got a 93 240sx and it starter happening about the idle shit...it took me 4 days 2 find out..and i finaly got it fixed...i dont noe if is the same on all cars....but ok here it comes...i hope this helps u....first i change my spark plugs...then my cap and rotor...then clean the MAF sensor...then the car was the same....i was getting pissed every sec...but wen i change the fuel filter the car got better...my idle was soo good in 2 days or 1 day...u noe u have 2 wait until your filter gets used 2 it and all that....just change the fuel filter and give it 1 day or drive it for 20 just 2 make the fuel filter get use 2 it.....aight...hit me back if u got any questions
Pz

grachman · 03-31-2008, 07:47 PM

If you still have the air injection valve, disconnect the rubber hose that goes from canister to fuel filter box. You can leave it that way with no problem. just plug the resulting hole in air filter box.

landins13 · 03-31-2008, 09:57 PM

if youre still having trouble. go here http://www.240edge.com/manuals/91-94_240sx/ec.pdf
start on page 33 of the section that comes up and work your way down, you should be able to narrow your problem down and fix it.

03-28-2008, 01:13 AM	#1
sileight_04 Zilvia Member Join Date: Jul 2004 Location: VA Posts: 181 Trader Rating: (0) Feedback Score: 0 reviews	Idle and Drivability issues (i searched) Let me first start by apologizing if this is something that has been brought up before. I did use the search to the best of my search abilities and also have read a couple hundred pages into the tech section with no luck. =( first off this is my 3rd 240sx, this one being a 93 KA24DE. I purchased it from the original owners. This is the only one that has had a KA in it for more than a few weeks, so my knowledge of the ka is not plentiful. The original owners did have the motor rebuilt a little over 10k ago with receipts. Now on to the issue(s). 1. The car refuses to idle decently, seemed as if it was suffering from a dirty iac and was in need of a tune up and maybe a missfire. it fluctuates and like to stay about 1k for a while. it seems to also throw timing around a lot. I cleaned the Iac and replaced the plugs, wires, rotor and cap, as well as your other tune up items. It still idles terribly. 2. here is the part that i can't even begin to wrap my head around... It starts up and idles (bad, but it idles and drives) While driving or just free reving, it will just drop the revs and then try to go back up and then drop them again and so on and so on all while still having the throttle applied. this usually happens after driving the car around for 10-15 minutes and/or normally between 2k-5k rpm. It doesn't always happen in a certain amount of time but does every time the car is driven. it is bad enough to where it becomes un drivable. I have no idea what it could be, it didn't happen for the first day or two after the car was bought and the stuff listed above was done after it all started. I have thought of it maybe being off on ignition timing so i restabbed the distributor, still happens. checked to see if injectors are clicking away and when pulled create a stumble. has spark. I am really at a loss of what to do, Ive read through the FSM rigorously with no positive outcome pertaining to this. I would greatly appreciate any and all help! if this has been brought up and you know where its at, point me in the right direction. Please help me out as best you guys can. Thank you for your time, Jonathan

03-30-2008, 08:07 PM	#6
KA-T_240 Nissanaholic! Join Date: Sep 2005 Location: Moorhead, MN Age: 38 Posts: 1,788 Trader Rating: (0) Feedback Score: 0 reviews	disconnect your maf, if it runs fine, then clean the maf. __________________

03-30-2008, 08:45 PM	#7
Z U L8R Zilvia FREAK! Join Date: Jan 2007 Location: Georgia Age: 43 Posts: 1,194 Trader Rating: (0) Feedback Score: 0 reviews	i also concur on the maf, that's where i would start as well. other possible culprits could be leaky injector o-ring, tps, ignitor ie distributor itself. in that order i would test per fsm diagnostic to deduce driveability problem......or you could take your car and put it on our steady stay mustang dyno and we can check everything at any given rpm with the correct load on the vehicle to simulate it in actual driving conditions......then after we fix it we can run the 1/4 mile on it and get your actual time within xx.x_ ( +1/-1 a hundredth) of a second hahaha. (sorry i'm psyched about our dyno we just got @@!! it's kick ass!) Dave =] __________________ RB25 280z GT30/76R 441hp/381tq 11.9@125

03-30-2008, 01:56 AM	#2
sileight_04 Zilvia Member Join Date: Jul 2004 Location: VA Posts: 181 Trader Rating: (0) Feedback Score: 0 reviews	Anyone? Any suggestions or theory's at all? someone please help, I'm stumped.

03-30-2008, 02:11 AM	#3
s13drob Zilvia Addict Join Date: Jan 2008 Location: socal Posts: 774 Trader Rating: (29) Feedback Score: 29 reviews	maybe a dirty/bad maf

03-30-2008, 07:27 PM	#4
playastarkz123 Zilvia Junkie Join Date: Apr 2007 Location: New Jersey Age: 35 Posts: 328 Trader Rating: (8) Feedback Score: 8 reviews	^ beat me to it. also try checking the wire connections to your maf, they maybe loose or just bad....I had a similar problem with my sr. I swapped out the maf for z32 one and the car idles and drives perfectly now

03-30-2008, 07:57 PM	#5
darkslide Leaky Injector Join Date: May 2007 Location: evergreen Posts: 72 Trader Rating: (1) Feedback Score: 1 reviews	how well did u clean out the iac?? kinda sounds like it has a tps problem, i had a veryyyy similar problem on my civic, it gave a tps code but ending up being the ecu that was bad.. GL =]

03-30-2008, 08:50 PM	#8
silpena Zilvia Addict Join Date: Jan 2008 Location: LIVE OAK,CA Age: 38 Posts: 834 Trader Rating: (2) Feedback Score: 2 reviews	ur dizzy may be off. I had the problem where it would flutter even after cleaning and replacing everything. Try re setting it to tdc and set the distributor at 1 and re time it. Can't hurt to try. My other guess could be a bad ground or tps.

03-30-2008, 11:44 PM	#9
sileight_04 Zilvia Member Join Date: Jul 2004 Location: VA Posts: 181 Trader Rating: (0) Feedback Score: 0 reviews	thanks everyone for the input, It is really appreciated! im going to check some of those things tomorrow and see what comes up. thanks again

03-31-2008, 03:47 PM	#10
cronux Zilvia Junkie Join Date: Oct 2006 Location: wI Posts: 300 Trader Rating: (0) Feedback Score: 0 reviews	oh, and this may be rediculous, but check to make sure your battery terminals are attached firmly. as if the positive is loose, it can lose connection, and cause a wierd crazy drop in rev's and then back up. just something else to check.

03-31-2008, 06:14 PM	#11
menace89 Join Date: Mar 2008 Location: VA Age: 35 Posts: 2 Trader Rating: (0) Feedback Score: 0 reviews	ohh ohhh lol i got a 93 240sx and it starter happening about the idle shit...it took me 4 days 2 find out..and i finaly got it fixed...i dont noe if is the same on all cars....but ok here it comes...i hope this helps u....first i change my spark plugs...then my cap and rotor...then clean the MAF sensor...then the car was the same....i was getting pissed every sec...but wen i change the fuel filter the car got better...my idle was soo good in 2 days or 1 day...u noe u have 2 wait until your filter gets used 2 it and all that....just change the fuel filter and give it 1 day or drive it for 20 just 2 make the fuel filter get use 2 it.....aight...hit me back if u got any questions Pz

03-31-2008, 07:47 PM	#12
grachman Join Date: May 2007 Location: canada Posts: 36 Trader Rating: (0) Feedback Score: 0 reviews	If you still have the air injection valve, disconnect the rubber hose that goes from canister to fuel filter box. You can leave it that way with no problem. just plug the resulting hole in air filter box.

03-31-2008, 09:57 PM	#13
landins13 Zilvia Addict Join Date: Jan 2008 Location: Baltimore Posts: 986 Trader Rating: (3) Feedback Score: 3 reviews	if youre still having trouble. go here http://www.240edge.com/manuals/91-94_240sx/ec.pdf start on page 33 of the section that comes up and work your way down, you should be able to narrow your problem down and fix it.