car idles crappier.. Please help!!

[speed_racerx]

i recently moved from houston to long beach about a month ago. since then the car has been acting funny. some examples would include:

1. rpm's rev( by itself) up to 1400 for 20secs then drops to 8-900 for 10secs(shakes like hell when it revs that low) and repeats.
*problem was recently fixed when i regapped my sparkplugs

2. car still shakes like hell when it stays idle at 900 rpm's

3. my fuel economy dropped back to hummer h2 equivilent(spl?)
? im thinking that the culprit might be the octane rating difference between houston and long beach causing my knock sensor to activate. thats what i think but im no mechanic.:smash:

the motor is a S13 SR-Blacktop. the setup is fairly stock with smic, etc. if anyone is wondering, the octane rating in houston is 93.

thank you for all your help

anthony

[Wei240]

check ecu for codes, (which i don't think you can because s13 blacktops dont have led on the ecu??, not sure)

if not, get fsm (or search) and test your maf, mine did the exact same thing
and tps could be bad too..

[arminder_d]

93 is enough for an SR to run without detonation. I run 91 in vancouver bc and it does fine. I doubt your knock sensor is doing it. Check the wiring to your MAF and related sensors. Could just be tricking the ecu into think its getting a lot more air than it is.

[speed_racerx]

im not sure on how to check teh wiring or what to check for. its also feeling kinda laggy to me. i dunno... i was kinda leaning towards my timing. it did the same thing when my timing was off when i was back in houston.

what do guys set your timing to here in california? the second mark on the right, right? i was wondering if anyone could be so kind to help me check my timing and borrow teh timing light.

thank you for your help wei240 and arminder d

anthony

['90RPS13]

I have the same problem cept with my KAE. Just pulling home 20 minutes ago, it revv'ed its highest its ever done to 3,100rpm. Any help guys? *a

[Wei240]

could be timing, could be bad grounds (go to home depot and get fat gauge wires and go crazy)

for sr fsm, www.zeroyon.com thank them for putting fsm up, really helped me out alot

as far as KAE, go to www.240sx.org, there's a nice FAQ link for a lot of KA stuff...

[dvdevo]

make sure your gaskets are not leaking. More specificly the intake manifold gasket, spray some carb cleaner around that area.

[crazyikimasho]

...also check your IACV and clean it as well

[s13coupedrfter]

...also check your IACV and clean it as well

I cleaned the iacv on my single cam ka and it helped alot with stabilizing my idle. The sr20 is going to be much more difficult to get to the iacv though. As far as the fuel economy, could be your 02 sensor going bad. If your car shakes alot at idle check your motor mounts, s13 factory mounts are junk.

[arminder_d]

I think the kind of shaking hes getting is liek borderline stalling shaking. I reccoment you also check and see if any vaccuum lines may be disconnected!!!

[redsuns3838]

yeah the first two def sound liek vac line leak...
i know, because i have that problem. does it pause at like 1400when u disengage the clutch like when u come to a stoplight, then drop down to 800 when you actually stop?
mine does that. i just put a fmic on so it could be a leak or my bov.. you could go make a DIY vac leak checker from home depot...

ive also had a bad IACV that gave similar symptoms. i cleaned it out real good, that fixed it (different occasion tho)

if ur knock sensor was active it would really retard your timing and you would probly know it...plus the ECU would throw a code/ CEL would come on probly.

i cant imagine just using 91 would do that. everyones gets a good 20-30MPG off 91 from what i know and im in CA too..

check vac lines, aicv, ECU codes, then move on from there if it doesnt fix it.

[speed_racerx]

thanks guys!! i'll go tinker around with the car when i have some free time sometime this weekend. im swamped with homework and reading and crap....

AGAIN.. THANK YOU GUYS FOR ALL YOUR HELP!!

[speed_racerx]

dammit!!! my ecu doesnt have a led light on it...

problem with the link you sent me wei240... i keep on getting
" This Account Has Been Suspended
Please contact the billing/support department as soon as possible. "