surging idle problem

Post by **flames5351** » Tue Mar 21, 2006 10:33 am

ok i have searched this and can't find anything on my particular issue. When i start my car it idles fine but kind of high 2.4k. After a couple minutes when its warm the idle dies down to around 1.5k but bounces between 1.5k and 2k constantly. I can't seem to figure out why my car is doing this. Do i have a problem with vacuum leak or lines? or is my idle air control valve shot? its an s13 redtop in a 95 240sx fyi. any help or direction would be greatly appreciated, i would like to get this idle under control soon.

Post by **Neil** » Tue Mar 21, 2006 1:21 pm

could be throttle position sensor. mine did the same thing cuz it had water in it.

Post by **Silvia007** » Tue Mar 21, 2006 5:53 pm

Yep, not sure if it's normal but with SRtalk, it say's my TPS is at actually a little open even when it's completely closed. May just have to adjust it. Mines doing the exact same thing your's is doing but only from 800 rpm to 1500.

Post by **Neil** » Tue Mar 21, 2006 8:42 pm

SRtalk? Is that some kind of software?

Post by **flames5351** » Wed Mar 22, 2006 9:53 am

How do you adjust the tps? i have the s14 fsm because its the only one in english, i couldn't find anything in it on how to adjust tps. Well anyway with my car warmed up when i unplug the tps my idle jumps up to 3k and stays there steady. isn't the idle supposed to drop with the tps unplugged?

Post by **Neil** » Wed Mar 22, 2006 11:45 am

with the tps unplugged it should drop to around 700-800rpm but only when its warm and after you flick the throttle a few times.

there's a bunch of posts already on adjusting the tps. I know because I read one for myself when i first got my sr and have written up the instructions twice already for other ppl since

You need a multimeter and a paperclip. With the TPS plugged in, unbend the paperclip and stick it down into the plug boot next to the middle wire. (+) lead of the meter goes to the paperclip, (-) goes to ground or neg battery post. with the throttle plate closed it should read between .35 and .5 volts. To adjust the TPS its held in by 2 7mm/Phillips screws. loosen them, rotate the tps to .45v or so, snug them back down. If the reading bounces around at all the TPS may be water logged like mine used to be. If its letting thru too much voltage or not enough and adjusting it doesnt help enough, its probly just plain bad.

this is a very opportune time to check your ignition timing. please do a search if you're interested in doing this also.

Post by **flames5351** » Wed Mar 22, 2006 6:55 pm

ok ya sorry, i knew what the voltage should read and all that but i didn't realize you just had to turn it to adjust it. Timing is what i'm doing as soon as i get the idle under control thanks a bunch man

Post by **flames5351** » Thu Mar 23, 2006 4:10 pm

i did everything just like you said to but i never got any kind of reading, i tried several different times with both the car running and with just the ignition on. do i have a bad tps then?

Post by **flames5351** » Mon Mar 27, 2006 10:11 am

ok i'm frustrated. I replaced my tps and it still has the same problem. I still can't get a voltage reading from the tps output. I know i have it hooked up right its not that complicated. My idle is at like 3k with the tps unplugged. I tried to adjust the idle on the aicv and it did absolutely nothing, no response no matter how far i screwed it in. Also i checked continuity between the right terminal and ground and found there was no continuity. Does this mean my there is a problem in the wiring harness? Any help or suggestions are appreciated, I really need to get my car back and this is driving me nuts. thanks

Post by **Neil** » Mon Mar 27, 2006 9:40 pm

I don't know anything about the 'right terminal' of the iacv or what you check electrically to see if it's working. I wouldn't be quick to conclude a harness issue based on that one finding though. I have heard of them sticking open... but I don't know how to remove them either. Im sure I could figure it out if I had to... its just I haven't had the need to poke at mine yet.

As for the TPS you have to dig around down past the middle wire with the paperclip (or needle or whatever you use) to contact something metal down in the plug boot. You Are trying this with the tps connected, right?

Post by **johna_99_99** » Tue Mar 28, 2006 10:09 am

to get my idle down with tps unplugged i have to pinch that hose coming from the cold pipe going into the iacv............once i pinch the hose and idle drops....the idle stays down.......sometimes i have to do it a couple times....try that?

ya and like neil said shove your probe or paper clip right in there.......i dont even use a paper clip and i get a reading fine....just keep wiggling the probe until you see about 0.45V(with throttle released) on your multimeter

Post by **flames5351** » Tue Mar 28, 2006 10:42 am

ok i got a good reading and adjusting tps correctly. I didn't do anything differently except push harder on the ground to get the reading. on the iacv where do the two small hoses connect to? the mechanic who installed my motor didn't connect them to anything and i hope thats why my idle is jumping.

Post by **johna_99_99** » Tue Mar 28, 2006 10:55 am

you mean those 2 hoses?

Post by **flames5351** » Tue Mar 28, 2006 11:24 am

no not those, there are three total hook ups on the iacv. i know where the big one hooks up to but not the two small ones. I have a pic but it is over 500,000 bytes and i'm not that great at posting pics. i'll try to take a smaller pic or something later

Post by **johna_99_99** » Tue Mar 28, 2006 11:28 am

if you copy and paste it to the PAINT program and post it what hoses your talking about........i can just look on my car and tell you where they hook up.......i was looking at my iacv and not sure what hoses your talking about

Post by **flames5351** » Tue Mar 28, 2006 7:28 pm

there we go.... in yellow

Modified by flames5351 at 10:24 PM 3/28/2006
Modified by flames5351 at 10:26 PM 3/28/2006

Post by **discopotatoe** » Tue Mar 28, 2006 7:47 pm

you know i have the exact SAME problem as you...my idle is all whacky because my iacv valve is missing the bolt to adjust it..did you try playing with that....and in the pic above...you want to know where those to plugs go into that you circle??? lmk wana help

Post by **flames5351** » Tue Mar 28, 2006 8:19 pm

yes, I want to know what hoses are supposed to attach to the two inlets that are circled. Also I did try to adjust the screw with the tps unplugged and there was no change no matter how much i screwed it in and out.

Post by **johna_99_99** » Wed Mar 29, 2006 9:48 am

ok i tried to get the best pic possible..........each hose is only about 5 inches long......this is for the attachment(on iacv) that points out horizontally if it were installed

Post by **johna_99_99** » Wed Mar 29, 2006 9:57 am

this one is for the attachment(on iacv) that points straight down......where it attaches to is below the one in the first pic and it is a small diameter metal pipe(size of a pencil)

Post by **flames5351** » Wed Mar 29, 2006 10:01 am

thnks for the pics i'm gonna go check it out

Post by **flames5351** » Wed Mar 29, 2006 10:31 am

Where those both hook up on my car i have a hose that connects them together. I began removing the hose and coolant came out... does coolant flow through the iacv? upon inspection of the iacv the two small outlets looks like coolant flows through them because the outlets have coolant deposits on them. I just want to make sure the iacv does have coolant going through the 2 small hookups before i do this and send coolant somewere its not supposed to be and fry my iacv or something.

Post by **johna_99_99** » Wed Mar 29, 2006 10:50 am

im not sure

surging idle problem

surging idle problem

Re: surging idle problem (flames5351)

Re: (Silvia007)

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Re: (flames5351)

Re: (flames5351)

Re: (Neil)

Re: (flames5351)

Re: (johna_99_99)

Re: (flames5351)

Re: (johna_99_99)

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Re: (discopotatoe)

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