my idle bounces from 1000 to 1500 in park (automatic) and neutral, but when I put the car in reverse, or drive the idle doesn't jump it stays steady. I'm not too sure but can a bad PCV valve cause this? I looked at the hose that was connected to the PCV valve and saw that it was almost pinched. I have a D15B motor and the car has been sitting for a while. thx for the help.

 

more stats on the car what have you done to it?

 

i have an intake on it, recently changed spark plugs, oil, oil filter, and coolant but the problem still occurred even before this. I just recently got this car so I haven't done anything to it other than add a catback, it has been sitting for about maybe a year. Is there anything else u need to know?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by byronl &raquo;</TD></TR><TR><TD CLASS="quote">i have an intake on it, recently changed spark plugs, oil, oil filter, and coolant but the problem still occurred even before this. I just recently got this car so I haven't done anything to it other than add a catback, it has been sitting for about maybe a year. Is there anything else u need to know?</TD></TR></TABLE>

Did you bleed the cooling system of air after you replaced the coolant? That's usually the cause of eratic idle going from 1000 to 1500 at idle. Also if the PCV hose is really pinched you would hear a clicking sound from the PCV itself.

 

yea i bled the cooling system and it still did the same thing even before i changed the cooling system. The PCV hose looks like it's pinched but I don't hear any clicking sound from the PCV.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by byronl &raquo;</TD></TR><TR><TD CLASS="quote">yea i bled the cooling system and it still did the same thing even before i changed the cooling system. The PCV hose looks like it's pinched but I don't hear any clicking sound from the PCV.</TD></TR></TABLE>

How did you bleed the system? I don't mean to sound like your incompetent but I know a lot of people who think they know how to bleed the system but don't. Tell me how you did it. Also the eratic idle does it happen when the engine is at normal temperture or when it's cold?

 

i turn the engine on and press the upper radiator hose in different places until i got all the bubbles out, revved the car a little bit, add more fluid and repeat it over again until I see no air bubbles. And it does this while the engine is at normal temperature

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by byronl &raquo;</TD></TR><TR><TD CLASS="quote">i turn the engine on and press the upper radiator hose in different places until i got all the bubbles out, revved the car a little bit, add more fluid and repeat it over again until I see no air bubbles. And it does this while the engine is at normal temperature</TD></TR></TABLE>

You're doing it wrong. Proper way is to remove the radiator cap and run the engine until the fan turns on. That way any bubbles inside the block will move out to the radiator and out to the atmosphere. I usual let the fan turn on at least twice before I close the radiator cap. That's to ensure all the bubbles are fully bleed from the system.

If that doesn't fix the problem pull the IACV from the intake manifold and clean the screen off with brake cleaner or fuel injection cleaner. Usually if the IACV is clogged it will cause the idle to be eratic. The IACV is a valve that has a black round cylinder attached to it. It is mounted to the intake manifold in the back with two bolts and wiring harness attached to it too.

 

Oh yeah, i forgot to mention that I do that with the radiator cap off. I'll take out the IACV and clean the screen off like u mentioned and see if that does the trick. Thanks for the help, appreciate it.

 

I have a similar problem. When I pinch my PCV hose it click once and does not do it again. Should it click lots or just once? Does it need to be replaced?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bond &raquo;</TD></TR><TR><TD CLASS="quote">I have a similar problem. When I pinch my PCV hose it click once and does not do it again. Should it click lots or just once? Does it need to be replaced?</TD></TR></TABLE>

it's suppose to constanly click, if it doesn't click at all it needs to be replaced.

 

If air was trapped in the coolant system, would it stay trapped for a long period of time? (like 6 months?) My friend has a 92 CX with a 94 B18B1 swap with the usual I/H/E for mods, and it does the same thing. I'm going to try bleeding the system, because he's cleaned the IACV and replaced the air temp sensor. He says when he unplugs the coolant temperature sensor on the head, the idle stops bouncing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CycloneBlue_1.6EL &raquo;</TD></TR><TR><TD CLASS="quote">If air was trapped in the coolant system, would it stay trapped for a long period of time? (like 6 months?) My friend has a 92 CX with a 94 B18B1 swap with the usual I/H/E for mods, and it does the same thing. I'm going to try bleeding the system, because he's cleaned the IACV and replaced the air temp sensor. He says when he unplugs the coolant temperature sensor on the head, the idle stops bouncing. </TD></TR></TABLE>

It can be anything, my friend's 91 ls engine use to bounce so many time til we did a compression test and found out his head gasket is going bad. It cause the engine to sip air from that leakage and enter into the coolant passages causing that eratic idle. No matter how many times I've bleed the system or adjusted the idle, the idle would constanly bounce from 1k to 2k rpm. Also I recommend you pressure flush the coolant system. If you don't use distill water like you're suppose to and use regular tap water, all those minerals in the tap water will form inside those cooling passages causing possible blockages for the air to stay in the block. This will cause you to run in circles trying to figure out what's the problem could be.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sleeperciv &raquo;</TD></TR><TR><TD CLASS="quote">

it's suppose to constanly click, if it doesn't click at all it needs to be replaced.</TD></TR></TABLE>

Just clicks once. My idle likes to bounce from 800 to 1000rpm when the needle is just past the C on the temp gauge and stops once it gets past that. Could replacing this fix that?