My first post on Honda-Tech. I have a 96 lx sedan. I just replaced the head gasket and after doing so I start the car and the rpm's shot straight up to about 4k. After a couple of seconds they drop and then they go back up to around 3k then back down and it just keeps reving up, then back down, then up, then back down. I'm pretty sure it's a vacuum issue, I'm just not sure where. I was just wondering if anyone had a suggestions as to what might help me fix this.

Thanks in advance.

 

you have a sensor plugs mixed up They are on the intake manifold

 

Yea, sounds like you mxxed up the IAC sensor with something else, which isnt hard to do, the MAP, TPS, and/or IAC , they are 3-wire plugs. Plug them in their right sensors, reset the ECU, and you should be fine.

 

Thanks for the input guys.. I'm kinda new at this, so please forgive my ignorance. What does reseting the ecu intale? Do I just disconnect the battery or is it more than that? Thanks again.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by scald24 &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the input guys.. I'm kinda new at this, so please forgive my ignorance. What does reseting the ecu intale? Do I just disconnect the battery or is it more than that? Thanks again.</TD></TR></TABLE>

disconnect the battery for about 30 seconds, or you can pull the 7.5amp backup fuse under the hood for about 2 or 3 minutes

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by scald24 &raquo;</TD></TR><TR><TD CLASS="quote">Thanks for the input guys.. I'm kinda new at this, so please forgive my ignorance. What does reseting the ecu intale? Do I just disconnect the battery or is it more than that? Thanks again.</TD></TR></TABLE>

Nope, thats all, just disconnect it.

 

Yup, just disconnect the battery for less than a min, and ur fine, everything will go back to normal

 

Thanks alot guys. I think you saved me hella work. I was about to take the intake manifold back off and start checking hoses and stuff.

 

Alrighty.. Just got home and checked all the sensors on the manifold and they al seem to be plugged correctly. I reset the ECU and restarted it and rev'ed up to about 3k. Turned it off and back on and it started doing the same thing again. I'm going to take a picture and post it.. Any more ideas?

 

ok my friend had the same porblem and if it is not a sensor it may be possible a piece of the old intake mainfold gasket was still on there when you put the new one on. that is if you did change/ take off the intake manifold

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by h2point2 &raquo;</TD></TR><TR><TD CLASS="quote">ok my friend had the same porblem and if it is not a sensor it may be possible a piece of the old intake mainfold gasket was still on there when you put the new one on. that is if you did change/ take off the intake manifold</TD></TR></TABLE>


that and the sensors and also check your throttle body gasket if those dont work

 

Just did mine earlier this week, had the same problem. If you're revving to 3-4k it's a vacuum issue, most likely the intake manifold gasket or the intake manifold isn't tightened enough. I was missing a nut, put one on and it went right away.

 

make sure you have the right throttle body gasket. b16 and b18 are different. been ther e done that. mine idled the same way. has to be a vacuum leak.


Modified by jdmjeff at 8:37 AM 4/22/2007

 

It turned out it was the intake manifold gasket. I bought them off of ebay, like an idiot. Learned my lesson. Went to Advance and got a new one and that problem was solved. Now it starts and runs fine but it really lacks in the bottom end. Could that be my exhaust manifold gasket? Kinda sounds like I have an exhaust leak now. I'll be checking that later this week.

 

just check if the header is tightened down b4 checking the gasket... that or where it goes from 4-2 may be loose the exhaust flange from the 2-1 check everything before taking it apart