1992 Honda Civic Engine Revving?

1992 HONDA CIVIC
120,000 MILES • 4 CYL • FWD • MANUAL
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RELOADMYLOVE
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Hello, and first and foremost I'd like to thank you in advance for any help you can give me. I changed out my intake manifold for an aftermarket one today, and for whatever reason when I started my car, the engine would rev itself...it goes from about 1,000 to 1,500rpms, repeatedly and continues to do so unless you either shut the car off, or pull the connector to the sensor map assy. The new intake manifold does not have a place to put the EGR valve on, so I didnt know if this may have something to do with it? A buddy of mine said there may be a vacuum leak? I checked and put in new gaskets with liquid gasket as well between the throttle body and intake manifold, and the intake manifold and where it bolts on to the block. Any help would be greatly appreciated! Thanks again for your time!

Sincerely,

Ryan Sanderson
Aug 29, 2009 at 8:03 PM
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MMPRINCE4000
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Yes it sounds like a vacuum leak since the problem started after the intake manifold replacement.

The MAP sensor must be connected to manifold vacuum, and a non functioning EGR may cause an error code.

The job of the EGR valve is to lower combustion temperature to prevent formation of oxides of nitrogen.

Is this intake an aftermarket unit or a Honda part?

You need to fix this ASAP as a vacuum leak will cause the engine to run lean and possibly burn a piston.
Aug 30, 2009 at 9:01 AM
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RELOADMYLOVE
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Yes this is an aftermarket intake manifold made by OBX racing sports. The whole project was a hassle but now it is on and everything is hooked up. The EGR is plugged in, but there isnt a spot to bolt it back on to the new manifold. Does it sound like the leak would be in one of the smaller vacuum lines or a leak between the intake manifold itself and the motor? I won't run the car until I get it taken care of as I can afford to lean out a piston. Thank you for your time!
Aug 30, 2009 at 9:20 AM
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RELOADMYLOVE
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I just went out because I also needed to change out my exhaust bolts because there was an exhaust leak from before. At any rate, I started the car up, and it did the same thing that I described earlier, but when I hit the gas, the car died out and stalled...I don't know if this information helps any...again I appreciate your help!
Aug 30, 2009 at 1:37 PM
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MMPRINCE4000
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Re-check your install, look for any small vacuum hoses that are cracked, make sure the injectors are sealed properly.

Most shops have a smoke generator to aid in finding vacuum leaks, just take your time and inspect each hose and all bolts are tight.
Aug 31, 2009 at 8:21 AM