Question about 1991 Honda Prelude
1991 prelude si... 2.1L...190k miles...the engine revs up and down while in neutral and in gear (manual trans).
Hey, first i would check all of your vacuum hoses. Over time they can crack and leak and that can create the problem, then the computer compensates to correct it. The throttle position sensor could also be a possibility and in combination with a vac leak, can create a wide variety of symptoms that are difficult to separate and trace down. Get a can of carb cleaner with the little spray straw, start the engine and let it idle to warm up. Spray a little on each vac connector, around the base of each injector or the throttle body, and see if the rpms run up. If so, you may have found a leak that needs tightening down. Vacuum hoses can sometimes just have the split end cut off and reconnected. The hard plastic spaghetti lines may be so brittle they need to be completely replaced. Manifold and throttle body bolts can be tightened up, but occasionally the gasket may need replacing. I would start with that and see what it does for you. Let me know if I can be of any more assistance.
Posted on Dec 08, 2008
a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
Tips for a great answer:
Mar 30, 2015 | 1991 Honda Prelude
Jan 23, 2010 | 1990 Honda Prelude
Nov 16, 2009 | 1991 Honda Prelude
Aug 06, 2009 | 1991 Honda Prelude
Apr 21, 2009 | 1999 Honda Accord
Jan 10, 2009 | 1998 Honda Prelude
Sep 16, 2008 | 1991 Honda Prelude
158 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: