Honda CRX Idle Surge

Avatar
GEEPSON
  • MEMBER
  • 2 POSTS
my crx revs up and down between 900rpm and 2300rpm , thought this was the map sensor , changed it twice and no difference . but when you dissconect the vacume pipe from the map sensor , or the manifoild end the car will idle perfect . but will only run for about 20 second s then the engine check light comes on and the car stops running . need help :(
Aug 15, 2006 at 7:18 AM
Advertisement
Avatar
BRUCE HUNT
  • ✓Experienced Mechanic
  • 3,754 POSTS
Sounds like a surging problem. Does this occur all of the time or only when cold and stop when warm? Have you had any other work done fairly recently to the car? IE - have you had someone work on the intake manifold? Had a coolant change?
Aug 22, 2006 at 2:30 AM
Avatar
GEEPSON
  • MEMBER
  • 2 POSTS
[quote:2691f1f7f1="Bruce Hunt"]Sounds like a surging problem. Does this occur all of the time or only when cold and stop when warm? Have you had any other work done fairly recently to the car? IE - have you had someone work on the intake manifold? Had a coolant change?[/quote:2691f1f7f1] ash - reply -
this deff isnt a surging prob . this occurs all the time, from engine ignition , untill switch off . could it possibly be a the engine not creating enough pressure or sorry vacume for the m.a.p sensor to read it . and could lack of vacume be a result of casket probs or worn rings . as i said i can stop this by taking off the vacume pipe that runs to the m.a.p sensor but the car will only run for so long until the management light comes on and car dies out . the m.a.p. sensor is deff not faulty as i have changed it three times . there musnt be enough vacume from the intake manifold . but the car runs good on acceleration and so on . what you think , personally i am baffled .
Aug 22, 2006 at 8:27 AM
Avatar
BRUCE HUNT
  • ✓Experienced Mechanic
  • 3,754 POSTS
Have experienced a similar problem and I would point to the intake gasket as a possible problem. Why is simple. The computer tries to adjust the fuel to the air is assumes is going to mix with the fuel but with the bad and leaking gasket there is extra air combining with fuel. So the computer dumps extra gas in. It is a match game that doesn't work and the car seems to rev and decelerate but down the road it seems to run pretty good. However, that is not really true. Take a check of that. The reaction of disabling the map sensor is exactly what should happen.
Aug 23, 2006 at 3:47 AM

Suggested Repair

Inspect the intake manifold gasket for a leak. Unmetered air can make the computer add extra fuel and cause the idle to surge; the MAP sensor reaction described is expected if that sensor is disconnected.

Conversation Summary

A Honda CRX SiR VTEC surges between about 900 and 2300 rpm whenever it is running. Replacing the MAP sensor several times did not help. Disconnecting the MAP vacuum hose lets it idle briefly, then the check engine light comes on and the engine dies. The owner suspected low manifold vacuum from a gasket or worn rings. The expert identified an intake gasket leak as a likely cause of extra air and unstable idle.

Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Frequently Asked Problems for This Vehicle