Honda Prelude Forum
Go Back   Honda Prelude Forum > Tech-Talk > General Tech Talk

Thread Title
89 prelude misfire and viberation

LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 01-30-2015, 01:39 PM
I'm New
Join Date: Jan 2015
Posts: 2
iTrader: (0)
medic387 is on a distinguished road
89 prelude misfire and viberation

Iv recently had an issue wich has me boggled. My 89 prelude b20a5 has a slight missfie at idle and viberation at driving rpm's. along with a ticking upon acceleration or when engine is pulling hills. I have replaced the air filter, plugs,wires,cap and rotor button, pcv valve, new timing belt, set the timing dead on, checked valve lash. Plugs appear to be burning clean,engine uses no oil , no smoke at all...However all efforts have improved nothing... Heres the catch it doesnt do this all the time just randomly. One day it runs superb with no ticking noise next day it may have the same symptoms. Then fine again on and on...I need help before sinking tons of $ over a simple fix.
Reply With Quote
  #2 (permalink)  
Old 05-12-2015, 10:53 AM
SpaghettiMonster's Avatar
I'm New
Join Date: May 2015
Posts: 12
iTrader: (0)
SpaghettiMonster is on a distinguished road
Re: 89 prelude misfire and viberation

It sounds like you're on the right track to sorting your issue, here.

Now... scary stuff - get it out of the way, 'cause it's cheap and easy to test. I highly recommend performing a warm engine compression test (wet rings), cold compression test (time for oil to drain from rings), and leak down test. You'll have to find the service manual for your specific model, for target values, but a good rule of thumb is 5-7% variance across cylinders is AOK. >10% = trouble brewing.

Per the work you've done, you can be fairly certain that your ignition system and intake side air handling are in good working order. The only other potential issues I can think of would be a goobered up MAP sensor or mis-gapped plugs (though both of these would typically be idle / low load issues)

Next thing to look at would be your fuel system. If you've got low fuel fuel pressure, especially at increased flow, you might start poorly atomizing fuel AND running lean. I would check / change fuel filters, and see if that helps. If filters don't solve it, check fuel pressure at idle (to test pump and FPR).

Once you confirm you've got the correct fuel pressure, try checking your injectors. You can do this by running for short periods of time on 3-cyl - pulling injector wires one at a time. (ideally, you'd just do this at idle, but it sounds like you'll need to put load on engine to diagnose). If the engine runs consistently on 3 cyl, the one you pulled is probably not the problem. If you run on 3, and intermittently on 2, then the injector you pulled is not on the problem cylinder.

There's more, but hopefully this should get the ball rolling again.
...Somewhere in Southern Indiana
- 1985 Prelude DX 5 Speed - Gothic Gray Metallic
- 2011 Subaru STi 5 Door - WRB
Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
misfire!!! UR_FUKED3_2 4th Gen Honda Prelude 9 05-08-2012 01:47 AM
My Prelude (Misfire) Diagnosis zadeh79 5th Gen Honda Prelude 1 01-12-2012 06:43 PM
help: misfire hall756 5th Gen Honda Prelude 18 05-01-2011 10:05 PM
misfire help tjsh22a4 5th Gen Honda Prelude 21 01-29-2011 04:08 AM
h22 misfire SpYd3r05 5th Gen Honda Prelude 6 05-11-2009 09:41 AM

All times are GMT -4. The time now is 05:35 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
LinkBacks Enabled by vBSEO 3.6.0 PL2 © 2011, Crawlability, Inc.

Copyright © 2006-2009 All Rights Reserved.