'93 Honda LX
#1
06-24-2009 | 10:22 AM
Unregistered
Posts: n/a
'93 Honda LX
I am on vacation for 2 weeks, and thought I would take care of some problems with my '93 Honda.
1. I had an accident and have to replace the front right light unit. I was going to replace yesterday, took most of the screws off, except for one bolt that sits in a very difficult place next the the bumper support. Do I have to take the bumper off to replace the headlight unit? The manual really doesn't address this.
2. I remember a thread last year about starting problems when it is hot outside, but I couldn't find it. I was trying to remember what the unit was that controlled this, but recall it seemed to be a common problem.
3. I have had an idle problem with the car in park - it goes between 1200 to 2500 or so as if someone is revving the car. What are some of the common causes of this?
Thanks. Every time I come here I learn something new.
1. I had an accident and have to replace the front right light unit. I was going to replace yesterday, took most of the screws off, except for one bolt that sits in a very difficult place next the the bumper support. Do I have to take the bumper off to replace the headlight unit? The manual really doesn't address this.
2. I remember a thread last year about starting problems when it is hot outside, but I couldn't find it. I was trying to remember what the unit was that controlled this, but recall it seemed to be a common problem.
3. I have had an idle problem with the car in park - it goes between 1200 to 2500 or so as if someone is revving the car. What are some of the common causes of this?
Thanks. Every time I come here I learn something new.
#2
06-24-2009 | 12:38 PM
Registered User
Joined: Jan 2007
Posts: 4,322
From: Brandon, MS
The answer to #2 is the main fuel relay. Do a search for "main relay" and you should find some good info. If you can't find what you need. Come back and ask.
As for #1 & #3, I'm not sure.
Try searching for "idle surge" or something like that.
I just searched and found a few posts. I plagiarized this from PAhonda in another thread:
Vacuum leak caused by low coolant, fast idle thermo valve (FITV), or the idle air control valve. There is a bleed bolt on top of the thermostat housing to let air out. Open that and the radiator cap. Allow coolant to flow until a steady stream comes out, then close that bleeder valve. Top of the radiator with coolant. The IAC has a screen that can get clogged with carbon that you can use throttle body cleaner on. You also might want to clean the throttle plate and bore to get rid of any buildup on there.
As for #1 & #3, I'm not sure.
Try searching for "idle surge" or something like that.
I just searched and found a few posts. I plagiarized this from PAhonda in another thread:
Vacuum leak caused by low coolant, fast idle thermo valve (FITV), or the idle air control valve. There is a bleed bolt on top of the thermostat housing to let air out. Open that and the radiator cap. Allow coolant to flow until a steady stream comes out, then close that bleeder valve. Top of the radiator with coolant. The IAC has a screen that can get clogged with carbon that you can use throttle body cleaner on. You also might want to clean the throttle plate and bore to get rid of any buildup on there.
Last edited by 00AccordLX5spd; 06-24-2009 at 05:56 PM.
#3
06-24-2009 | 04:24 PM
Junior Member
Joined: May 2008
Posts: 13
Interestingly, my '93 Accord has experienced the same problems you described. Here are what I know -
1. If you are replacing the whole front headlight unit (not the side marker), you will have to remove the 8-mm nut that holds the bumper to the frame.
2. Resoldering the main relay solved my problem.
3. I cleaned the IACV, FITV, TB plate & bore, EGR valves and ports w/ TB cleaner, and bled the coolant as described by 00AccordLX5spd. Spraying carb cleaner around hoses/gaskets appeared to find no leak. However, none of those cleaning have any effect in solving the idle revving problem so far. If you find a solution to this problem, please post.
1. If you are replacing the whole front headlight unit (not the side marker), you will have to remove the 8-mm nut that holds the bumper to the frame.
2. Resoldering the main relay solved my problem.
3. I cleaned the IACV, FITV, TB plate & bore, EGR valves and ports w/ TB cleaner, and bled the coolant as described by 00AccordLX5spd. Spraying carb cleaner around hoses/gaskets appeared to find no leak. However, none of those cleaning have any effect in solving the idle revving problem so far. If you find a solution to this problem, please post.
#5
06-24-2009 | 05:37 PM
Junior Member
Joined: May 2008
Posts: 13
One thing I notice is that this iidle revving problem occurs only when outside air temperature is above ~45 F. It never has problem during winter time. This makes me to believe that some kind of temperature-related expansion somewhere that causes this to occur only in warm day.
#6
06-24-2009 | 07:43 PM
Super Moderator
Joined: Sep 2006
Posts: 15,995
From: Houston, TX
For starters, clean the throttle body and throttle plate as best you can. Throttle body cleaner, an old tooth brush, and some rags will help you out a lot.
It sounds like one of the idle valves is messing up. Each valve allows air to bypass the throttle plate to regulate the amount of air entering your engine (idle).
The 93 is set up a bit different than my 95, so I attached a picture of your setup.
The three valves that are possible culprits:
8 -Fast idle thermo valve (FITV)
9 - Air boost valve
15 - Idle air control valve (EACV) aka IACV
In order to pinpoint which one is screwing up, you will need to block one at a time to find out which one is allowing too much air to enter the engine.
Remove black rubber intake duct from throttle body. Start engine and allow to warm up. Inside of the throttle body, there should be two holes in the bore (bypass for #8 and #15). Plug one at a time with your finger. Plugging one should cause your engine to stall (for #15). Plugging the other port (#8) will either do nothing, or stabilize your idle. If the idle stabilizes, then #8 is your problem.
To plug #9, pull off #22 from the intake duct. Pinch it off. If that causes the idle to stabilize, then #9 is the problem.
It sounds like one of the idle valves is messing up. Each valve allows air to bypass the throttle plate to regulate the amount of air entering your engine (idle).
The 93 is set up a bit different than my 95, so I attached a picture of your setup.
The three valves that are possible culprits:
8 -Fast idle thermo valve (FITV)
9 - Air boost valve
15 - Idle air control valve (EACV) aka IACV
In order to pinpoint which one is screwing up, you will need to block one at a time to find out which one is allowing too much air to enter the engine.
Remove black rubber intake duct from throttle body. Start engine and allow to warm up. Inside of the throttle body, there should be two holes in the bore (bypass for #8 and #15). Plug one at a time with your finger. Plugging one should cause your engine to stall (for #15). Plugging the other port (#8) will either do nothing, or stabilize your idle. If the idle stabilizes, then #8 is your problem.
To plug #9, pull off #22 from the intake duct. Pinch it off. If that causes the idle to stabilize, then #9 is the problem.
