Hello every this is my fist post here so please bare with me. I have a 91 Honda si I find its will die sometime at a idle. Not all the time but just sometimes. This had been happening for a while now. I don't drive the car much anymore (not because of it). It starts fine idles fine runs good, but sometime when i come to a stop sign or when i get off the freeway the idle drops and dies. Then when I go to start it it wont start. But if I wait 10 mins it starts and everything is fine. I have read about the main relay switch and i live out here in calif and its not a weather thing. It does it when it's raining or sunny (when it does it). 2 years ago i had trouble smoging it, so I had a tuneup and oil change and it passes. Now 2 years later and only 25 miles more on it it passes. As i am talking to the smog guy how this car does this it does it again when he shut it off. After 5 mins it starts and all is good except that i don't know why its doing it. Thanks for any help upfront? Oh it passed smog no problems

 

Ok no reply so here is another question....I need a fuel pipe that goes from the fuel filter to the firewall. I looked everywhere so I need a used one. Thanks in advance

 

Things to look at:
-Vacuum leaks (intake gasket, hoses, brake booster, PCV valve): not enough vacuum will make the ECU do stupid things.
-Fast idle valve (back side of intake on driver's side): could be dirty or working intermittently
-idle valve (back side of intake with two heater hoses connected to the bottom): could be clogged with carbon, dirty. Does your idle fall off and then surge at idle repeatedly?

 

Thank you ChirsS, I fixed my fuel pipe problem and thought it was all good. I started the 91 civic si let it warm up then shut it off. I tried to start 5 mins later and all it would do is crank. I waited like 15 mins and tried it again and started right up. And the funny thing is it doesn't always happen.

 

Your current problem sounds like master relay has cold cracked soldered joints. My '91 crx si used to do the same thing until I resoldered all the connections in the master relay.
(if you don't know how to resolder, take the master relay to an electronics repair shop. It shouldn't cost much to resolder all the connections in the master relay.)
_or_
You could just replace your master relay (it's bolted under the dash behind the hood release near the driver's side door hinges)

take care,
ChrisS

 

Ok thanks I got the main relay out wow what a lil job that is. New should be here in a cpl days. Hope tix is the fix I need for this thing. Will keep you all updated

 

Ok got the new one installed it and haven't had the no start isue yet. Now I have noticed a few other things since I don't have o worry about it going to start. First is the muffler, and then it idles below 500 when warmed up. I think it used to idel around 900. It looks like it is going to die when I come to a corner but doesn't. Drives me crazy thinking its going to kill it self but goes down to like 250 then up to maybe 500.

 

Check the air filter. Replace if dirty.

There is an idle adjustment screw on the throttle body. Stand on the passenger side, look for a thin vacuum hose on the top of the throttle body coming toward you, the idle screw is brass and just to the left of where the vacuum hose attaches. (I think, I read somewhere that the idle speed should be 780 once warmed up.)

If the idle is constantly bouncing between 500 and 250, your Idle Air Control valve is probably gunked up with carbon. Use throttle cleaner to clean it. (one post I read said remove Idle Air Control valve from the car, pour throttle cleaner in each hole, and soak it for a few days. Cover the holes with your thumbs, shake it a while, pour out the dirty cleaner, repeat until no more carbon shows up in the cleaner.)

Look for vacuum leaks.

I'm currently having an intermittent stalling problem once the car gets to 1/3 normal operating temp until it has fully warmed up. (Adjusting idle higher fixed most of it. I'm probably going to remove the idle screw and clean it this weekend. More than likely there's carbon build up on it. It's a little tricky on my car because the idle screw is sticking/hard to turn and a previous owner did a major job on the slot in the idle screw; almost no grip for the screwdriver blade.)

take care,
ChrisS

 

So I adjust the brass slotted screw head like you said. Not sure but it's hangs around the middle between 250-1000. But I feel much better that it won't die now. And if it does I know it will restart. Now I am putting a radio back in it (someone broke into it and tried to steel it). I did replace all the exhaust from the CAT on back. And I am looking for the rear cargo cover dek lid. (also stolden)

 

Ok I got it running good now. Adjusted the idel up a lil. Got a new radio and cargo cover. Man my lil jelly bean is running so good right now. Thanks for all the help so far