Mechanical Problems & Technical Chat - won't start in warm weather

I've been trying to help a friend get his Honda back in complete working order, but I'm stumped on this one.... it's a '91 civic EX, with about 180K miles.... it works great, when it starts! Anytime the temp outsideis above about 70, it won't start. If he leaves it sitting overnight, giving it at least 4-5 hours to "cool down" it's fine.

SO?! What does this mean (aside from the fact that it's time to upgrade to a new Honda?)

this means its not a honda cuz "car always start!"


syke umm...so is is the weather that needs to cool down or the engine??

Main Relay. There have been multiple people with this same problem. all have been which of that the main relay. Located under the driver side kick panel. Big grey fuse, with a brown plug thing. Says "Mitsuba" on it.

winner

you guys are great, i'll check it out!

ok, since a certain auto parts store that shall remain nameless, sucks, we got the wrong relay! UGH! I went back in 3 times, and they kept messing me up! Anyway, I decided to go to a different parts store, but it was pretty late at night and everything was closed. We only removed the relay once, and put it back on immediately.....

This morning, the car started (it was only 50 degrees out).. but about 2 miles down the road it died! Apparently when the gas peddle was depressed, nothing happened- car coasted to a stop and then died completely. Now it won't start at all.

This is still a main relay issue, isn't it? Probably the relay is so shot that the fuel pump isn't working now? Is the best thing to do, replace the Relay first, then if the problem still exists, look at the fuel pump itself?

that sounds like a great idea...def. get the right relay

it could also be the distributor mycar did the same thing until i got a new one. the coil and ignitors are know to go bad. the coil controls the spark and fuel pump also.

ok, you all rock! it was totally just the main relay!but, now, new project!

I think we need to replace the dimmer switch? the instrument panel won't light up consistently, and from what i'm gathering the dimmer seems to be the issue? Can you confirm this? and if it is, can you tell me what i need to do to fix/replace it? Thanks!

buy a new dimmer switch it just unplugs then when u get a new one you can just plug that one in.

glad to help out man..... i wish mine was that easy. lol, i had my whole dash 2 bolts from comming out. I got a new relay switched, nothing.... electrical stuff sucks.

Im pretty sure that relay controls more than we can see. Like the pump, some ignition stuff... i know a wire goes from it to the fuse panel underneath the hood and one underneath the dash. Fuse #31 i think the ECU fuse underneath the hood and #14? under the dash... the starter switch or something.

Also with the dimmer switch, id just go to the junkyard and get one...

would the dimmer switch also be the reason that the cruise control doesn't work? Even if the cruise control is part of the steering column, rather than the switch? Or is that only the case when the cruise control switch is on the panel with the dimmer?

i'm sorry i'm asking so many questions, but you guys have been great!

i dont see why the dimmer switch wouldnt make your CC not work. Then again, electrical stuff can be all jacked up... Im not real sure if theres some wires going through where the dimmer switch go and the CC to its big box thing under the hood. I would check some fuses first and foremost. let us know if you got any more info.

There are several parts involved in the cruise control so it's going to get expensive to just start replacing without a proper diagnosis first. The major parts are the actuator under the hood (make sure the cable is actually hooked up to the throttle), a control box under the dash, and some switches. Besides the buttons on the column it is also interlocked with switches on the brake and (if manual) clutch pedals. When you press either pedal the cruise will drop out, if it thinks either pedal is pressed it won't engage. I think if it is a problem with the column buttons you have to replace the entire mondo lights/ dimmer/ turn signal/ wiper/ cruise combination switch assembly.