fuel relay/main relay

anyone knows what might be the problem?.... i have a 1993 honda prelude. i've been having problems with it for a year now or maybe longer. what its doing is that early in the morning it wouldnt start. it crank but wouldnt start. some morning it start up just fine, but lately i've been having problems like 2 to 3 times a week. some morning it starts up with no problem. some morning it just crank but wouldnt start. there's a time where i go back 5 minutes later it'll start up with no problems after i've been trying to get it started. my wifes honda accord starts to do the same thing. i dont have a clue what problems might be. though, some of my friends say its a main rely and some say its the starter. does anyone know what the problem might be? thank you for your time.

i had a problem with my 93 prelude a while back that it would not start after driving and it had to sit for about 5 mins. It turned out be my fuel relay under the dash. The tech explained to me when you turn the key into "on" position if there is a click from under the drivers side dashthe relay is working but if no click then problem with relay. Hope that helps.

these relays develope cold solder joints on its little circuit board. get a new relay, or do it the hard way and resolder the board. i also skeeted a little wd-40 in mine, what could it hurt, works good now. some of these relays will not pick up when the inside of the car is really hot. (these suckers are hard to get to)

check this link out. this should help. this prob has come up in the teg forum alot lately. http://www.g2ic.com/forums/showthread.php?s=&threadid=44386

i like to thank everyone so much for your reply. ya'll have been a great help. wish i ask you all first before i had my motor installed in my prelude si. couple of months ago my timming belt broke so i went a had and ask the shop to find me a new motor and have it install in my 92 honda prelude. when i went and pick up my prelude i was told they had put in a 96 integra vtec in my 92 honda prelude si. i thought since it's a 96 motor and a vtec and it's from Japan and that they said the millage on the motor is somewhere about 40,000 miles... i thought it's better or ok atleast. But now i was told by many of you that i would have been better off if i had kept the factory motor (original honda prelude si motor). the total for the motor and the labor was about $2,500.00. so anyways, because of ya'lls reply and advice i realize that i made a bad choice. well, i didnt know any better then. at that time i just wanted a new motor and to have my car on the raod again. for now im just gonna ride it. if i decide to have a motor installed in the future i will be be sure to ask advice from you all before i have it done. by that time i should know more then what i know now about car stuff. when it comes to cars all i know is just to do the preventive maintnance. though i've visit AF i've learn more and more each day about cars . again, than kyou all for your time. keep those advice comming!!

so the problem with my car is the fuel relay correct?... or is it the main relay? what are the differences between these two? how much does one of them cost? where could i get them at or where should i get them?

I have a 92, and I am having the same problem this week! Since Sunday in the 10 times I have started it, twice it did not start. Wait 2 or 3 mins, try it again a couple of times then it starts. A friend told me it could be the relay also. Great! Easy fix! If anyone has more info on which relay to replace and where it is located I too would be greatly appreciative!

heyitsme, I just had the same problem earlier today. i had to sit and wait for like 5 minutes before i could get my car to start again. it happen twice this week. if you found out which relay please let me know ok? i would love to get this problems taken care of. i know everyone here's been telling me it's the relay, but dont know exactly which relay i need to replace. thanks.

heyitsme, I just had the same problem earlier today. i had to sit and wait for like 5 minutes before i could get my car to start again. it happen twice this week. if you found out which relay please let me know ok? i would love to get this problems taken care of. i know everyone here's been telling me it's the relay, but dont know exactly which relay i need to replace. thanks.


Fuel relay and main relay are the same thing. Just what people want to call them at any certian time!!

Thanks chucksnee! That sorts that out. Now, if anyone knows where it is so it can be replaced, we'll be problem free again for another 50,000 miles! Eyescott, it's funny to have the same incident at the same time! If they weren't a year apart I would think our cars were twins sharing telepathic signals.

If it's like a 3rd gen it's attached to the fuse box on the left hand side as you are sitting in the car!

hehe, heyitsme, my car is a 92 si. my wifes car is a 93 so i kept getting the years mix'd up! well, now we know what's our problems right? now all we need to find out is where the main relay is located so we can get it taken care of. i was told it's located somewhere under neath the stearing wheel. i'll drive over to autozone or pepboys this weekend and see if they could show me exactly where it's located.

lay on your back and lookup under the dash (just to the driver's side of the steering colume) and this little sucker is way up there. you probably still can't see it, but it's there. it's on a mount that slides off, or maybe a nut holding it (can't remember exactually). it will test you! cost about 40/50 bucks.

Thanks for all the replies, you guys are outstanding here! I am very appreciative of all info! Eyescott, I will look for it this weekend too. I'll post back if I am successful. Thanks again to everyone who replied!

so did it work?

I have a 91 Prelude and over the last month I've noticed that the car starts and runs perfectly but sometimes, when the engine is hot and it's hot outside, the car won't start. It will crank but not run.

I usually wait for it to cool down and it starts no problem.

I just learned of this problem through a friend who is a mechanic at a Honda dealership here in Toronto. He says that they replace three or four main relays a week on Honda's 10 years and older...especially in the summer time.

I've just ordered a new one and I'll let you know what happens.

he be right. change your battery every 36 months, main and a/c relay every 6 years and drive and smile.

If you are still looking for your relay its below your dash right by the stering colum, if you are looking with your head on the floor mat and you are looking directly up it should be right near the top. On a 92 prelude its a brownish color and the name on it is mitsuba i think, or something close. If you want to test to see if that is the problem you can do what I just did. After looking on the net and calling around I found out you can bi-pass your main relay. If you take your relay off, you can hot wire it through the harness. On a 92 prelude SR (2.3L) you need to take the black/yellow wire wich is your power going to it, it should only get power once you have turned the ignition on, and wire it straight to your solid yellow wire ( i think there is a tiny bit of gray on it). After you do this you should hear your feul pump turn on when you turn your ignition on, and if you take of your bleader nut off of the fuel rail you will see fuel coming out of there. If you try that and it does work, and if you didnt have fuel pressure before then you know that it is your relay that is gone.

where would the relay be on an 87 4ws Si?
Cheers for your help. :)

hmmm, maybe near the same spot, or closer to your fuse box. Do you haev a haynes manual? It gives you a rough idea in there.

You might also have to pull your fuse block off, I read in my chiltons book that its on the back of the fuse block, so you actually have to unbolt it to get to it. But I'm not too sure what year of a prelude that was for.

I managed to change that relay with no problem and the car started with a warm interior after baking in the sun for most of the day.

And then, as I left, I realized that my emergency brake seized! DAMN!

So I jacked up the car, saw that it was my right rear that wasn't turning, took off the tire and released the brake from the top of the caliper. I then immediately disconnected my emergency brake from the lever and drove to NAPA to pick up a cable.

Oh well, I guess it's to be expected in a 13 year old car.

Before anyone changes the relay on their car, try connecting a gator clip to the ground wire on your harness, and then ground that by your pedals somewhere, and see if it makes any difference. I just bought a new harness and it didn't make any difference, and after I grouned the wire like I said above, it turned the pump on and started right up. If this does fix your problem dont cut the ground wire and tap into it that way, splice it so that it almost "Y"s. For some weird reason, after I cut the wire and re-connected a new wire to it and grouned it it never worked, but after I attached it back to the old ground, and ran another ground to a different spot it worked again. Just a tid bit of info that I learnt today.