1991 cb7 dies, starts after 5 min. then dies again. Main Relay?

[Ice D]

Today I drove my kids to school and noticed a faint clicking noise coming from behind the dash when I would start it. I thought that's strange, a relay clinking? Then I was driving my wife into town about an hour later, the car had been running for about 1/2 an hr. I pull onto the on ramp and the car bogs down and dies. It didn't start for a few min. at first it would start up and die right away. I thought I could hear the fuel pump priming but it was hard to tell with the traffic. Then after a few min. I started right up, I drove for about one minute then it died again. It did this three time till I coasted to an exit., where the car is still parked.

My question is can the main relay cause the car to die after it is running?

My eg civic's relay would act up in hot weather only and prevent it from starting not cause it to die when it was running.

It seems to be giving me the symptoms of a bad main relay, but could some thing else be causing this?

[guam671]

I would check the main relay first..

DIY

http://www.cb7tuner.com/vbb/showthre...ght=main+relay

and one from off site

http://techauto.awardspace.com/mainrelay.html

and then it could be your fuel pump..

hope this helps.

[dlatino]

what he said ^^^^^

i had the same symptoms and it was my fuel pump .
My relay was new so i ruled that out.

Check the relay first

[DarkHusk11]

^ well usually when the main relay is failing once it starts it starts its when you turn it off thats the problem. If you turn it off and try to start it right away it does nothing then its most likely the relay. A trick is to leave the doors open for a few min to let the relay cool down.

Another thing i noticed when mine broke was that the check engine light doesn't turn off when you turn the ignition on. It usually turns off after a few seconds.

[Ice D]

I re flowed the solder, that didn't fix it, then I swapped it with one from my civic and it is doing the same thing. It's starting only after it sits for 10 min, then dieing.


The main relay is clicking which means it's working, right?

Is there a separate fuel relay or is it combined in the main relay?

I cant tell if the fuel pump is coming on, with the power seat belts it's too noisy.

I am now going to crack open the banjo bolt on the fuel rail to see if there is pressure.

Any other ideas guys.

[Ice D]

quote from http://techauto.awardspace.com/mainrelay.html

{When I turn on the car the main relay starts clicking. I changed it out and still the same thing. What is causing it?

The main is getting low current. The result is a fast clicking relay. The current comes from the battery. The ECU then outputs the current on pin A7 on the ECU. The fix is to make sure the car battery is strong, connections tight and fully charged. Then make sure that the check engine light is not on and the ECU is properly grounded.}

This could be something.

[Ice D]

Is there any easier way to check fuel pressure? On my car the fuel filter is low on the firewall and my pressure gauge won't fit on it.

[Ice D]

^ well usually when the main relay is failing once it starts it starts its when you turn it off thats the problem. If you turn it off and try to start it right away it does nothing then its most likely the relay. A trick is to leave the doors open for a few min to let the relay cool down.

Another thing i noticed when mine broke was that the check engine light doesn't turn off when you turn the ignition on. It usually turns off after a few seconds.

Mine will start, just not stay running. Maybe my fuel gauge doesn't work right and I'm low on fuel.

[deevergote]

You are assuming the issue is with fuel. It could just as easily be a spark issue. Before you start throwing parts at the car, identify the problem. Otherwise, you may create new problems.

[mtnbikaah]

Mine will start, just not stay running. Maybe my fuel gauge doesn't work right and I'm low on fuel.

Put some fuel in man! I had a similar problem when I ran my car low on fuel. It would run for about 2 seconds and quit.

[Ice D]

I am getting no fuel pressure. The main relay is clicking and no noise from the pump.

I am having a hard time finding the fuel pump. I traced the lines back and they bend up over the tank near the filler neck but I don't see the pump anywhere. I pulled out the back seat and see a cover plate to what I thought was the pump but I didn't see any lines coming from it so I think that was the sending unit. I listened to the gas tank area when my brother turned the key to on and heard a faint noise. I opened up a banjo bolt on the fuel rail and cranked i over and got no fuel. There is a bunch of clicking going on under the steering column. Onetime that I tried to start it I turned the key and the was about 8 clicks in rapid succession So could this be an indication of the ignition switch going bad. I forgot my multimeter so I did't get to test voltage to the pump and I did't check the grounds to the ecu.

Also what is the metal cased module that looks like an ecu sized case on top of the brake pedal area. By the way both that case and the main relay were not attached to the kick panel and were just placed so they wouldn't hang at you feet so I suspect someone has been messing with this before.

And I added gas btw.

Do I have to drop the tank to remove the pump?

This morning it started for 30 seconds and they died. It got towed home but is pouring rain out and I don't want to get soaked.

[H23CB7]

Sounds just like my sisters accord. I replaced the pump in hers and it works every time. If your getting no pressure from the pump then i would say its the pump. But if your going to replace it then the proper way is to drop the tank however, myself and a few other people on this site have cut a hole behind the back seat where the pump sits at for ease of access without dropping the tank. Now if your not wanting to have a hole in your trunk then i would suggest not to do this as there are some risks doing it this way with fuel lines being right under the sheet metal. Before doing this I would double and triple check the main relay as that is the easiest to fix.

[rockredtail]

yes you do have to drop the tank to do a pump

[deevergote]

Please use the "edit" button instead of posting repeatedly every time you have a new thought to add.

Yes, you have to drop the tank to change the fuel pump, unless you want to cut a hole in the metal above it (people have done it... I would not, personally.) Be prepared to replace all the mounting components holding the tank in place, as they may be rusted and rotted by now. Removing them may break them.

If you are sure your relay is working, and you have no fuel pressure at the rail, then the fuel pump is very likely the problem... unfortunately.

[F20A CB7]

Sounds just like my sisters accord. I replaced the pump in hers and it works every time. If your getting no pressure from the pump then i would say its the pump. But if your going to replace it then the proper way is to drop the tank however, myself and a few other people on this site have cut a hole behind the back seat where the pump sits at for ease of access without dropping the tank. Now if your not wanting to have a hole in your trunk then i would suggest not to do this as there are some risks doing it this way with fuel lines being right under the sheet metal. Before doing this I would double and triple check the main relay as that is the easiest to fix.

I wanna see picsss please.