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View Full Version : 86 Accord LX Carb - main relay equivalent?



ralbach
11-25-2009, 02:25 PM
Had all the symptoms of a bad main relay <would not start when climate warm, etc.> BUT after many hours of part removal I did some additional internet searches and it was suggested that my carburated vehicle does not have this part.

So what is the equivalent piece that is having this occasional problem?

I can hear the clicks mostly when it worked but of course can't tell now that all is taken apart.

Sadly the 2nd edition shop manual I own doesn't really say much - it does mention the fuel cut-off relay but does not say much about it in terms of whether it is a likely suspect - don't want to put everything back together until I get an educated answer.

My thanks in advance for any insight you can offer.

-Robert

Bass Man
11-25-2009, 03:43 PM
Well, what is exactly wrong with your carb? Do you have smog?

ralbach
11-25-2009, 07:48 PM
problem was that I would occasionally be unable to get gas to the carb when starting - this seemed to happen when the interior of vehicle got warm - similarly after driving some time the car might sputter

Several sites - Tegger and others suggested that the main relay was the cause as the sodder joints were cracked - problem is an 86 Accord w carb does not have a main relay

so I'm wondering if there might be an equivalent to the main relay in a carb system

thanks

Bass Man
11-25-2009, 07:59 PM
I'm about 80% sure it's Carb Icing. (http://www.3geez.com/forum/showthread.php?t=63643)

headbanger
11-25-2009, 09:26 PM
it has a fuel cut off solenoid in back of fuse box that is the only thing I know of.I reckon somehow if it dont get it signal it keeps fuel from flowing.

ralbach
11-26-2009, 11:18 AM
I suspect you are correct.

I am hoping somebody who has suffered the same issue or far wiser than I could confirm that is the case.

Thanks for the suggestion and a happy thanksgiving to all.


it has a fuel cut off solenoid in back of fuse box that is the only thing I know of.I reckon somehow if it dont get it signal it keeps fuel from flowing.

guerrero
11-26-2009, 11:19 PM
have you check the sifter in your fuel pump and fuel pump might be starting to give out. i just had this problem. the car would run but then it would die in the middle of the street or freeway. it would start in 5 hours to a day later and would run a couple OF HOURS OR DAYS AND DO IT AGUEN.I CHECKD THE AFTER MARKET FUEL PUMP AND IT WAS BAD AND THE SIFTER WAS BLACK NOT BROWN (AFTER MARKET HAS A CROME FUEL PUMP AND WHITE SIFTER, AFTER MAKET SIFTER TURNS BROWN WHEN OLD, ARIGINAL HAS A GREEN PUMP AND ORIGINAL BLACK SIFTER) I CHANGED IT, INCLUDING THE FUEL FILTERS, CLEAND THE CARB, RE-ADJUSTED IT. CHECK IF THIS IS THE PROBLEM BUT IF YOU HAVE A AFTER MARKET PUMP AND IF ITS BLACK YOU NEED TO TAKE THE TANK OFF AND DEEP CLEAN IT. if its the original pump its time to get a new one. you could get a after market one or dealer to be safe. I hope this helps

nathan.chase
11-29-2009, 02:03 PM
We had a no start situation and I have strong reason to believe it would be the main relay in any other car. After spending a few evenings looking for the dambed relay we couldn't find it. Had just about everything ripper out from under the drivers seat dash and nothing under the passenger (didn't remove the glove box though). So... If there isn't a main relay what else could work in its place? Fuel cut off relay perhaps? how do you test that and how is it controlled? (ecu) suggestion?


Here is what I have diagnosed:
1. no start
2. started with starter fluid -> No fuel at carb
3. no gas pump sound with key on -> fuel pump issue
4. No electricity at fuel pump connection in trunk -> electrical issue not pump issue
5. Good fuse and electricity at 20amp fuse for fuel pump and ECU
6. That leaves bad wire between the fuse box and the pump or a bad relay somewhere along the way.


What is up with these carbs?

thanks for your help
-nate

nathan.chase
11-29-2009, 02:11 PM
oops

nathan.chase
11-29-2009, 03:42 PM
Thinking it might be the fuel cutoff relay. I pulled it and tried jumping the 4 terminals in all combinations. The only thing that happened was burning a few fuses when jumping terminal 2 and 3. Any idea why this would happen? I guess this means the relay is good, the circuitry looked good.

From another website they mentioned that power from the distributor on the blue wire is needed to run the relay.I found this to be essentially low (.5v).

I replaced the fuse and tried putting 12v into the blue and the black/yellow lead on the coil and still no whirring of the fuel pump.

any help would be awesome

lostforawhile
11-29-2009, 04:09 PM
Thinking it might be the fuel cutoff relay. I pulled it and tried jumping the 4 terminals in all combinations. The only thing that happened was burning a few fuses when jumping terminal 2 and 3. Any idea why this would happen? I guess this means the relay is good, the circuitry looked good.

From another website they mentioned that power from the distributor on the blue wire is needed to run the relay.I found this to be essentially low (.5v).

I replaced the fuse and tried putting 12v into the blue and the black/yellow lead on the coil and still no whirring of the fuel pump.

any help would be awesomethe blue wire from the distributor? thats probably the tach output to the computer, both of the main relay coils are operated directly by the ecu, looking at the diagram right now.

A20A1
11-29-2009, 04:15 PM
FOR ralbach:
is your choke working? did you remove the lid of the carb and check to see where the choke is positioned and if it starts?

Is the fuel in the float bowl?

What year is your car? Or did you mean second gen when you said second edition?



FOR natha.chase:
Did you try the pump directly to the battery?
Remove the fuel line from the pipe near the rear filter or from the rear filter itself and check fuel flow by routing the fuel line into a gas can.

If the pump works, work you way to the carb and check flow from the fuel line connecting directly to the carburetor.

At least then you'd know your filters and pump are good.


EDIT: Sorry I missed the post where you said no power to pump.
I'm not sure if power will go to the pump constantly unless the car is running or the ignition switch is in the right spot?
I know the ignition switch does send a priming signal, however it only lasts a second or two, then again I could be mistaken on both accounts.

In any case you could always consider having the fuel pump ran separately and hooked to a switch, which could double as an anti theft device.

nathan.chase
11-29-2009, 07:57 PM
Sorry I jacked the forum. I tried directly connecting to the fuel pump and nothing. Then I tapped the pump and it ran normally. So its a burnt out fuel pump. can these be changed though the truck or do you have to drop the whole tank?

What I did wrong to believe it was an electrical issue: (for future users with a no start)
1. when you first turn the key the pump gets a very short burst of electricity and then 0 until the engine turns over or you have the key at start position. I missed this and read 0. The fuel pump is very quiet and you really can't hear much of a whirring unless you are in the trunk and its quiet around you. Directly connecting to the battery is a good way to check the pump.

2. there isn't a main relay in the carburetor accord, just a fuel cut off relay in the back of the fuse box.

Hope this helps anyone else with a no start and thank you for your ideas.

-nate

A20A1
11-29-2009, 10:20 PM
Take off the 8? bolts for the lid and pull the pump assembly out.

Anyways glad you found the problem.