87 ACCORD Fuel pump pumps only in start but not in run mode

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02-18-2005, 09:53 PM
kilgorq

87 ACCORD Fuel pump pumps only in start but not in run mode

I have a 1987 Accord that has a fuel pump issue. I have looked at the Chiltons and Haynes manuals and can not find the wiring diagram for the fuel pump on carb versions. I need to know if the fuel pump on the carb version runs from a mains relay, directly of of the ignition switch, or through another relay. And where it is located. The car will start but dies a few seconds after I release the key to the run mode. Just long enough for it to use all of the gas in the float bowl.
02-18-2005, 10:34 PM
zero.counter

The fuel pump cut-off relay is located underneath the dash around the steering column area.

I can sell you a brand new pump if you are interested!

Welcome aboard BTW! :)
02-19-2005, 07:33 PM
kilgorq

Quote:

Originally Posted by zero.counter

The fuel pump cut-off relay is located underneath the dash around the steering column area.

I can sell you a brand new pump if you are interested!

Welcome aboard BTW! :)

Thanks.

So lets see if I have this right. On carbureted cars. The fuel management system is like so.

In the RUN mode they maintain a fuel pressure between 3 and 7 lbs this is controlled by the fuel pump cutoff relay. But when you go into the START mode the fuel pump cutoff is bypassed and the fuel pump runs constantly.

The sensor that measures the fuel pressure is in the carburetor. And when the fuel pressure meets the preset, it turns off the pump via the relay.

So a valid test would be to bypass the cutoff relay and see if the car will run properly.

Some of the symptoms would be. Ruogh Idle or loss of power (Almost like a bad power valve.) Starts and then dies immediately or shortly after it starts.

I played with the car a little today and got it to run for about 15 minutes. But it would not idle and it acted like it had a bad power valve.
02-20-2005, 07:00 AM
shepherd79

actually you got some things mixed up.
lets start with START. when you turn your key, the pump will come on and shut off.
this will deliver extra fuel into the carb if needed and it will build up some pressure.

after you start the car, the pump will kick in all the time. it will be running untill yo ushut off your car.
the only thing that keeps the fuel flowing is a little needle in the carb. it is controled by a float. when there is enough fuel the needle will close the fuel line. the pump is still running at the same time.
so if your strats, but shuts off after, itis your main relay.
03-21-2005, 07:17 AM
iron

Quote:

Originally Posted by shepherd79

actually you got some things mixed up.
lets start with START. when you turn your key, the pump will come on and shut off.
this will deliver extra fuel into the carb if needed and it will build up some pressure.

after you start the car, the pump will kick in all the time. it will be running untill yo ushut off your car.
the only thing that keeps the fuel flowing is a little needle in the carb. it is controled by a float. when there is enough fuel the needle will close the fuel line. the pump is still running at the same time.
so if your strats, but shuts off after, itis your main relay.

According to the honda shop manual I have (the silver one) the fuel cut off relay sends pulses to the fuel pump everytime the ignition coil fires. So it should be pumping both when cranking the car and when the car is actually running. An ingenious idea much better than fords solution for a fuel cut off relay IMHO.

Trouble shooting the relay is a job for a contortionist. It's on the rear side of the interior fuse box.

If you'll go to http://www.pauldesign.ru/honda/shopmanual.html and download the 1987 supplement (62se321.pdf) the fuel pump relay trouble shooting's on page 12-132. In the silver honda shop manual it's page 11-45.
03-21-2005, 10:11 AM
A20A1

Quote:

Originally Posted by kilgorq

Thanks.

So lets see if I have this right. On carbureted cars. The fuel management system is like so.

In the RUN mode they maintain a fuel pressure between 3 and 7 lbs this is controlled by the fuel pump cutoff relay. But when you go into the START mode the fuel pump cutoff is bypassed and the fuel pump runs constantly.

The sensor that measures the fuel pressure is in the carburetor. And when the fuel pressure meets the preset, it turns off the pump via the relay.

So a valid test would be to bypass the cutoff relay and see if the car will run properly.

Some of the symptoms would be. Ruogh Idle or loss of power (Almost like a bad power valve.) Starts and then dies immediately or shortly after it starts.

I played with the car a little today and got it to run for about 15 minutes. But it would not idle and it acted like it had a bad power valve.

7 psi... I doubt it

3.2 is the best I got from the stock pump without a reg. and it'll drop down to 2 from time to time.

The power valve has nothing to do with idle... I can disable it or leave it on constantly and the carb will idle... the power valve is for enrichment @ WOT or when vacuum drops from enough throttle.

the only time the pump will shut off is when you rev too high... this is why or because it's tied to the ignition.

.
.
.
03-27-2005, 09:02 PM
DanG86LX

kilgorq>> ..I played with the car a little today and got it to run for about 15 minutes..
..then it may not be ur fuel pump or cut-off relay after all. Look through the little window on driver side of carb for gas level when it stops (air box off).. Seems like u got an idle prob.
03-27-2005, 09:07 PM
AccordEpicenter

carbed fuel pumps have to be the most little dick pumps ive ever seen... and i mean evAR
03-29-2005, 08:16 PM
Alfred Febian Gani

delorto; need info

hello guys
i have an a20a1 that will be upgrade to 4 barrel using delorto DC series. i'll forget the exact series (i'll check it later).
one of the member had discuss also about blow thru and draw thru, and my problems are:
1) after i use these 4 barrel, should i change the fuel pump? what kind and type of fuel pump that will give me adequate low pressure and high volume flow of fuel?
2) i'll using CT20 turbo from toyota (please advise about this CT20), could it be use for my delorto carb.

thanks bros...

alfred
03-29-2005, 11:18 PM
A20A1

well depending if you run blow or draw thru will change the type of pump you need.

For blow thru the psi will have to be 3-6 psi greater then the air pressure in the carb or the fuel wont flow. The fuel pressure will have to increase as boost pressure increases to maintain a higher fuel pressure then air pressure. You'll need a boost sensitive 1:1 FPR ( fuel pressure regulator) along with a pump that will put out enough pressure for the highest boost level. Say if you run 12 psi boost max, so the fuel pump should at least put out 18 psi ... the reg will take care of the rest. You may want to double check that though.

For draw thru the pump can have lower pressures but it still needs good flow... look into aeromotive pumps and walbro pumps.

but to answer your question; yes you need to change the fuel pump... you also need to change the fuel lines since carb fuel lines are not ment to handle high pressure.
05-03-2005, 11:00 PM
Alfred Febian Gani

thanks for your info boss.

and sorry before, because i forgot to tell you that last month when i'm asking you about which is better draw or blow?, my mechanic just explained to me that my engine block couldn't handle boost more than 0,5 bar (7psi), so we decided it to re blue printing my engine to rush in N/A only. i'm still using my original carb, and i already take all choke system and vacum lines.

now my accord get's better acceleration. oh yeah, another question...
my mechanic do something with my pistons and the cylinder block, he use overbore 100 for the piston, just for compression purposes. i hope it's not dangerous. most car use only overbore 25 or max 50. but he's giving me guarentee for my engine, and he assure that's nothing will happen with my car, because he also reduced the piston weight. please i need your information about risks doing overbore more than 50.

just like u say, i will replace my fuel pump for better fuel flow, because after the modification and upgarding the compression, i no longer using lower octane gasoline. it's kinda piss me off a little because of the scarsities and price of high octane gasoline is killing my wallet every weeks...

is it normal that my car sometimes knocking in the daylites when using air conditioner in a high gear...
why these happen? is it about lean? or my timing just too advanced/retard?

thanks for sharing bro...and thanks before for your information
wish to see u in person for consultation ^_^

Bye, GBU

Quote:

Originally Posted by A20A1

well depending if you run blow or draw thru will change the type of pump you need.

For blow thru the psi will have to be 3-6 psi greater then the air pressure in the carb or the fuel wont flow. The fuel pressure will have to increase as boost pressure increases to maintain a higher fuel pressure then air pressure. You'll need a boost sensitive 1:1 FPR ( fuel pressure regulator) along with a pump that will put out enough pressure for the highest boost level. Say if you run 12 psi boost max, so the fuel pump should at least put out 18 psi ... the reg will take care of the rest. You may want to double check that though.

For draw thru the pump can have lower pressures but it still needs good flow... look into aeromotive pumps and walbro pumps.

but to answer your question; yes you need to change the fuel pump... you also need to change the fuel lines since carb fuel lines are not ment to handle high pressure.