alright you guys here is my problem, i have an 88 dx hatch with an obd1 b16a and new ls fuel pressure regulator and original oem fuel pump. car runs fine on a full tank, as it begins to get lower 1/2 i will feel a bit of a loss a power, but i mean it is very minute, once there is like 2-3 gallons of gas i feel a bit of hesitation in the motor when i drive it normally, not racing or anything. when i race, i feel a bit of hesitation before vtec (4800 rpm on p30 basemap hondata s300). whether tank is full or not, car always takes a while to start when it is cold. it can be warm but if i let car sit for an hour and i go back to try to start, it still takes a while, which i figured is due to loss of fuel pressure. when it is cold, if i try to start car for 1-2 seconds, stop, try it again for 1-2 seconds it will start immediately on the second try, sometimes i have to do it 3 times. i think it has to do with fuel pressure, but unfortunately i dont have a tester. a local mechanic told me that the cycling of the fuel pump at initial start up(when i turn on and turn off and turn back on) definately means its the fuel pump. what do you guys think?

 

the fuel pump is suposed to cycle when you turn the key on to build system pressure for start up.

if you plan to diagnose this yourself (with assistance from the web..) i would suggest investing in a fuel pressure tester. a cheap one from Harbour Freight should be adequate.

install it, feed it through the hood and rest it on the windshield so it's visible from inside the car. have a passenger keep an eye on it while you keep your eye on the road . get pressure readings for the conditions you mentioned feeling slight loss of power and see if there's a trend.

 

ok but if pressure is low, what will that tell me? fuel pump or regulator?

 

Have to agree with the above^^^.
Until you get a fuel pressure gauge it's just a guess.
As mentioned, the fuel pump will cycle every time you turn on the ign., no matter how many times you do it, it is normal even if there is no loss of fuel pressure when ign. switch is off.
Low or fluctuating fuel pressure can be caused by a bad fuel pump, defective fuel pressure regulator, defective PGM-FI Main Relay or even an old fuel filter. 94

 

Ok but like I said what will low fuel pressure mean? And the regulator is new from a autozone parts store, its like only 3 months old, and fuel filter is 300 miles old, I have an extra new main relay, and ill swap it and see if it makes a difference, I used to be able to hear pump when I turned ignition on, now I don't. Will ls fuel pressure regulator not function correctly on a b16?

 

pump can't keep up with demand, fuel filter is clogged, pressure regulator not working like it should...

you still need to confirm that you are loosing pressure with a tester, and not just having similar symptoms but with different cause.

 

If you do not hear the fuel pump prime when you turn on the ign. you have a problem with the fuel pump, PGM-FI Main Relay, ECU or wiring 05 fuses, because engine runs, fuel pump and PGM-FI Main Relay must work, my guess would be the ECU as it controls the fuel pump, through the fuel pump power relay in the PGM-FI Main Relay, but it is just a guess, you still need to check fuel pressure, if you have the spare PGM-FI Main Relay, plug it in a hope it was the problem. 94

 

ok nevermind i fixed problem, it was regulator, now it starts right away even when cold, and runs perfect thanks