At times my fuel pump primes loudly with a loud "tock" sound once I turn the key. But sometimes it just makes a soft little "zzzzz" sound. Mostly when it gives the loud "tock" sound, the car performs very well and starts up with minimal cranking. Otherwise the cranking is longer. Is this a symptom of fuel pump failure?

 

Possibly, try replacing your fuel filter first before considering the pump, see if that makes a difference.

 

the reason it thumps and then starts better is because the pump is deadheading at its max presure then car starts better, when you hear the softer buzz its because the pump is building up to pressure, u may have an injector leaking down causing it to loose residual pressure, with the lower pressure thats why the car doesn't start as well, i got a walbro 255 and i notice the same thing in my eg,

 

You mentioned a leak in one of the injectors. Would it be a gasket leak or do I have to replace the entire injector? I do not smell petrol in my engine bay. I forgot to mention that my idle is lumpy and the car seems like its about to stall whenever I DO NOT get the thump sound.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by garyc17 &raquo;</TD></TR><TR><TD CLASS="quote">You mentioned a leak in one of the injectors. Would it be a gasket leak or do I have to replace the entire injector? I do not smell petrol in my engine bay. I forgot to mention that my idle is lumpy and the car seems like its about to stall whenever I DO NOT get the thump sound.</TD></TR></TABLE>

you would have to replace the o rings maybe

 

my car does the same thing, if its the injector, the problem is the pintle not seating which lets fuel leak into the cylinder, it also could be the pressure regulator, i'm not sure what makes the pump hold residual pressure , i think that there is a check valve made into the pump, if you clamp the return side of the fuel line after the pump has primed and the fuel pressure drops its most likely an slight injector leak down

 

Any other methods of testing for a faulty injector? I don't have a fuel pressure gauge. My fuel rail, injectors and pressure regulator are all original Honda parts. B18C5, H22 and B18C5 respectively.

If its any help, sometimes I hear some soft explosions at the rear of my muffler in the midst of a gear shift.

 

Any help appreciated.

 

i'm not sure how you'll be able to check it without a gauge, and depending on the noise im not sure about that either, sorry i can't be more help full

 

even with a guage its still hard to tell, since the PSI could be correct, but what about the LPH its putting out?

it could be tossing up 45psi, but putting out less than a brazillain nun.

check your plugs for a lean condition at WOT.

 

My plugs look fine. I have replaced fuel filter, plug cables, caps, rotors, filter, TPS sensor, engine oil, oil filter. Cleaned my IACV with carb spray. I think the carb spray fluid might have got into my TPS and damaged it. After spraying, my car had wierd idling problems. My car would want to stall(revs hunt between 300~500rpm) after a bad clutch control at the lights. It would also stutter at constant throttle position on the highway. The stuttering is feels like getting on and off the gas very quickly. Feels like fuel starvation at times. It also happens when I contact an uneven road surface. If I floor it, it goes away. I hear knocking sounds from my engine bay when cruising. Could it be my tappets since my PowerFC is not picking up knock. Or the knock could be a sign of water in my fuel tank?

I replaced my TPS few hours ago and all has been fine since. Will monitor it and update you guys.

Will a faulty MAP sensor cause this? Can engine oil entering the throttle body from the valve cover through the intake pipe cause TPS or IACV to go bad resulting in the stuttering?

 

Since I swapped out my TPS 2 days ago, all has been well. Still monitoring. Why does a TPS go bad so often? It has only been 6 months since my last swap.

 

TPS's are sensitive little sensors that detect the angle in which your throttle butterfly is opened, and that is what dictates fuel input to the motor. Without it, if you were to just lightly tap the gas, it would rev up as if you had just mashed the pedal to the floor.

Since my swap, mines acted up once in awhile too on occasion. I just turn the car off, and back on again, and its gone for another week or so, lol. But its strange, i can bring the RPM up to say 2000, just lightly pressing the gas, and it will lightly bounce there, like i have a 2-step system active ( Launch control for all you noobs). I wish i had a 2 step system, lol.