So I have a fresh block at 20 over, and a brand new head after throwing a rod on the original motor. Everything is stock save for a K&N filter in a stock box and a Hondata intake manifold gasket. I think I have a Mugen thermostat and switch too. New motor has about 300 miles on it.

Fuel pressure is at 44, 54 pinched, after the filter which is perfect according to the integra shop manual. I figure this means that the lines are clear and filter isn't clogged. The car did sit for almost 3 months while waiting to get fixed.

Tried switching the MAP sensor, no luck there - though I am currently trying another one because the original donor was already throwing codes.

The FPR valve solenoid or whatever it is behind the throttle body IS holding pressure.

Could not find and vacuum leaks, and we welded an exhaust leak that we found shut.

I have a brand new primary o2 sensor, and as far as I understand the secondary o2 has nothing to do with running lean.

The only thing I can think of that is left would be the injectors, but I'm already on my second tank fill of fuel with injector cleaner added. And I AM running premium fuel, so that's not it either. New injectors are the next step though as far as I can tell.

The car never threw this code before and everything was switched over from the old block to the new one. Old block had 123k miles on it.

Is it possible that the IAT sensor could be causing this? Am I wrong about the secondary o2? How about the TPS sensor?

This is all confusing because the car is running so well. No loss of power, no bogging that I can detect. Does anyone have any ideas or input? Any help is appreciated.

I also threw a code 90 (1456) which is the infamous "gas cap" code - I got a new gas cap and it hasn't thrown it since. Along with that I threw a VSS code, but I cleared it and that hasn't come back either - switched the ground by the thermostat housing but that's it.

Discuss.

 

WRT the fuel pressure, for a B15C5 the manual says 47-54.
Manual further states 40-47 for a B18B1 and interestingly it said for the B18C1 it should be 48-55.

Stock or an adjustable fuel pressure regulator?
Have you changed the fuel filter recently/ever?

Seems the fuel pressure might be on the low side ... leaning to a fresh fuel filter or upping the FPR (if you have one) adjustment.

Or ... lets just set up something so I can buy yor car!
Care for an 06 Si plus some cash?? hehe hehehe

P.S. here are the rest of the probable causes listed for code P0171
fuel pump insufficient flow/pressure
fuel feed line clogged
fuel pressure regulator stuck open
fuel filter clogged
fuel injector clogged/air inclusion
gasoline doesn't meet spec
Primary HO2s (sensor 1) detiorated
Valve clearance
Exhaust leak

Best of luck ....




Modified by zygspeed at 9:31 PM 10/10/2007

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">WRT the fuel pressure, for a B15C5 the manual says 47-54.
Manual further states 40-47 for a B18B1 and interestingly it said for the B18C1 it should be 48-55.

Stock or an adjustable fuel pressure regulator?
Have you changed the fuel filter recently/ever?

Seems the fuel pressure might be on the low side ... leaning to a fresh fuel filter or upping the FPR (if you have one) adjustment.

Or ... lets just set up something so I can buy yor car!
Care for an 06 Si plus some cash?? hehe hehehe

</TD></TR></TABLE>

Stock FPR so I'm going to get a new filter tomorrow because it's still the original one. If it's not that, I'm gonna throw in some new injectors.

If that doesn't work, I'mma blow it up.

Civic Si? Hmm.. any chance you got a Frontier? Hah!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SoCal ITR &raquo;</TD></TR><TR><TD CLASS="quote">Civic Si? Hmm.. any chance you got a Frontier? Hah!</TD></TR></TABLE>

No, but I have an AEM CAI for it along with a DC race header and exhaust that are brand new (never been installed).
Not like you're in So Cal or anything ... but a reflashed ECU from Hondata might take care of that. LOL!

 

recheck valve adjustment

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slo blue &raquo;</TD></TR><TR><TD CLASS="quote">recheck valve adjustment
</TD></TR></TABLE>

Maybe.. but after only 300 miles?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SoCal ITR &raquo;</TD></TR><TR><TD CLASS="quote">

Maybe.. but after only 300 miles?</TD></TR></TABLE>

I check my valves repeatedly after a fresh build regardless of mileage. Things always "settle" so I like to be safe than sorry. Not sure if thats the problem but it certainly doesnt hurt to spec them out again.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slo blue &raquo;</TD></TR><TR><TD CLASS="quote">recheck valve adjustment
</TD></TR></TABLE>

I had a code 45(too lean) after my timing belt/WP/valves adjusted. I spent some time researching, adjusting items, replacing fuel pump among other things. In the end my issue was due to improper valve clearance by the shop that did my timing belt and adjusted my valves.