okay quick overview

99 hatch dx
b16a2
4-1 header
2.5 exhaust
intake
no cat

anyways
today trying to drive to school, my a/f gauge started to dip below lean, it wasnt even registering on the gauge, or it was registering only 2 bars of red even at WOT, the car started hesitating, backfiring when applying throttle, then 5 minutes later, my temp gauge started to shoot up so i shut the car off, and limped it back home

reset my ecu, started car, a/f gauge wasnt even registering again, okay, checked codes, only code was secondary o2 sensor, but thast because i have a header and no cat, and that wouldnt affect my a/f readings

pull my plugs, they are all white, so very lean, whats the deal, it just started acting like this today, it was fine last night?!

im stumped! what broke my car!

plugs are also only 15k km old, so i dont think they are the culprit, never changed plug wires

 

i would say since your running lean, then you should check the fuel pump and filter

 

im running a walbro 190 unit thats only like 25k km old, filter on that same condition, maybe the fuel filter in the engine bay, i dont know?

 

sounds to me like your fpr is sticking and or maybe you have an injector thats failing , .... that would not explain the temp increase though .... i have seen in the past where if a coolant temp. sensor if failing , it can affect fuel delivery and temp. at the same time , however that was due to a short in the sensor which caused a the sensor wire to melt through the harness all the way the the dis. block. but thats another story alltogether !

the most common expl. would be a lack of fuel be it clogged filter , bad pump ..or injector , ..... i would look into those first , reguardless of the mileage on either ... things do happen that mileage has no effect on ... keep that in mind

good luck !

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lsed-eg &raquo;</TD></TR><TR><TD CLASS="quote"> .... that would not explain the temp increase though .... </TD></TR></TABLE>

When a car runs lean the combustion temps increase sharply and that would explain it.

I would check your fuel pressure at the rail and see what it is. Because all your plugs were white and not just one it would indicate a total fuel system problem such as a pump, filter, filter sock (on the pump), faulty FPR. Something is preventing your car from getting the fuel it requires.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 00Red_SiR &raquo;</TD></TR><TR><TD CLASS="quote">

When a car runs lean the combustion temps increase sharply and that would explain it.

I would check your fuel pressure at the rail and see what it is. Because all your plugs were white and not just one it would indicate a total fuel system problem such as a pump, filter, filter sock (on the pump), faulty FPR. Something is preventing your car from getting the fuel it requires.</TD></TR></TABLE>

+1

 

k well update, after letting the car sit for about 30 min i drove to school and the car appeared to drive fine, a/f was normal bouncing between lean and stoich like it always does, and no temp increase

im stumped
i did a quick search and found other people experiencing the problem, they pinpointed it as a wire on the primary o2 coming loose, affecting the voltage, and eventually the a/f, but it wouldnt throw a code, replacing the o2 fxied the prob, any insight?

 

ttt

 

well I'd say that unless you have a faulty wire on your primary O2 sensor that your fuel sock may have collapsed temporarily in the tank and starved the pump. Once the car sat for a while the sock unfolded and now it's fine again? It can only be a couple things...

 

well my tank was less then 1/8th full hovering above the bottom hash, i dont know if that would make a difference, but this is weird nonetheless

 

ttt, car was acting up on the way home again!

 

my buddy said i should cancel out the o2 because when i go wot i go into open loop mode, thus no longer reading off the 1st o2

yet i am still running dangerously lean, so i guess im going to focus on the fuel delivery

he also said my fuel pump might be taking a dump, i said well shouldnt it stop working all together, and he said no it might only be operating on partial volts therefore not operating even at oem efficiency.

 

c'mon guys i need help!!!

 

You know where to look, pull your backseat up and lift the pump out and see if the filter sock is ok or if it's collapsing and blocking the pickup on the fuel pump. Check the wires going to the fuel pump and see if they look ok, if those things check out, put a fuel pressure guage on it and see how it looks.

 

just to bring this up, i re-checked my codes and found that i would pull a 65 code (2nd o2) then it would flash one (1) for primary o2, but i thought this one flash was a clear between codes, so i was having a primary o2 code the entire time, grrr