nemeii

manual, 97, civic ex
p75 ecu


I was driving and the check engine light came on accompanied with some rough idle, code 14. So i pulled over thinking it was this damn speed sensor wire that has been giving me trouble and check it, nothing obvious wrong. So I get back in and try to start it up and bam it wont start, the starter engines and rotates the crank.

I noticed that the fuel relay wasnt engaging either. So i test continuity to the fuse and its connected and then i tested continuity to the fram and supposedly there was a short. So i traced it back to the fuse box and its coming from the supply(battery) side. So i figure do a quick fix to get it home and then take it all apart to find the short right? wrong, even when i got juice to the relay without a short and it actuated, i tried cranking it and it still wouldnt start, like i said it cranks but almost as if no ignition or fuel... i think its fuel cuz the relay doesnt turn off after a few seconds when it does get power.

I just got the ecu and i saw in another thread that if the check engine light doesnt go off after a few seconds its a bad ecu, but im wary of that belief.

by the way the reason it threw a code 14 is because the iacv gets powered up by the fuel relay that wasnt actuating and suppling power. However what confused me was that if it wasnt getting power when it was running. How did the fuel injectors, etc. work?!?!

Any thoughts gentleman?


Modified by nemeii at 7:53 AM 8/10/2008

94EG8

blown alternator fuse under the dash will cause this if i remember correctly, bad thermostat ground will also cause the check engine light to stay on and cause the engine to not start.

nemeii

nah fuse 15 (alt. fuse) was still good. I checked it first actually because its caused me so much grief in the past.

However seeeing as how i was jiggling that speed sensor harness around it mightve broken the old decrepid thermostat ground wire as it is literally right above the speed sensor. Let me check.

Any ideas as to why my iacv would through a code randomly while the fuel relay was operating (i assume because i was driving for like 20 minutes after the light came on and the injectors obviously mustve been firing) and then only after i turn it off, nothing seem to work??

Or why there would be ground continuity from the supply side of fuse 13 (fuel relay fuse) as well as 11+ volts? to me that says shortcircuit from crappy wires but even when i supply it with power it doesnt actuate after fuel line priming either.


meh... ::grimace::


Modified by nemeii at 8:30 AM 8/10/2008

94EG8

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nemeii &raquo;</TD></TR><TR><TD CLASS="quote">Any ideas as to why my iacv would through a code randomly while the fuel relay was operating and then after i turn it off, nothing work??</TD></TR></TABLE>

No, not right off the top of my head. on the off chance something inside the IACV shorted you could try unplugging it and seeing if the car will start though.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nemeii &raquo;</TD></TR><TR><TD CLASS="quote">Or why there would be ground continuity from the supply side of fuse 13 (fuel relay fuse) as well as 11+ volts? to me that says shortcircuit from crappy wires but even when i supply it with power it doesnt actuate after fuel line priming either.</TD></TR></TABLE>

That I can't explain, someone else might have some insight though.

nemeii

yeah i tried unplugging it, maybe it threw the code due to low voltage then after i turned it off maybe it shorted worse i think if i can fix the fuel relay problem though the iacv will be fine.

nemeii

You sir, were completely correct and im embarassed to say i shouldve kown to look.

the ground wire going to the thermostat was broken, kinda pisses me off because i just swapped themotor two months ago and i re-enforced all the wire connections especially that one because it has broken before.

so sure enough i cut through 2layers of electrical tape as well as the plastic sheathing i had covering it and bam, broken wire.

Started right up and had a perfect idle, thank you

94EG8

No problem, i had something similar happen a while back. Car would start and run fine, put it in first and start to let the clutch out and it wanted to stall, shove clutch in and it would come back. I had to rev it up to about 3 grand or it would stall, drove it like that for a week until i could get it home to look at it. I had it running and just happened to move the wiring harness and it shut off, i moved the harness back and forth and i could hear the purge solenoid clicking, hmm. wires broke halfway through where they went into the ring terminal on the thermostat and when the engine moved it wanted to shut off, easy fix, but it could have been a pain to diagnose.