Yosshaa

I have a 2000 honda civic ex 1.6l vtec, 162,xxx miles with a misfiring problem.
car runs like ****, except for at idle.

throws codes p1399 (random misfire) and misfire codes for cylinders 1, 2 and 4.

Thought for sure it was the dizzy
replaced dizzy, cap, rotor, and plugs.... didn't change a damn thing

My buddy (an acura tech) helped me do a valve adjustment.
didn't change a damn thing.

checked the timing..DEAD ON

did a compression check... compression read low so we concluded head gasket as the motor has had an over heating problem in the past.

tore the head off... head gasket looked fine... took the head to a machine shop and it was straight as can be.

Valves are all tight and hold water.

The cylinder walls were glazed so we figured the piston rings are so worn that they were causing low compression and misfires.

Did a quick hone job and replaced the rod bearings and piston rings, cleaned the carbon off the pistons and slapped everything back together, reset the timing and...
didn't change a damn thing

we changed the map sensor, fuel filter, tps sensor, and even tried another new dizzy.

nothing! car runs fine at idle, timing is straight, when you hit the gas the car runs rich as hell, like the timing is off and the gas is being blown right out of the exhaust before ignition.

we are left to believe its the ecu or crank position sensor....

anyone have a similar problem??

Yosshaa

I will also add the car doesn't rev past 3000.... not because its in limp mode jus because the timing is so far off.

which leads me to believe ecu or crank position sensor.

hondamark35

i know this doesn't help you solve the problem...

..but did you really rebuild a motor and put several hundred dollars in parts into it to get rid of a missfire code instead of buying a Honda factory service manual and finding a diagnostic flow chart for code P1399?

i'll try to get some info for you this evening if i get a chance.

Yosshaa

dizzy bought and returned=$0
valve adjustment=free

buddys spare parts sensor checks=free

fuel filter 8 bucks

headgasket 40
rod bearings 30
pistons rings 35

pizza and beer 50

the rod bearings looked like ****, the cylinder walls were glazed, and the pistons had signs of blow by.

for about $150 bucks we got a **** load done. Too bad we still haven't fixed the damn problem.
which is what this thread is about.

Jimster480

alright well you have basically rebuilt the whole motor now XD

I would say its the ECU. I had a similar problem on my car. If its running rich as hell, have you checked the reading from the map sensor? In my car one of the wires on my harness that provides power to the map sensor was partially broken and the map sensor was reading 10PSI of boost 24/7, and the TPS thought that you were @ 50% throttle all the time. It was pretty bad, i got it to run fine at idle but as soon as i stepped on it it would start to flood out.

92sihbk

have you done a leak down test on the engine? maybe a faulty injector? when you say it wont rev past 3000 rpms, is it because its breaking up/ sputtering?

hondamark35

haha, that's either a lot of pizza and beer or very good pizza and beer! it's the highest priced item in your list

hondamark35

i'll relay the list from the factory service manual relating to random misfire-

possible cause

-fuel pump insufficient pressure, or flow
-clogged fuel line
-clogged fuel filter
-fuel pressure regulator stuck open
-[EGR malfunction] Y5 only
-distributor malfunction
-ignition coil wire open, leakage
-ICM malfunction
-MAP sensor range/performance, poor responce ('96 models)
-carbon deposits on valves
-low compression
-IAC malfunction
-VTEC system malfunction
-O2 sensor circuit

since you've basically replaced the entire ignition system already, i would start with the fuel system. check the pressure, should be 46psi with the vacuum hose to the regulator disconnected and pinched and 36psi with it reconnected.

boxeocampeon

did you replace the ignition wires?

Yosshaa

wires were replaced 14 months ago, and tested to make sure they are firing.

i replaced the fuel filter and the car is running rich in all cylinders... its getting fuel.
we also took the hose off the regulator... no change.

thank you for the info!!!!

boxeocampeon

maybe its a clogged injector or ****ed up fuel pump try running a fule system cleaner its worth a try

boxeocampeon

he just said that code gave him misfire in cylinders 1 2 and whatever it never says what the exact problem is.

Yosshaa

running two bottles now... no difference

hondamark35

yeah i gotcha. when i first read his post it sounded like he had spent all this time and money throwing parts at it without any logical diagnosis, but he described the situation better in another post, and it made sense.

Yosshaa

ok so ive tried everything but these 4. of those options i don't think its the o2 sensor as it idles fine. i dont think its a vtec malfunction because the motor screws up before the vtec crossover point.

iac or icm? what exactly do those entail im not familiar with them.

Anon51

dunno what ICM is but i'm going to assume ecu. and iac is idle air control. (back of the intake manifold or if its an automatic it'll be under the TB(throttle body)

90Rexx

no cylinder 3 logged misfires correct?

1,2 and 4 only??

hondamark35

i'm thinking ICM is ignition control module sometimes called the ignitor.

Yosshaa

correct. i think the cylinder is getting so hot its still firing... its also the cylinder with the worst compression

DustinRose

im working on a 99 ex that is having the same codes, and same issues
it runs poorly, and even stalls
p1399
just rebuilt the block for them

boxeocampeon

and you dont have a bent valve right cus it was looked at right? hmm unless your o2 sensor was ****ed up and you were running rich and it melted your cat...maybe the IAC then. i would get it diagnosed somewhere possibly if your not getting youve done almost everything. it also could be warped pistons...

Yosshaa

Everything I have read is regards to ICAV talks about a screwed up idle... the car idles is fine in this case.

Yosshaa

I could be mistaken but I think the ICM is in the dizzy in these cars.
can anyone confirm that?

I've tried 3 dizzys! my old one, and two new ones (one from autozone one from checkers)

TheCivicMafia

How much ignition voltage are you getting and whats your fuel pressure?

it may appear to have good spark but it takes a certian amount of voltage to detonate on time.

And the iCM is replacable but its in the dizzy itself.

B16acivicsedan91

MY buddy had the same problem, running rich and the not reving past 3000, does it try to dies if you press the gas more then just a little?