mgags7

Guys all I want to see is people that had random misfire CELs and what you did to fix them.

F*ck this code!

vinuneuro

Matt, my cel's started coming after I dumped a ton of seafoam in the egr valve port. After that I changed the plugs and did a valve adjustment, but still got them. The misfire codes stopped when I started exclusively using Shell V-Power gas. No joke. It has helped mileage too.

577HondaPrelude

I had it last year when I started the car up with 6 month old gas. The car sat all winter. I put some fresh new gas 93 octane and it went away. Maybe you got a bad batch of gas? Also make sure your ECU has a good ground connection.

mgags7

Its done it with a lot of different tanks of gas, so I don't think that is the problem.

The ecu has zero ohms to ground, but the battery is in the trunk. Do you guys think the distance from the ecu ground to the ground wire has anything to do with it?

My EE senses tell me the only real consideration there would be resistance thru the chassis, but that should be minimal.

mgags7

bump for help

Ransom

Mine was slightly bent valves

mgags7

did you have low compression with them?

DCxMagus

last time I got random misfires it was my distributor going out, the problem went away when I used octane booster as I only got the code when I was in high RPM's.

I swaped plugs wires and rotor and cap and haven't seen it since.

Ransom

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mgags7 &raquo;</TD></TR><TR><TD CLASS="quote">did you have low compression with them?</TD></TR></TABLE>

Yup, cylinder 1 was about 30 psi lower than the rest.

ziptie

got a new distributor and never looked back

mgags7

Ok cool thanks for the info, I'm checking all my connections today and swapping distributors with my brother to see if that does it.

dagle

iTrader: (1)

ran into this on a google search:

http://www.aa1car.com/random-misfire/

A random misfire code can be set on newer vehicles with OBD II onboard diagnostics when multiple misfires occur randomly in multiple cylinders. The cause is typically a vacuum leak in the intake manifold, throttle body or vacuum plumbing, a defective Exhaust Gas Recirculation (EGR) valve that is leaking exhaust into the intake manifold, or even bad gasoline. Less common causes include bad spark plug wires, worn or fouled spark plugs, a weak ignition coil, dirty fuel injectors, low fuel pressure, or weak valve springs. If a misfire is occuring in only one or two cylinders, you will usually find a misfire code for that specific cylinder rather than a random misfire code.

from what i read, its only for OBDII, and from seeing ur FS thread u have the rare 96OBDII ecu. does it give the code on an OBDI ECU?

good luck

mgags7

thanks for the info, most of that stuff, unfortunately, has already been checked and is fine. The IM gasket could potentially be leaking, but I somewhat doubt that because the car usually drives fine.

OBD1 does not have this code, only OBD2.

dagle

iTrader: (1)

hmm, well approach this the trial and error way. i vote super high octane race gas or E85 in the said conditions that would trigger it and see if there's a difference, and re-check everything one last time before committing to the OBDII motor stuff. =/ if its really the charge duration thing said in the other thread.. well, i know a couple guys that have wrecked ludes with good fronts for the OBDII stuff

mgags7

believe me dude, there is plenty of trial and error going on

anyways, I'm not converting to the obd2 stuff, if it comes down to it and I can't figure it out I'm selling it to the guy as is. there is no driveability problem just the gay code. whatever.

DCxMagus

mgags7 have you tried running a bottle of octane booster through it?

when I first started seeing that code, if I ran a bottle of that outlaw stuff in the tank I never saw the light, any tank I didn't the CEL would come on.

Obliviously this is only masking the problem, as the CEL would come on and eventally I got 4 misfire codes(one form each cylinder) before I replaced the cap, rotor,wires, and plugs to finally fix the problem.

when I first started getting the code it only would come on after a high RPM run, then later it come on during cruising.

mgags7

This problem is a little different. I believe it is due to a bad distributor, it has been slowly failing over the past few weeks due to an overlooked open in a wire from some time ago. I'm about to replace it, and I think that will take care of the code.

I'll be back with some results soon Thanks again for the help guys

honda_nation

My 98 CR-V was misfiring very randomly. It ended up being a wire that goes to an injector.

mltv

same thing here my problem was the spark plug wires, not a problem since the change

PrittyPearllude

So my CEL came on and read the misfire in cylinder 1 this weekend. I had the code cleared and it hasnt come on since...

Based on the post it looks like I could have gotten some bad gas somewhere or a ground in the ECU isn't good??


Modified by PrittyPearllude at 9:05 AM 2/12/2008

preludeSRV

I heard converting to an OBD1 will solve the problem of the misfire. This only works if you car runs fine when the light is off.

Ransom

Have you tried a new coil? My buddy's 5th gen would throw this code and miss at idle. New coil and a valve adjustment, runs like a champ.

Jaudette

i like to think of myself as a bit of a thread grave robber, raising them from the dead and such, but i just dont like starting new threads for one question

anyways, ive recently converted my 90 crx to obd1, im running 750cc with a garret .50 trim and a moates demon with neptune rtp.

im getting code 8, tdc sensor, i played with the dizzy rotating it back and forth, no luck, i also advanced my ignition a bit which helped but didnt solve the problem. after double checking my wiring from the new distributr right to the obd1 pins ive confirmed that it is correct, does anyone know what else could trip this code?

thanks