azazel_18_2

I have a 98 civic dx with 150k miles. Engine was rebuilt at 100k miles as was timing belt. One day I started the car and p1399 came up with all the cylinder misfire codes as well. Started with the usual. Cap, wires, rotor, and iridium ngk plugs. Still same old crap. Changed the oxygen sensors. Still same crap. Checked vacuum leaks. None. Checked valve lash. Perfect. Checked compression. 185 across the board. Last but not least I bought a distributor from napa. Same crap. changed fuel filter and checked pressure and it was good. Pulled injectors and they were very clean. Ran cleaner through the system. Just tired of it. Some days it will run perfect with no check engine light and some days it runs like crap. It coughs and sputters only below three thousand rpm. Any ideas? This thing is driving me nuts!!!

go-part

Well this is a compression issue, since you get fuel and spark.

You should check your crank and cam position sensors next.

azazel_18_2

Cam sensor is I the distributor so it should be new. haven't touched the crank sensor. Called oriellys and they say it could be an 18 or 20mm diameter sensor and both will have to few ordered. Any way to check these sensors?

ezone

Since the problem is easily duplicated, it should be easy to diagnose for someone that knows what they are doing.


You got a P1399, what is the Freeze Frame data that goes with the code?

You might disable the EGR valve and see if that makes a difference.

azazel_18_2

What I have found. Tore car down and found crank sensor wires frayed. Also found timing belt very very loose. Had it done thirty thousand miles ago!! Ordered a timing kit and crank sensor. I'll get it done tonight and post my results.

ezone

Oh good eye!

The wires have been rubbing the alternator belt? I bet whomever did the timing belt didn't tuck the wire loom into the holders on the edge of the timing cover.

I also have a feeling that although the rubbed wires can cause the P1399 code, that alone (wires rubbed) won't make it run badly. Fix it and see. Hope it takes care of it. Good luck.

azazel_18_2

Well the nightmare continues. Got everything changed out and still code p1399. I'm going to break out the volt meter and check my new napa distributor. Not sure where else to go with this thing. Driving me nuts. I smell fuel at an idle but fuel pressure at idle is 39. Not firing right.

azazel_18_2

Swapped the distributor off my brothers car and still the same misfire. Not sure where else to go with this thing. Drinking the gas. Fuel pressure is at idle 38 and with gas pedal pissed I get 45. I have an aftermarket fuel pressure gauge on my fuel filter for my readings. So ticked I'm about to drive this thing off a cliff! Checked compression again with new timing belt and now I get 195psi across the board. Old belt was off one tooth. I got it set perfect. Checked it a dozen times literally. Checked valve lash again. .008 on intake and .010 on exhaust. Only a few things on the dang engine I have not replaced and that would be tps and fuel pressure regulator. One last weird thing. When it does run good it will start misfiring only when going up a hill. Start down it and nothing. Get on it hard nothing. Just has me scratching my head.

ezone

Have you driven the car with the EGR valve disabled yet?

azazel_18_2

Its a dx so it does not have an egr valve

azazel_18_2

Scratching my head really bad. Just about everything has been replaced. Ordered new injectors and pressure regulator. Before all is said and done I'll have a new engine. Lol

TLGriff

I've had similar issues with my Si over the last couple of years and like you, am beginning to look for that cliff. One thing I did that helped, but didn't completely cure the random misfire thing was change the plugs on the injectors. I found that by wiggling the plugs I could get it to misfire, so they had apparently worn out after 230K miles. It helped some, but still the problem continues so obviously there is more than one issue causing it. I've replaced the plugs with the OEM platinum Denso's, the plug wires, cap, rotor, coil, ignition module, injectors and injector connectors. I was thinking of replacing the entire distributor next in case there is some wear inside from the high mileage, but it doesn't sound like it helped in your case.

I know this thread is a few months old, but did you ever get it figured out?

Tom