I bought a 98 Civic ex auto. The previous owner sold the car because of a horrible knock. While pulling the pan off to look at the damage (motor still in car) I noticed that all the torque converter bolts were loose. The torque converter would wiggle, which was the knocking sound. Put a new converter in because the bolts were breaking off. Also It looks like the tranny was changed, from a salvage yard, because the converter was a complete rust ball on the outside.

OK now the problem is that I am getting random, multiple and misfires on all cylinders. It starts to stumble at 1500-2000 rpm. If I slowly increase throttle it will rev on up fine. But quick throttle and normal acceleration has the stumble into the misfires. With car in gear the stumble is unavoidable.

Now I have changed the spark plugs, wires, cap and rotor, fuel filter, pump, injectors, and regulator. I am pretty sure both ignition and fuel systems can be deemed good.


I plan on checking the valve adjustments and cat converter next.

 

any cel?

 

could be your ignition coil. or bad fuel. try running some premium. is it a soft knock or a sharp sound

 

also pull your spark plugs. see if one of the spark plugs has more carbon build up than the others

 

Cel's are all 4 cylinder misfire, the random misfire/multiple misfire, and p1399. Don't remember the actual code numbers but that why I listed misfire. No other codes.

Was new fuel, forgot to mention I had checked the distributor, all was good.

 

They are new but will check. What would that signify?

 

MAP sensor maybe. Sounds like it only happens under load.

 

a bad cylinder.

 

check this thread out. might find a solution in here https://honda-tech.com/forums/acura-integra-type-r-8/misfire-problems-code-p1399-2694958/

 

The link really did not help. I have searched alot and most say the same stuff I have done or never say what fixed the problem

 

Was not the cat, map, or o2 sensor

 

Compression test and or leak down test

 

Why am i having a sneaky suspicion its the dizzy?
Seen this happen many times, culprit ended up being a bad dizzy.

 

Have you Ohm tested the coil and had the ICM tested by AutoZone?

Have you checked the mechanical timing?

 

have you checked to see if timing is correct? whatever it is its effecting all cylinders from the sounds of it. so its most likely not an injector. could be a fuel filter, a coil or possibly the ignitor... the first thing id check is timing tho.

 

Id check timing. Compression check, check fuel pressure off of the small fuel pressure access plug at the oulet of the fuel filter. if not check the dizzy it consists of 5 components, coil, ignitor, tdc sensor, cam sensor, and crank sensor... I could be wrong, but im pretty sure the last 3 will throw a cel. Both the coil and the ignitor are super easy to change and you can grab em from pretty well any dizzy for 92-00.

 

also, is firing order correct? 1342 clockwise around the cap

 

ok, the dizzy components are good, timing is good. compression was 165 to 180

I did a vavle adjustment and the hesitation/stubble greatly improved. the feeler guage was not the best to use though. I bought a new gauge and will redo the adjustment.

 

change those plug wires had a 93 ex to do this spent about 180 dollars on ignition parts when it turned out to be bad wires and they looked brand new not hard or anything no cracks i would change that b4 u did anything expensive a new coil is 70 and an icm is 85 at advance auto for oem parts

 

P1399 = problem in the firing system. Replace your plugs, wires, cap, and rotor. If that doesn't solve the problem, replace the distributor with a new or known working unit. Yes, I realize it's passed all of your tests, but that doesn't mean it can't have a problem. Half the time you see a P1399, the dizzy passes all tests, but replacing it still fixes the problem.

 

i had a multiple misfire code and couldn't figure it out for a long while until it poped up a MAP sensor code. I swapped it out with a known working one and haven't had a problem since.

 

I 2nd the MAP sensor (manifold absolute pressure) because the stumble happens on higher load/vacuum shifts (more extreme throttle variations - pulling in gear vs. neutral). It sends data to the ECU to help determine your fuel metering so that could cause misfires. Kind of reminds me of trying to ride a motorcycle with clogged jets, how the bad fuel mixture makes it stumble and run like crap.

Also, you might want to check the crank sensor down by the lower timing belt gear to make sure its not coming loose. That would involve removing the crank pulley and lower timing cover though. Hex pulley holding tool required (45mm?). It is a little sensor that is mounted with a 10mm bolt and pin but the mounting is plastic.

At least thats how it was on the 98 EX I just replaced the T-belt and pan gasket on...

Are we talking a D16Y8?

 

yes it is a Y8

I ordered a new distributor. The only checks that can't be done that i think could be the problem are the magnetic pickups down in the dizzy. since they are not replaceable then would be a good assumption. If it is not the problem I still needed a dizzy for another motor I have

as for the MAP sensor, I unplugged it while running and the same stubble happened, even with the increased rpm of the MAP being unplugged.

I have swapped out the wires with many other wires with still no change

Did a second vavlve adjustment with a better feeler guage. Helped how the motor sounds but did not change the stumble

 

Swap MAP sensors from the other car?

 

This ^


Kinda just skimmed through this thread. Checked timing? Color smoke coming out of exhaust?