1998 CIVIC LX 200,000 Miles (everything OEM Original)

code 73 (misfire cylinder 3) about a month ago, new plugs/wires, code went away

car started bucking violently when accelerating or going up hill even slightly ,only on startup, would go away after 10/15 minutes after heating up

code 73 again today, new distributor(cap looked real black on #3) rotor, fuel filter, (also cut open the filter with a sawzall and there was all kinda grit in there) but now throwing codes 71 72 73
bucking went down dramatically but can still feel a slight tug/buck, went away after 1/2 hour driving moderate speeds 30-50mph

wondering if no cap/rotor for 200k wore down the coil and made it weak now its misfiring because the rest of the components are new...

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If it matters, I was overheating last week, put new thermostat, rad cap, ran a pressure test and it stayed consistent for quite awhile which leads me to believe its a plugged or blocked radiator, since Ive never flushed it in 200k, and it only happens when im idling, when driving, cools right off to normal temps.Also fan comes on no problem.
Also did an oil change and the oil looks fine so can rule out any blown gasket leaking coolant...

Or is the misfire timing somehow connected to a bad water pump which is causing both issues somehow? Low idle , no coolant flow, weak pump messing up the belt, or backed up radiator somehow messing up the pump which in turns makes the timing bad. Or am I on the wrong track here...
Last timing belt was at 100k along with a new pump.

 

Resistance test the coil.

If it's fine, compression test the cylinders.

 

Finding no water in the oil does not "rule out" a bad head gasket. Slow leaks don't do anything but lose coolant, eventually leading to overheating. Does the radiator stay full? (Check it when cold before starting, check in the radiator not just the plastic tank). Does the heater work?

For the misfiring if you used aftermarket wires they may need replacing again. Some of them are really lousy. Use OEM wires instead.

 

Checked the coil and it looked fine, then when test driving it didn't even make it out of the driveway , so rechecked it and found out the secondary was about 3k ohms under minimum specs, thanks to your diagram I found on another site RonJ How to test ICM and Coil? - ClubCivic.com - Honda Civic Forum. Comparison of a new coil confirmed it was bad. Took it home put it in , fired right up, reset codes by uncorking the neg battery terminal. However the number three plug was looking pretty nasty even after a few weeks , had a reddish top and charred threads kinda. Will probably replace that NGK V-Power.

Did a compression test on the cylinders, read 90psi across the board. Not sure what factory specs are on a D16 but 90 all over looks good to me, maybe stock is 110? So prolly has lower compression but no leaks far as I can tell.

Then the over heating issue: realized I hadn't run the heater while burping the radiator for air pockets(thank you dad) That probably caused a small loss over time from the air in the system allowing it to evaporate. Sure enough, heated the car with the rad cap off and turned on the heater and bubbles were popping out all over the place.

So far so good, 200k down 200 togo!

Thanks for your help guys

 

90 is a little low, I believe.

 

I can't find that info anywhere, I was just happy it was consistent on all 4 cylinders. Any idea where I can find the specs? Thanks

 

+1

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You might try putting a can of this product called "Restore" in your engine. It goes right into the crankcase with the oil and after around 200 miles, it is able to fill in some of the scoring on the walls of the cylinders and restore compression.

Restore USA - Engine Restorer Test Data

 

Right on, I used to use that when I ran V8 Monte Carlos, was thinking about adding a can, couldn't hurt. Still can't find any info on stock cylinder psi 98 D16.

 

It's important to know details about how you did the compression test prior to concluding that you have low cylinder compression. Look up Forty04's DIY. For example, was the engine warm or cold? Was the test done at WOT?