230 misfire

[Matthew Ziegler]

I took the m37 for a spin today, idling a little rough, sounds like 1 dead cylinder when trying to accelerate. once up to speed in fourth gear the truck runs good. I loosened the plug wires, started the truck and checked each cylinder by removing and replacing the wire. Number two doesn't seem to be firing all the time, I pulled the plug and it's clean, not fouled or wet, I'm thinking distributor cap. The distributor was checked out 3 years ago, bushings are within spec, evrything was cleaned up, lubricated and petronix electronic ign. installed I also removed the filter or capacitor from the power lead going into the distributor the plugs are 2 or 3 years old and I got a set of new replacement plug wires when I replaced the distributor. anyone have any suggestions? I don't know the age of the coil, I think it's a spare from a m715, age and mileage unknown.

[maineSS]

Bear in mind that amperage, not voltage, is the important factor in firing the cylinder. If you have a weak coil, excessive gaps between the rotor and distributor tower, or at the plug, or resistance of the wire or at its connections could produce this problem. Another thing to check is compression in the affected cylinder, you may have a valve sealing problem.

[Matthew Ziegler]

I'm going to do a compression test, have to borrow tester from my buddy, just seems strange that it was running fine a few days ago. The guy who put my cam in wasn't as meticulous as I would've liked him to be, wondering if he left something loose in the valve adjustment.

[Cheyenne Dave]

I'm going to do a compression test, have to borrow tester from my buddy, just seems strange that it was running fine a few days ago. The guy who put my cam in wasn't as meticulous as I would've liked him to be, wondering if he left something loose in the valve adjustment.

Matt, anything that loose in the valve train and you'll be hearing something pretty clattery!

CD

[Matthew Ziegler]

valvetrain

I guess it's not that...runs like a guy on crutches on acceleration no metal on metal or anything like that. haven't gotten around to doing the compression test, been working for a roofer friend for the last couple of days

[Kaiser2boy]

The Coil or capacitor would not cause just the number two cylinder to misfire. A bad wire , yes, a bad valve yes, a stuck ring yes.
Getting at the valve adjustments is a lot of fun, good luck with that. Just wondering if the new cam was one of those spray welded deals. If so you may have a lobe that failed.

If your compression is down the next step will be to try and find out if its a bad lobe by watching the lifters on that cylinder and turn the engine to see if they both go up and down the same amount. If the valves seem to be OK squirt some oil in the cylinder and retest the compression , if it comes up you have a bad ring if not its probably a valve problem. Either way it wont be fun.

[Matthew Ziegler]

fixed

cap and rotor were bad, contacts looked kinda burnt, switched it out for a new cap i had on the shelf and a new rotor from memphis. there was also a lot of oil in under the coil, I'm guessing this was spilled when the filter was drained during the cam install, anyway, cleaned it all out very thoroughly, can't see any place that oil could come from, buttoned it back up and the truck is running great. While I was at it I changed the cover screws on the distributor to socket head allen screws, much easier to service than the original slotted head screws, especially if you have a set of allens with the ball at one end.

[Kaiser2boy]

Lucky it was not the valve thing right. As I recall there is an oil cup on the distributer that should get a few drops of oil when you change your oil.
Maybe some one got carried away with that task. Once oil gets in there there is hardly any place for it to go.

I know what you mean about getting at the dist. It is not in a very good spot.

[Charles Talbert]

M715 coil???

The original M715 coil requires a ballast resistor be used. It is a thin wafer with 2 leads that fits under the coil in the housing. If you are using a genuine M715 coil, it won't last long without the resistor in place.

Oil in the housing generally is there as a result of a failed distributor upper shaft oil seal. This is just above the top shaft bushing; and seals out oil from the upper cavity. Worn bushings letting the shaft run off center is a major killer for this seal. It is a relatively light duty seal and will not stand a lot of abuse before failing. Another major cause of seal failure is a lack of lubrication at the top bushing area. The upper bushing does not oil from the engine; but has to be oiled manually through the elbow. The elbow plug should be removed at regular intervals to fill the elbow with engine oil. This is most often done at oil change intervals. The slow release oil supply to the upper shaft bushing is via an oil wick that rubs against the shaft as it rotates.

This system works flawlessly if it is maintained correctly; but if it isn't will go down in effectiveness quickly. Many owners are not aware of the manual oiling necessary at the distributor or the generator front bearing. These are the 2 points that usually get neglected, and are major trouble issues.

[Matthew Ziegler]

distributor

I'll check that oil seal, the bushings are ok, checked them when I changed the distributor a few years ago, there was no detectable side to side play, I found this distributor laying in another m37 in a local junkyard, it was nice enough that I suspect it may have been n.o.s and junked with the truck. I'm only guessing on the coil, dad had a lot of m151 and m715 parts laying around. Would you have the part number or could I purchase a seal from you? Also, I did add the elbow for oiling when I installed the distributor, mine had a small plug, didn't know about oiling the generator, I'll have to look at that. I've been adding a few drops of 15w40 to the distributor several times a year, is that what you'd recommend for the generator?

[Charles Talbert]

I'll check that oil seal, the bushings are ok, checked them when I changed the distributor a few years ago, there was no detectable side to side play, I found this distributor laying in another m37 in a local junkyard, it was nice enough that I suspect it may have been n.o.s and junked with the truck. I'm only guessing on the coil, dad had a lot of m151 and m715 parts laying around. Would you have the part number or could I purchase a seal from you? Also, I did add the elbow for oiling when I installed the distributor, mine had a small plug, didn't know about oiling the generator, I'll have to look at that. I've been adding a few drops of 15w40 to the distributor several times a year, is that what you'd recommend for the generator?

The older style generators found on most M37's have a small reservoir in the front cover. The fill plug is on the cover directly beneath the shaft belt pulley. If there is no plug, then you have the later style that used a sealed bearing and has no reservoir. Oil should be to the point of over flow at the plug opening.

Yes we stock the distributor oil seals.