Distributor Problems - Stator Reluctor Gap

[pstone]

I really need some help on this one:

(89 Accord LX, Carb, AT, 196000 km)

My car has a really rough idle, when warm or cold. It's worse in gear, but it also does it in park. I know the rough idle is definately caused by a miss on cylinder 3.

This is what we have done:

- Checked timing and cleaned/gapped all plugs.
- Disconnected plug wires, one by one. This affected the idle on all cylinders except #3.
- Switched plug leads between #3 and #4, still missed on 3.
- Switched plugs between 3 and 4, still missed on 3. BTW, There was nothing visibly wrong with the plug from 3, same colour, no mechanical damage.
(Now we are getting really worried)
- Performed a compression test. All cylinders were even and within a good range (Can't remember the actual reading)
- Removed the valve cover and inspected the cam lobes, all the valves were opening and closing properly and the clearances were all within spec.
(So now we know there is nothing majorly wrong, like cracked head or bent valve)
-Went back to suspecting the distributor cap, removed it, ispected it, looked fine. Then is zapped the hell out of my girlfriend's dad after we put it back on.
(Aha, now we KNOW it's the cap leaking)
-Brought a new cap and rotor, idle/miss problem is still there. Plug lead removal test still points to cylinder 3.

So the question is: What else is there that can cause only cylinder 3 to miss?

If it was the ignitor, the coil, or something in the fuel system, wouldn't it affect ALL cylinders randomly?



Update: Replaced the PCV valve, the problem is a little better, but it didn't make a big difference.

[ghost_ny]

I had the same problem. So I said forget it. Now I'm doing a b16 swap

[A20A1]

Check the gap between the Stator and the Reluctor also known as the Air gap
Also check the blue and green wires running to the inside of the distributor since they might be corroded.
BTW I remember trying to pug in a loose spark plug wire while the car was running... for the life of me I couldn't let go... I kept convulsing everytime the wire would fire... finally my friend cut the engine off. it hurt like crazy but after I felt better I started to crack up on how stupid I was. :lol



here is a pic, the gap is fairly small so don't use the thickness of the yellow lines as a guide.
Both sides should have an equal air gap... sometimes the stator is kinked outwards... and if you look from top to bottom you'll see the gap at the top is different then the gap at the bottom.
Stator (not kinked) | Air gap | Reluctor | Air gap / Stator (kinked)
You must correct the kinked stator so that it runs parallel to the reluctor
Stator (not kinked) | Air gap | Reluctor | Air gap | Stator (not kinked)

[zero.counter]

I see that you have already checked some aspects of the electrical sub-system. Even the cam-shaft lobes, which would have been another of my suggestions. Here are some others.

Vacuum leakage, which we all dislike in some form or fashion, is notorious for rough idleling.

Clogged or blocked air filter elements can obviously restrict incoming air flow.

Fuel pumps start to giving out, usually choking the already starved CARB for fuel, possibly faulty.

Sometimes a leak can occur in an EGR valve, I would check that A.S.A.P.

And lastly and most serious, your timing belt and associated pulleys may be worn or need replacing.

Just some things you might want to look into.

[pstone]

Thanks for the advice. I will check the air gap....how big should the air gap be?

Also, how much free-play and is which direction is acceptable for the distributor.....I can turn mine about 10 degrees on the rotational axis, but there is very little (if any) bearing freeplay, lateral axis.

Checked the EGR valve, but it seems good. Timing belt and pulleys were still in perfect shape.

Wouldn't a fuel delivery problem like a bad pump affect all cylinders?

[A20A1]

Clean the threads inside the spark plug hole.

[pstone]

Cleaned the threads, still misses.

I finnaly broke down and went to a Honda dealer. They said it was the carb and it needed rebuilding....I don't believe them though; why would that show up as a miss on only one cylinder?

They said it is running lean, and I believe that, because my gas mileage has increased a lot since the problem started.

But I still haven't been able to get a believable reason as to why a gummed up carb would affect one cylinder (or appear to)....can anyone explain it to me?

I just don't want to spend time and money rebuilding the carb, only to find that the problem is still there.

[pstone]

So here's something else I noticed.....

Lately (Since the problem began), I have noticed that my car has been runnning hotter than usual. This is especially when the car is idling or coasting, but sometimes it does it all the time. It's wierd, and I can't quite figure out exactly when it does it, it's like random.

But the temp doesn't just stay hot...it fluctuates up and down a lot.

I have heard than a lean mixture will cause the engine to run hotter. Is this true, and could it be what's happening here?

Is there any way to test whether I'm running lean....I have heard of propane in the intake air, but I think that is to test for rich isn't it?

This problem is driving me nuts. I haven't even been able to find a mechanic that knows the problem. ARGG

[mindlos]

If your O2 sensor is still functional you can hook a voltmeter to it when the engine and exhaust are completely warmed up. The +ve lead goes to the sensor. The -ve lead goes to chasis ground. If the voltage is low then it is lean. If the voltage high then it is rich. The scale is 0V - 1V and stoich is about 0.45V. Bear in mind that it is not a linear scale.

[A20A1]

Check your coolant level... you might need to replace your thermostat... or even water pump. The sensor that gives the water temp guage it's signal is on the intake manifold, so that isn't the temperature of the coolant in the radiator or in the block. But it should be close.

[pstone]

Thanks guys,

I think I found the problem and we are going to try fix it tonight.

Sprayed some carb cleaner on the intake manifold right by the intake for #3 cylinder and the idle picked right back up. So it's either the gasket, or the manifold itself (which is unlikely)

I will keep you posted with the finding! But I think I finnaly got it figured now!

[pstone]

Problem solved! Busted intake manifold gasket right by cylinder #3. $5 Gasket....and a WHOLE afternoon's work to back off the manifold (It's a really bitch to get the bottom nuts off).

Flushed the coolant and changed the thermostat, so that fixed the high heat problem.

Thanks for the input guys!

Now it runs great again and I can sell it...any takers?

https://www.3geez.com/showthread.php?s=&threadid=22739

[Magny]

Originally posted by A20A1
BTW I remember trying to pug in a loose spark plug wire while the car was running... for the life of me I couldn't let go... I kept convulsing everytime the wire would fire... finally my friend cut the engine off. it hurt like crazy but after I felt better I started to crack up on how stupid I was. :lol

Dude I can honestly to god tell you that I know how you feel :lol. except my situation was different from that. All i wanna say is that i had almost 100k total volts zapped into me. highest alone was a 220v switch. aint telling anyome the story about it cause even though it was funny, i just dont wanna get dissed about it

[A20A1]

I've been zaped and temporarily paralyzed by house current... I was behind the family tv trying to plug in a double male ended plug... I was a total dumbass kid and plugged it into the wall socket first while the other end rested im my other hand... I was sitting on my legs and felt this sudden jolt that pulled my arm to one side while it forced my body into a ball... luckily the arm that was plugging the wire into the wall also contracted enough for the wire to fall out of the socket, no body knew i got shocked since i didn't let out a scream, they just figured i was messing around. I didn't go near that tv for a long time... in fact that night I didn't even watch the movie we rented I just went upstairs and stayed in my room.

[Magny]

ouch, ok I admit that you beat me on that one :lol damn that sux. mine only consisted of twitchin on the floor for about 30 mins

[keruhas184]

So I tried to get the gap right... At first on one side there was almost no gap. I backed out one screw and tried to set it right, but it still remained the same. Then I had to pull on other side of the stator to get to the other screw (that's what vacuum advance does - there is a lever that pulls on the stator), but after releasing that screw and adjusting the stator, now there is almost no gap on the other side and the reluctor slightly touches the stator (it originally did the same thing on the opposite side). I must say that adjusting this gap is a real pain in the ass and def. needs 2 people - one to pull back the stator, and the other to take care of the screws and the gap. I tried to set the correct gap, but it still remained scewed to one side.

But here's the thing - when you pull on the stator, that is, when vacuum advance kicks in, the gap seems perfect on both sides.... I don't know if this is how it should be or maybe it should be perfect when there is no advance? Also, the vac. advance lever that pulls the stator has some play in it that one must try to compensate for when adjusting the gap. Overall I'm still not sure if I set it correct. The engine still misses once in a while, but that can be any number of things.

[A20A1]

I usually don't do it the way the book says... unless it's really off... since my stator plates were blown away from the center I had to use a screw driver and clamping needle nose pliers that way I could set the gap and not need to loosen the screws... The stator base wasn't out of allignment anyways just the angle of the stator in relation to the reluctor.

Fixing the gap fixed my stalling at the light problem... and starting problem... If you ever had your car just shut down for no reason thats what to check. Though I'd have to say that I had other problems at the same time.

[keruhas184]

So you just jam the screwdriver and use the pliers to set the gap? I know I def. screwed up because now she shakes like a mofo...

[A20A1]

the screw driver I use to add leverage to the outside edge of the stator to push it in... the pliers help keep the stator facing at a 90 degree angle from the base.

My screw drivers have flat surfaces on the shaft not a rouns smooth shaft so it makes it easy to but it up against the edge of the stator plate and not have it slip off.