Jet Black

Well I'm all out of ideas, so I'll bow to a higher intellect.


Syptoms:
Hard jerks from an apparent missfire...feels exactly as a car does when it sputtering from lack of fuel. Happens under light load, in low gears (esp right at a shift to 2nd), similar hard jerks can be felt at idle...almost like an AC comrpessor comming on (no AC on my car). There seems to be no correlation for time or cause...I might drive 10 minutes with nothing or get 3 in 30 seconds.

First thought was a lack of fuel. So I've hit the gas hard after a misfire like that...felt completely fine. Also, if there is a misfire at highway speeds, where a hell of a lot more fuel would be required, it can't be felt. I drove it 100K on the hwy today, never felt a jerk once.

I considered a bad connection so I jiggled each connector at idle yesterday with no symptoms appearing.

I thought of a sticky injector, so I listened to each one, they are clicking away (however, I never listened to them during a misfire since it's so random)

I've poured 1L of water on the ignition wires while running, no change in engine speed.

I've swapped out the ICM and coil, cleaned the points on the distro, retimed the engine and checked spark. It's a nice blue color.

I've taken the TB apart and cleaned out the IACV and TB using some carb cleaner. They were nice and clean, but I figured I'd give it a go anyways.

Idle speed seems steady at 750, but sometimes after one of those jerks it drops to about 600 and sticks there for a while.

Things seem worse once the car is warmed up....but again, never noticeable on the highway.

I doubt it's spark since I'd expect a series of misfires and not only one, plus most of the important components were changed.

I doubt it's fuel since it's not apparent under heavier load where fuel requirements are more important. It might be the TPS, but I'd expect the problem to appear at the same throttle position all the time.

This leaves me with air. Which makes sense if it's less apparent at high speed (sure the lack of torque from a misfire would be less noticeable at in a high gear....but I don't know...it feels fine on the highway). So it's MAP or IACV. I'd assume MAP would either work or fail since it's just a barometer.

So...I'm thinking IACV....scary thing is jerks seem less apparent at idle than during driving.

Side note which may or may not be important: I sometimes hear a high pitched whine (a bit like a bad bearing, but it's not loud at all) near the back of the engine. It could be the alt, but the unit I have is only 7 months old. It almost sounds like the whine is located in the TB.

Jet Black

ttt

Former User

How old are the plugs, wires, cap, and rotor? And spark at the plugs should be bright white not blue. If it's blue, the new coil may be bad.

Any CEL codes?

Jet Black

Thanks for the input.

Plugs have about 6000K on them. Cap, rotor,wires are about 2 years old, but seem in pretty good shape. (pass the water bottle test and fuel mileage is fairly normal)

I thought a bad coil was a yellow spark, bright blue being normal?

No CEL codes, I would have checked those first.

Former User

Inspect the plugs, cap, and rotor, and resistance test the wires. The water test only reveals certain types of faults in the cap and wires.

Spark at all four plugs should be bright white with only a very faint hint of blue. This faint blue is often difficult to see, especially in daylight. Orange or deep blue spark is a problem.

Jet Black

I'll check the wires tomorrow...in the mean time more symptoms showed up tongiht.

I drove it for 1 hour no problem, but right after getting off the highway at a light the idle got all messed up. It was vibrating hard and stuck pretty low. I seem to remember the tach was registering 1100rpm but it felt lower...then it droped to 600. (I was kinda tired at this point, so I'm not 100% on the rpms being off). I gave it a few blips of gas when it felt like the car was about to die, rpms went up with a lot of vibration and an emptyish popping sound comming from the engine...then suddenly everything went back to normal.

I can't get it to do it again...but this leads me to think I have one or possibly two cylinders missfiring. I can't see how it would be spark related...since it would be odd as hell for it to constantly miss only one or 2 cylinders...after the fact I wiggled all the ignition wires with no effect.

I'm thinking I might have a lazy injector. I'll know more tomorrow, but after checking the plugs, I'll pull the wire to an injector to see if the effects are similar.

Jet Black

Pulled the plugs, they look decent...more or less brownish...a lot of black on the electrode, but then, the car had been idling for a while prior.

Pulled the fuel injectors, there was a fair bit of carbon on the nub (not on the end itself though), cleaned them with some carb cleaner.

Tried to see how it ran without one cylinder, didn't feel as bad as last night.

Drove it home and it happened again...but this time for much longer. I had the time to pull over and see which cylinder was the culprit. I pulled the wire to each cylinder in sequence. Cylinders 1 and 4 didn't seem to have any effect on the engine once the wire was pulled.

So maybe 2 cylinders are dying? I then blipped the gas a few times and everthing came back to normal.

Will try a compression test tonight, but I doubt that will tell me anything odd, since the problem is intermittent.

Jet Black

Compression came in at 208 214 218 212 (1,2,3,4)

So compression is decent. I checked the spark, and it's a purple blue for all cylinders. I know RonJ@HT mentionned a white spark, but I thought high energy sparks were blue purple in air due to nitrogen being the predominant gas in air.

http://www.periodictable.ru/007N/slides/N2.jpg

I swapped the spark plug wires to another set. Same problem.

I ran an OBD2 scan on the TPS and it operates within spec. The MAP sensor registers a proper value too (at least at idle....can't test above idle since it's not in the shop manual)

GSR-C5

I have a 99' HX that is doing the same thing as your car, but I'm getting a P1399, P0303 CEL and today for the first time in 2 weeks I got a P1491 EGR cel, unpluged it and plug it back and the codes is gone.

I have changed the Plugs, wires, Rotor, Cap, Coil and clean the injector, ran injector cleaner, fuel system clean and now running 93 octane gas and new fuel filter. Still having the same problem as you. Is your hesitating/splutting are 1K-2K RPMS?

I will check my timing tomorrow.

Jet Black

Well, i've had the idle drop to like 500 with significant vibration, but sometimes the car has a momentairy lack of power...that can be between 1K and 4K...incidentally that's where it normally operates for me...so no clue if it happens between 5 and 6...I'd assume so.

Jet Black

Found the problem!!!

Somehow the end of the camshaft shattered. The rotor shaft could wabble about 5 deg messing up timing.

vwtohonda

Wow, I would have never checked something like that , good find, but unfortunate... You can geta better one now

vwtohonda

93 octane will not help you car at all... run 87... Search if you have questions.

TUNE ACCORD

EVERYTHING THAT WENT WRONG WITH JET BLACKS RIDE IS HAPPENING TO MINE EXACTLY TO THE 'T'. BEEN UNDER THE HOOD ADJUSTING FOR WEEKS AND STILL ITS A 'NO GO', BUT I WILL TAKE A LOOK AT THAT CAMSHAFT AFTER THIS STORM LEAVES FROM ABOVE.

WISH U ALL SAFE TRAVELS

96 ACCORD......LX......2.2MFI.......NON VTECH

TUNE ACCORD

JET BLACK, IF POSSIBLE, COULD YOU RESPOND TO ME VIA THIS FORUM AND LET ME KNOW THE UPDATE OF YOUR RIDE AND HOW ITS HANDLING AFTER FIXING THAT.

APPRECIATED

Former User

Please turn off the caps lock.

Consider making your own thread as this one is more than two years old.

ohsnapzafingcu

iTrader: (2)

I had something similar happen, i also changed out the ICM and coil and i still had the same problem. it was just a bad dizzy. i changed out to a new one and car ran fantastic. see if you can swap in a spare dizzy from a running car

Former User

If you have a spare distributor laying around, this^ is a reasonable test.

However, I think that the general approach of throwing parts at problems is a poor approach to fixing car problems. I would do this forum a disservice by saying otherwise. Instead, perform diagnostic tests to pinpoint problems. Such tests are clearly described in the service manual and many diagrams also can be found in the FAQs sticky.