Stumbling Accelaration, stalls too.

[benjiaccord]

I'm just going out on a limb here, but could your timing belt have slipped a couple of teeth? 28 degrees is a hell of a lot!

[James Matteu]

I'll check the timing belt tomorrow. I read somewhere that a loose belt could do the same thing. I'll go ahead and pull the covers off to have a look at the timing marks before going through the tightening procedure.

And my thoughts exactly, 26° is alot!

[benjiaccord]

My thoughts exactly...yeah, a loose belt can slip...or if your belt is worn, its possible to lose a few ribs in it. However, if it does happen to be the problem...at least you'll have damn near a new motor in that thing!! You've replaced about every thing I could possibly think of

[James Matteu]

The timing belt has always been changed when the maintenance interval has come around, so I know the one on it now is not old and should not be worn (yet to be seen). What has not been changed since I've owned this car is the Water Pump and Timing Belt Tensioner. I've had it since '02 and the first TBelt change was done at Honda; I told them to only change the belt, so they never touched the Water Pump or Tensioner. I changed it last time and didn't change the Water Pump or Tensioner. I was going to wait until the next interval to get at the Water Pump and Tensioner. I've removed the Timing Belt while working on oil leaks last year and never had a problem with the Tensioner. We'll see tomorrow.

[James Matteu]

Update...

Today has been productive, but frustrating.

I checked the timing belt position; all three* marks were spot on. *C27A4: front cam green, rear cam white, crank pulley notched.

I cleaned the CKP connector with brake cleaner and after it was dry reconnected it. There was no change in the problem.

Here is the frustrating part:
I pulled the timing light back out. This time I used some chalk to high light the timing marks; last time I did it at dusk so the marks would be more prominent, but still found myself straining to see them. Here's the rub, the timing's right on 13° BTDC. That's good considering timing s/b 13-17° with engine warm, at idle, with A/C off, and SCS connected. So I wondered why the OBD-II data logger consistently tells me it is about 26°. I turned the dial on my timing light to 26.5° and found the TDC mark aligned perfectly with the pointer mounted on my timing belt cover...

So, the OBD-II data logger reads ignition advance in terms of degrees TDC, but Helm specs are in terms of degrees BTDC; a simple oversight on my part.

Right now, I am out of ideas short of a new ignition coil and swapping in a different ECU (ordered and on its way).

[benjiaccord]

In these regards, I would think that a bad coil would show at idle as well as under acceleration. But who knows...when it comes down to electrical like that, it could be any type of problem. Lets hope its just the ecu.

[James Matteu]

Throwing in the towel

I swapped the ECU for the eBay one and there was not only no improvement in the issue, but the car continued to act exactly the same. I figure the likelihood of two completely different ECUs behaving in exactly the same way is so infinitesimal that the problem must lie outside the ECU. Furthermore, if both ECUs are functioning correctly, and neither store error codes for a failure in the MAP, TP*, HO2*, ECT**, CKP, CYP, TDC, EGR Lift, or IAT sensor then I should be able to assume that not only are none of the sensors faulty, but their connection with the ECU is good; *new, **2yo. Not to mention I spend a good deal of time checking the sensor array’s wiring harness for open or shorted circuits.

Ignoring the ECU and senor array doesn’t make sense to me either since the Fuel System and Ignition Systems seem to be okay…

On the low-side of the Fuel Filter, fuel pressure is mid-30s with regulator and high-40s without. I ran a can of BG 44K in the fuel today and there was no change in the problem. That product is sold as an injector, intake, and valve cleaner; according to the MSDS, it is a mix of mineral spirits, petrol light-ends, and light petrol cyclic hydrocarbons. The BG 44K fuel system cleaner is supposed to eliminate clogged or stuck injector valves as a possibility, but I do not have the tools to monitor injector duration though I have checked the resistance on both the injectors and the resistor box; both checked out okay.

I rebuilt the distributor, which isn’t saying much since the V6 only has the ICM in it; the CKP, CYP, and TDC sensor are mounted to the oil pump and front head, respectively. I put on new cap, rotor, wires, and plugs; just to be sure. The coil (BWD) checked out, and the ECU’s tachometer signal is consistent with the dash gauge cluster.

I ordered a new Fuel Filter and Ignition Coil (TEC) but they haven’t arrived yet. I’m not waiting for them to arrive, I’m done, I’m tired. I started with the ECU, checked, double checked, and triple checked the: ECU, fuel, and ignition systems; only to find myself looking back at the ECU. I’m going in circles with this. I want Honda to tell me what is wrong so I can fix it and be done with it.


Thanks for everyone’s help. It gets towed tomorrow, I’ll let you know what Honda finds.

[benjiaccord]

Wow...I will say this. You are thorough. By now, most guys on here, including me. Would have ordered a new motor or dumped the car off. I love my car, but with all of that checking and rechecking, I'd be insane by now. Hope they find something and its something easy for you. Nobody who goes through all of this trouble should have to deal with that.

[James Matteu]

I Fixed It!!

At about 11am, right as I finished prepping the car to be towed to Honda, the FedEx truck arrived with my OE Honda Fuel Filter and OE TEC Ignition Coil. I looked at my car and said, “The governor called, you get to stay alittle while longer.” I had a service appointment with Tom at Duval Honda for after-4pm, the tow truck was going to be at my house by 3:30pm; so I had some time.

I put in the new Fuel Filter, no change, problem didn’t go away.

I put in the new Ignition Coil, bam! No more problem.

A word to the wise, add BWD to that list of brands that suck on Hondas (like Bosch Oxygen Sensors). That BWD Ignition Coil failed after 27 months of service; a complete piece of junk in my opinion.

[benjiaccord]

Wow......all that and it was the ignition coil. Makes me want to switch over to MSD and call it a day!!

Glad you got it fixed man, really glad It baffles me that it was the coil, but hey, now you know everything on your car works!!!

[James Matteu]

I read that an Ignition Coil can test okay when cold but then the resistance sky-rockets while in operation. That was obviously the case with me as the resistance checked out when I tested the BWD coil over and over (cold). Why the 4-cylinder coil didn't work when I swapped it in place of the BWD is something I don't understand but have speculated that either that 4-cylinder coil was bad too or unable to support the demands of my V6's firing sequence. What really gets me is that the BWD was only 27 months old; live and learn.

[TomQuick]

OEM FTW!

Congrats on sticking with it, and getting it fixed!

[HondaFan81]

Congrats, definitely respect you for your effort and very detailed right up.

Please write a short summary of your findings and include in link below: Problems: Symptoms & Diagnosis Log sticky. Follow the format, which include vehicle information.

Thank you.

http://www.cb7tuner.com/vbb/showthre...t=19666&page=4

[James Matteu]

Done.

Accord Vehicle Info:
1997 Honda Accord EX-V6, applicable to all C27 powered Honda/Acura vehicles: 1995-97 Honda Accord V6 models, 1987-90 Acura Legend 2.7L models

Symptom(s):
Car shuts off and/or runs-poorly/hesitates/stumbles, especially under acceleration; occasion backfiring during hesitation/stumbling. No power loss, no irregular speedometer/tachometer function, possible damage to Heated Oxygen Sensors and/or Catalytic Converter due to hesitation (can be mistaken for a cause, rather than a symptom), no blown fuses, and no low fuel pressure.

Cause(s):
Weak ignition coil

Price(s):
Honda OEM (made by TEC) Ignition Coil $89.01 plus S&H from Majestic Honda

Solution:
Replace ignition coil