Stumbling Accelaration, stalls too

[James Matteu]

I would however, manually test the entire ignition system for arc (cap, wires, coil etc.). It does sound like and ignition issue.

 

I have replaced the Spark Plugs, Ignition Coil, and Ignition Control Module; after the problem started. The Dist. Cap, Rotor, and Wires showed up today, I will replace those tomorrow. Essentially, my Ignition System will be new.

[James Matteu]

Can someone tell me what the ECU sensor reference is supposed to be at? I read 4.3V but think its been like this for a long time. Every test starts with lookin for that approx. 5V reference. Does approx mean 4.3 is okay, or does that mean anything between 4.6 and 5.4 is okay?

[James Matteu]

Update:

 

1. My ECU puts out the correct voltage, Radioshack meters suck and Fluke wins.

 

2. TPS gets 5v VCC and sends 4.5v at WOT to the ECU TPS pin.

 

3. I haven't used a timing light since 2000, so it is no surprise the ScanTool.net application shows my motor idling at 28° advance along with an overall negative short-term fuel trim. The advance is 13° over spec. and short-term fuel trim is probably a reflection of this. My C27A4 is OBD-II, so I cannot change the ignition timing, the ECU constantly adjusts this based on information received from the CKP sensor on my oil pump. When I was inspecting the CKP, the only thing I saw out of place was that the plug looked dirty. Of course, I will be cleaning this soon but feel that there must be another reason my ECU is running my motor all crappy.

 

HEEEELP!!

[James Matteu]

Replaced so far…

 

Oxygen Sensors: both changed; had Bosch, replaced with new Denso

 

Throttle Position Sensor: installed new Omni-Power B-series TPS; 5v VCC, calibrated with 4.5v at WOT

 

Distributor Cap: replaced with Honda OE

 

Distributor Ignition Rotor: replaced with Honda OE

 

Spark Plug Wires: replaced with Honda OE

 

Spark Plugs: replaced with NGK; gapped to 1.194mm

 

Ignition Control Module: replaced with used ICM from 6th Gen Accord

 

PGM-Fi Main Relay: replaced with used known working unit

 

 

 

It was suggested that I replace my 2 year old (OE style aftermarket brand: BWD) ignition coil, I will order this today.

 

I have a used ECU coming from eBay, I will swap it in and see what happens.

 

 

 

Here is what I got from the OBD data logger software:

 

At idle, transmission in Park, car up on stands, with A/C off…

 

 

Engine Speed (RPM): 755+45, s/b 750+50

 

Primary Oxygen Sensor: 0.115-0.895v, s/b 0.1-0.9v

 

Manifold Absolute Pressure: 4.35-4.495psi, s/b 3.44-4.91psi

 

Engine Coolant Temperature (ECT): 195.8-203° F, s/b 158-212° F

 

Loop Status: Closed, s/b Closed

 

Short Term Fuel Trim: 0% to -10.1563%, s/b +20%

 

Intake Air Temperature (IAT): as I ran the data logger, the IAT gradually climbed from 149° F to 156.2° F

 

Throttle Position Sensor: 14.11%, s/b 10%

 

Ignition Timing: 26.25+0.75°, s/b 15+2°

 

Calculated Load: 30.19-31.76%, s/b 24-34%

[Xeryon]

I have no help to offer other then moral support.

 

If you want a completely random support item: Our 98 i4 had a similar issue to yours. I spent considerable time troubleshooting only to have to take it to the Honda service center and end up paying $400 for them to replace a sensor in the transmission. Problem immediately resolved. No don't ask what the sensor was, that was 8 years ago - damn time flies.

[James Matteu]

Thanks, I'm just glad people are still reading.

[Xeryon]

have you checked something as simple as the speed sensor?

[James Matteu]

I haven't read the VSS VCC at key in ON, but the OBD-II data logger does get data from the ECU based on what is seen on the Orange wire coming from the VSS and it agrees with the Speedometer. I'll go ahead and manually check the VSS anyways; I'm not going anywhere anyways, and I've nothing better to do until the eBay ECU arrives.

 

Today's update...

 

I've had a productive yet frustrating day.

 

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).

[Turtlehead]

James, check your forum email.

[James Matteu]

I'm 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.

[Xeryon]

You should print this out so when the douche at the service counter tells you that it's your blinker fluid and it will be $479 you can show him your troubleshooting list and tell them you aren't agreeing to anything until they have absolutely confirmed that is what the issue is and have already tested the repair part in question. Otherwise, they may play that game of installing a part, and then requoting you when it doesn't work and installing more parts all the while leaving the first part in the car and billing you for crap you didn't need.

[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.

[James Matteu]

Thanks for everyone's help.

 

Good call 'Turtlehead', you said it sounded like an ignition issue and even in conversation said that if I suspect the ignition coil to change it rather than test it. Looking back over my testing, I found resistance across the secondary windings was 3 kilo-Ohms higher than spec back in July and I did not recognize the gravity of that measurement. Live and learn, slightly high resistance equals weak spark.

[Turtlehead]

Thanks for everyone's help.

 

Good call 'Turtlehead', you said it sounded like an ignition issue and even in conversation said that if I suspect the ignition coil to change it rather than test it. Looking back over my testing, I found resistance across the secondary windings was 3 kilo-Ohms higher than spec back in July and I did not recognize the gravity of that measurement. Live and learn, slightly high resistance equals weak spark.

 

 

I am happy for you man. I also did not realize how long this has been going on since it started in July. You sure went to school on this one... The timing could not have been better having bypassed the towing and Honda charges.