Hows it going? I recently picked up a 92 VX with 250k on it. Had a check engine light that would pop on randomly after purchase and a slight hesitation on acceleration every once in a while. Needless to say after beating on it for a bit it has become a problem.

Sputtering/hesitation starts at 1200rpm and goes until 24-2500rpm then car resumes normal acceleration. During that hesitation there is no power under load/throttle. Barely give it throttle and it can work through it.

Felt like ignition issue, so replaced cap/rotor first...drove fine for a couple miles then started to sputter again. Replaced coil, did the same. Improved after adjusting timing so replaced the ignition control module this weekend and it drove fine for 2 days before doing it again. CEL the whole time.

Current CEL- 9- cylinder position sensor
48- lean A/F sensor

next thought would be O2 sensor but not sure what the 9 is about. Assuming not vacuum leak, as it is not all the time. FPR or pump? Maybe but car does fine under load. I don't have fuel pressure gauge to check FPR.

Any thoughts? Taking the normal path of $50 parts every couple days is no fun.

 

Fix CEL code 9 first. It's a problem in a distributor sensor circuit. Ohm test the sensor and check the two wires for a short or open.

 

Check that ^^^, then if that doesn't change anything change your spark plug wires and fuel filter. I had that issue before and I swapped my dizzy rotor inside, new spark plugs, wires, and fuel filter and that solved my sputtering

 

The hesitation is most likely caused by the o2 sensor. A very easy way to check is to unplug the primary O2 sensor and drive the car. Does it still hesitate? If that fixes the hesitation issue, look into the NTK wideband for the VX. It's way cheaper than the OEM sensor ($500) but very good quality compared to some of the other cheaper widebands.

On the VX and HX federal models the o2 sensor is a wideband and under the RPM conditions you specifically mentioned it tries to operate in a lean air fuel ratio to get better MPG. If the signal from the O2 is bad the ECU doesn't know what to adjust.

Of course you could still have a problem in the distributor as mentioned above so I would unplug the O2 sensor just to take that out of the equation, and then troubleshoot the other CEL.

 

Unplugging the O2 sensor is an easy and reasonable test, so it should be done. However, once the ECU detects an O2 sensor code, the ECU uses an open loop preprogrammed A/F ratio that is generally on the rich side. I don't think this would cause the hesitation unless the spark plugs are fouled.

 

This x108352

 

Cool, thank you for that. Ill check that during the daylight tomorrow.

Oh ya forgot to mention fuel filter was first thing changed. At least by time this is solved ill brand new mandatory parts. ha.

Sounds good Ill test that too. Seems like a simple test, wasn't sure if it was that easy to check. And ya sounds like the sensor could be adding to the **** up

 

Is there any way that OP will read this and advise on what this ended up being?

I have a 1993 VX w/ the original motor (d15z1) and this is happening to me (once at temp, under light load, and only up to about 2500 rpm... stuttering and hesitating... give it more gas and it sorts itself out) ... I've: replaced o2 sensor, replaced fuel pump, about to replace fuel filter and also have vtec solenoid to pop in... wondering about egr and/or fpr...

Really curious if you solved it for your vehicle... Just 11 years later nbd.

 

I’m not sure if my issue was related to this one, but as I read through this thread it made me think of the issues I struggled with for some time. I was having severe hesitation / fuel cutting issues, with zero CEL / codes, making the diagnosis very difficult, and requiring the parts cannon approach. I finally noticed while watching live data, that my Throttle Position Sensor was reporting “-11%” at idle, and watching it further, it never quite reported correctly. I replaced this with an aftermarket (Dorman), as the OEM Honda part is essentially riveted to the throttle body. After replacing and calibrating the new part, it seemed to correct the issue, but a couple days later, the same problem returned, but wasn’t so severe.
after many other components, time, data logging and banging my head against brick walls…, I decided to obtain another TPS, this time, from I believe Valex Racing. After calibration of the second TPS sensor, my issue seems to be resolved.
Just a thought.. these kind of issues can be extremely frustrating and difficult to nail down.
good luck!

 

It has been my experience that Dorman TPS sensors are notoriously crappy. I have never found an aftermarket branded sensor that was worth a darn for a B/D/H series throttle body, so I have made it a practice to find used OE throttle bodies and cut the OE TPS sensors off of them and transplant them to the throttle body that I am using. The OE TPS sensors are very robust... actual organic failures are very rare. Usually, the failures come from damage... most commonly from smashing the sensors into the fuel filter or firewall/brake lines while removing or re-installing an engine or intake manifold. Damaged wiring also causes failures.