ill phil

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.

Former User

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.

tollickj

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

cbaber

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.

Former User

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.

cvcrcr99

This x108352

ill phil

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