I have a 1991 Honda Accord Wagon LX. I'd like some advice regarding a couple of issues that have troubled me for a while. 1. First, the temp. gauge fluctuates regularly. When I first bought the car the old owner told me the therm. had just been replaced. However, when I recently took the car in for an oil change and had that problem looked at, the mech. informed me that there was no therm. I had the mech. install one but it hasn't quite solved the problem. The gauge does fluctuate less now then before though. 2. The car stutters after about 1/2 to 1 mile after any startup, I give it gas and clutch to help feed it through that roughness then it clears up and doesn't occur until the next time the car is shut off and then started again. Let me point out that when I bought the car about 1 year ago I had new plugs, wires, and fuel filter installed. Other factors to take into consideration: The electrical system appears to have a serious drain (i.e. when the auto windows are operated while the car is idling, the rpm's go down). Also, the catalytic converter is noisy, throaty and there is a hole in the metal jacket around the converter. These are the problems with my car; it does run reasonably well considering. My goal is to try and pinpoint as many of these problems as best as possible and make an educated decision on how much I want to fix. Afterall I bought the car for $775. Oh, it has 238,500 miles. Any help is appreciated.

 

1) Fluctuating Temp Gauge
How much temp change are you seeing? 1-2 widths of needle, 4-5 widths, or more? If temp gauge fluctuations are rapid (< 1-2 secs for a significant change), I would suspect a defective gauge, instrument panel, defective sensor, bad connector, or damaged wiring. If change is gradual over 20-30 secs, then temp change may be real. However, even a slow drift might arise from a faulty temp sensor. If this happens while car is idling, you might want to check coolant temp w/ an IR temp gun to see iftemp change is real.

Check that the cooling system is completely filled w/ coolant and all air bled from bleeder on thermostat housing. Check both cooling fans for operation.

2) Car Stutters When Cold
I would suggest cleaning the throttle bore, throttle plate, and Idle Air Control Valve w/ throttle body cleaner. Use old toothbrush to scrub bore and plate, Remove IACV and clean movement, not electrical solenoid (cleaner can damage). Sticking IACV can cause idle to sag when load is applied. Normally IACV should compensate to hold idle speed as load changes. Clean. or replacePCV and PCV hoses. A new O2 sensor may improve hot engine, low speed idle stability, but won't improve cold engine idle.

You might be able to patch the catalytic converter w/ a steel patch welded over the hole, however you'll have to judge condition of remaining catalytic converter body to decide whether this works. A new converter is expensive unless you use a generic converter. New exhaust pipes and muffler may be necessary also if corrosion is extensive. Honda converters are good so I would stick w/ original if possible.

good luck

 

The in-depth explanation was exactly what I was looking for, thanks for your help.