I refueled my Volvo P1800 yesterday, and added a bottle of 150ml Liqui Moly Valve Cleaner.
That was yesterday’s morning, and I then drove the car to work. Travel distance from Petrol station to my shop is just around 5km.
At around 6pm, I started my car and drove back home. To my SHOCK and HORROR, the car was behaving badly. The engine is choking and not able to rev. When I pushed the pedal more, it started choking. First gear can barely move the car, 2nd gear can rev slightly only. When going uphill, 2nd gear is struggling. If I push the pedal more, it was even worse. I have to go gently, let the car move slowly to avoid dying.
This was really scary, as before I refueled and added the Liqui Moly, my Volvo was performing well.
Reached home, I removed the spark plugs to check their conditions. To my surprised, there were no oil residual left over. They looks clean, albeit maybe too hot condition. I am not sure if this was the result of my engine cleaned / oil changed, or carburetor adjustment, or because of this Valve Cleaner. Anyhow, the condition does look good or improved from previous too wet or too rich petrol. The spark plugs that I used were NGK BP7HS, one step colder than the recommended BP6HS. I have two new BP7HS with me, so I changed two of the darker condition plugs.
Today, I drove the Volvo again, with a heavy heart + some hope. Condition did not improved much, but I started to get a hang of it. Drove a few rounds around my Taman, and I can shift till Gear 4 without problem. The key point is to NOT press the pedal too much or rev the engine too hard. Gently press the pedal and left it accelerate slowly and smoothly. When pushed pedal too hard at Gear 1 or 2 or even 3, it engine will lose its power and choke. Have to go back to Gear 1 or 2 and accelerate slowly.
I highly suspected that the current loss of power issue is due to the Liqui Moly valve cleaner that I added to my fuel tank. My tank is currently FULL. That’s 43L fuel inside, which will last for 3 weeks. Have to drive the car more often to burn the fuel, though at slow speed. At the mean time, I hope the Liqui Moly valve cleaner is doing its job in cleaning the valve and combustion camber inside my engine, and by the next refuel, my car will perform MUCH better.