Ver Low RPM on Start up with Engine Vibration

[edmond]

I am a owner of a 1992 240sx. Recently, when I started up my car, the RPM was acting so low (400~600RPM) and because of that, the engine vibrated a lot. The vibration went away when I step on the gas pedal to speed it up.

I highly suspect that one of the piston (chamber) was not operating. I pulled out all the spark plugs and cleaned all of them. They all look good but the problem still exists. Now, I am suggested to clean the fuel injector, which may cost me about 100 bucks. I am wondering if any one has has any ideas that I could try before I spend that money.

Thanks !

[locoluna825]

do a compression test first, good results should come out to something like 150-180 per cylinder with a difference of no more than 10 between each cylinder.

[KG300ZXTT]

try adjusting the idle with the adjustment screw use this zerothread/254123

Use fuel injector cleaner first with less than half full gas tank.

[edmond]

Thanks ! I also thought about using the fuel injector cleaner first. There are so many similar products available in the market. Do you have one that you would recommend??

[KG300ZXTT]

I use seafoam and it worked great makes the car smooth. Its like 7-10$