I bought a 94 civic cx last week with 150,000 on it. timing belt is new, fuel filter is new, engine flushed, new oil, was inspected with no problem, that "restore" stuff.

The car sat in a garage for a year before I bought it. I have no idea if the plugs have ever been changed. Plug wires look to be original. It had almost a half tank when parked that entire time. I filled it up with midgrade and it drove fine.

Tonight was the first time it has seen over 70 in a year. I stayed at that speed for about 20 mins. When exiting the highway, the car had a horrible rough idle at the toll booth. Thought it to be nothing but it persisted. Left it sit for an hour while I ate and still rough idle. Drove home but only 65 this time.

It still idles hard. Sounds like its bogged down but will not stall. Could it be as simple as plugs? Or am I looking at something bigger? Remember, this only started after driving a little spirited. Well, as spirited as you can be with 70hp

 

Describe the idle a little better for us. Is it bouncing or is the car just chugging like it's about to stall? Are there any codes? Can you pull the plugs and take a picture for us? What color is the spark from the distributor coil?

 

its chugging. all through the rpms. ill pull the plugs tomorrow and take pictures. im not sure how to check for codes but no check lights are on.

 

whats it idling at?

 

prolly dirty iacv, seafoam ftw

 

i dont know what its idling at. doesnt have a tach. i added stuff to get rid of any water in the system this morning. it did stall today at a stop sign.

as a side note, the problem is worse when any electronics are on. I.E. headlights, heater...

 

your idle is prob just set to low, turn it up and see if it goes away

 

Sounds like a map sensor problem, and CEL's. Pull the plug on the map sensor and see if it changes.

 

that sounds feasible but it vibrates hard ALL through the rpm range, not just when idling.

Im taking it into my uncles shop tomorrow morning and he will figure it out. ill let everyone know what it is cause this type of thread seems to be common, but all the others have modified engines. mine is stock and doing this.

 

after compression test this is what was found out. piston ring in cylinder 3 is cracked. compression was 150 150 30 150. im contemplating a newer engine or if someone wants a 94 civic hatch ill hand it over for 1200 to the first person who wants it.

 

yeah the next thing i was going to say was an ignition/combustion problem, i guess that explains it.

 

so how much would it cost for new rings and whatever else i might need? its going to be done in house hopefully. the cylinder wall is not scored so i shouldnt need to bore over.

help?

also still on the table that if anyone wants it. $1200. if you have an engine laying around or want a hatch this is a great deal. body is in excellent condition. all mechanicals working (except piston ring). non-molested car. great project car platform.