86civicsi

My 86 civic Si has been sputtering, stalling, hesitating, or whatever you want to call it and then sometimes dying at highway speed and at normal operating temperature. Seems like it does it after driving about 3 to 4 miles at highway speed. Sometimes when it is at normal operating temperature I will have to wait a few minutes before it will restart. Also, after reaching normal temperature, it will die at stops, and it will sputter and/or die at lower speeds as well. All I've done so far is replace the fuel filter. That wasn't it. I've toyed with the TW sensor because of the ECU code 6 (2 middle lights on steadily, but there may be other codes stored in there; I've never knowingly reset it.). The TW sensor is getting 5 volts and has about 1500 ohms when cold (outside air temperature). The new one which I may return is getting the same ohms at outside temperature. Should I check the old one again at normal operating coolant temperature? I think then maybe it should be between 200-400 Ohms, at least that's what Honda dealer told me, but said at ambient temperature, which can't be right. Gosh darn, after viewing a lot of similar posts, seems like it could be any one of a dozen or so things. Any help?

Possibly unrelated, it has had the infamous surging idle for about 2 years now---bounces from about 1000-2000 rpm. I've just lived with that. Think that may be the ACV or some other control valve or sensor.

Boy, the body is sure starting to look like hell, but I love this little thing. Got about 288,000 on it. Sure am wanting to get 300,000 on it. Engine still seems ok apart from the above. Tranny's getting a fair amount of play in it.

Any help or input would be most appreciated. Thanks.

86civicsi

ED9man

ground?

86civicsi

ED9man: Thanks for reply.

You're talking the ground from valve cover to body? I did notice it was a little loose yesterday at the valve cover. I'll tighten it and see what happens. This is a very erratic intermittent problem. Yesterday was at lower rpm and died; would not start for 5 min. or so, but when it did was fine.

Also, checked the code after it died this last time. Was Code 1--ECU failure. If that is true then it is again a very erratic failure. If it is the ECU, why would it fail so erratically? Curious. Thanks.

Kai

I'll have to dig out a picture for you, there is a little air control type valve beside the throttle body with a plate on top, held on by two screws. Take out the two screws and you'll see a little peice with two notches, for a screwdriver like tool. That little thing tends to get loose after a while and cause a surging idle. Tighten it down as much as possible, and put the cover back on with a new o-ring.

That cured the problem in my old '87 Si.

86civicsi

Kai, thanks. I think I read your earlier posting of that curing the surging idle. I had planned to do that. Sorry you had to reiterate it.

FYI, I checked out the TW sensor based on the stated problem for Code 6. I think it is bad. Stuck a 330 ohm resistor in the TW sensor plug which would approximate a TW sensor at normal operating coolant temperature. She ran ok with no sputtering, coughing, or hacking. If it keeps running ok with the resistor, I'll replace it. Just watching it for now.

Thanks again.

ED9man: Thanks for the suggestion. Tightened the ground cable at both ends. Took it for a spin. Thought that had cinched it, but started coughing and sputtering again after several miles. But, it was a little loose, and needed tightening.