Hi,

I am seeking some help here because I have 1990 civic DX (1.5L) that has me stumped. It's got 250,000ish miles, with about 70,000 of those since the last timing/belt water pump change. And, it's normally a “great” car, with almost no major issues.

My wife was driving it on the highway, and claimed it lost power and limped to a parts store. (easy parts access, right? But it was raining hard.) I first replaced the spark plugs, as the wires are new. The old plugs did look pretty bad, and I cleaned out a lot of oil, as I need to replace the valve cover gasket. I thought that was a pretty good “smoking gun” so I hopped in and took it for a quick spin, it passed, and I tried to drive it home. And it only ran for about ˝ a mile. So I replaced the distributor cap, no help. I gave up, and towed it home. Rain.

At home I proceeded to troubleshoot, by starting it cold, it will idle/run for about 20-30 minutes. After it's warm, the idle roughens up and it dies when the gas is depressed. (not even drivable to limp anywhere.) So I took out the front O2 sensor, to see if the catalytic converter could be plugged. No help. Then I checked compression. Checks good. Then I replaced the fuel filter, and measured pump output at the throttle body. It pumped 32oz in 40 seconds. Seems ok, so then I checked the “crank angle” sensor in the distributor and it checked bad.(no continuity to ground) but so did the new distributor assy. I'm no the best with a meter, but I thought I could check 4 separate pins to ground. Apparently not. Because I doubt I could be having problems with a reman distributor, so I've got to assume that its good. (maybe)

So, in trying to run it last night, I really felt like everything that it needs to run, (fuel, spark, air, compression.) is there, but some signal is telling the ECU that it shouldn't be running, and that's why it shuts down. My book says that there is no adjustment on the throttle position sensor, and I wonder if that would be why it die as soon as the throttle is moved from idle? I'm also not getting a fault from the ECU. (no LED on the ECU or CEL.)

So, I ordered a TPS, and tomorrow I'm going to drill it off the throttle body, replace the switch, and see where I'm at. Any other ideas that I'm missing?
Thanks for your help.

 

Please clearly describe what the problem is. Does the engine shut off while driving and the engine won't start up again until it's cold?

 

If I was to go out to it when it is cold, (like from sitting overnight,) I could probably drive 1-2 miles, or let it idle in place for 20-25 minutes. After it's warm, even just letting it idle, it will load up and die. After that if I let it set for a hour, I'll idle about 5 minutes, but at that point it dies when the throttle is touched. Some of the time, it cranks, fires/starts for about 8 seconds. (like it has all the required elements to start) and then shuts down. If it has been started at any point in the day, I doubt it would drive for any more than 60 seconds, and it seems to sound kind of rough for that time. Right now I have the exhaust disconnected in front of the cat, to make sure that excessive back pressure is not the problem.

 

Does unplugging the O2 sensor connector make the engine run better? Or have you already tried that?

 

Trying to PM you John but it appears your inbox is full. You PMed me about the Civic you just bought.