hard starting

[tahiti350]

I've got a'90 Legacy LS wagon, N/A, Automatic. When it's totally cold it will fire adn die, then just crank over unless I start feeding throttle into it. Kind of like an overly tight choke on a carburated engine. Once it has fired adn run for a few seconds I can let it come beack down to idle adn it's a little bit rough, but will idle and drive okay.

When I got it the O2 sensor was not hooked up, spliced the leads in adn the check engine llight went out and has not been back on, everything else seems normal.

Idea's?

Gary B> Tahiti350

[vrg3]

Can you run my scantool? It might help you figure out whether or not the coolant temperature sensor is reading correctly.

[tahiti350]

I've got a high dollar scan tool, but thought the temp sensor would flag the check engine light. I can tell a difference in teh way it runs once the temp gets up to normal. Just hard to start cold. I'll try to get the scanner on it and check it out again.

[vrg3]

It won't throw a trouble code if it's just reading a bit off.

[555BCTurbo]

+1 I had coolant temp sensor problems and it never triggered a CEL

[tahiti350]

Have this week off, will try to get the scanner on it. What should the temp readings be?

Should I disconnect the battery and clear the computer first?

It's wierd, as the O2 sensor was dis-connected when I got it, and it started fine. After I re-connected it the check engine light went out, but it became hard to start when cold. Have to "give it gas" like a carb equipped engine to start, then once it stabalizes (5-10 seconds) I can let it idle and go open the gate. I should be able to just turn the key without touching the throttle, right??

[Richard]

+1 I had coolant temp sensor problems and it never triggered a CEL

Actually, I rocked it for a few months until it finally got bad enough and shat out a code.

[vrg3]

Well, when the car has been sitting for a long time, the reading should read about the same as the ambient temperature.

When the engine is at full operating temperature, it should read around 170 to 200 degrees.

Wait -- unplugging the oxygen sensor makes this problem go away? If that's the case, you should suspect the oxygen sensor. Look at its readings with the scantool.

Yes, you shouldn't need to touch the throttle to start the car, except under maybe the harshest circumstances (like if you parked in a spot in Fairbanks, Alaska for an hour in January and forgot to plug in the block heater).

[tahiti350]

I'll check the O2 sensor also, but when hooked it up I put the scanner on it and everything looked good. But, problem did start immediately after I hooked it up???