won't start without ether, runs well enough after that

[savant]

Hi all. I'll get around to posting in the new members area sooner or later, but for now, I'll just try to summarize the setup.

I just bought a 1991 Eddie Bauer. It's a 4 liter 5 speed with 157k miles. I got an excellent deal on it (I think), but I'm still having issues getting it going.

It doesn't like to start. If I pull the rubber/plastic part of the intake off (let it breathe fresh air), it will occasionally start. If I give it a healthy shot of ether, it always starts. Once I put the intake back on, it runs fairly well. (maybe slightly rough, but I'll deal with that after it starts reliably

So far, I've replaced:
plugs
plug wires
serpentine
oil/filter
fuel filter
air filter
hinge pins on the driver's door (ok, those have no relation to the subject at hand)

I've also put dry gas and injector cleaner in the fuel tank. The previous owner says that it was sitting for about six months before I bought it from him.

I let it idle in the driveway last night for about 10-15 minutes, hoping the injectors might just be fouled. It still didn't want to start on its own after that though.

I've tried searching through the forum a bit (and I've been lurking for two weeks now), but I'm not quite sure what to even search for. Any help would be appreciated. Thank-you.

 

[Opera House]

This gives indication of a fuel mixture that is too lean to start in cold weather. I would suspect the coolant temp sensor (the one for the engine) or the air temperature sensor since the rest of the sensors are pretty much ignored when starting. The other problem could be low fuel pressure. This can be measured on the fuel rail with an old bicycle hose and a gauge. Should be about 39# prior to starting and be able to hold that pressure for a while.

 

[savant]

Alright. Bought a pressure gauge (Dad wanted one for other things), and fuel pressure was fine. It was exactly 40 pounds, steady.

I'm going to look into those sensors. Is there any way to know which is bad, if either. Is one cheap, and a sure thing to try? Where are these things?

 

[Opera House]

At 50 degrees both sensors are about 50K. That goes to about 3K at 190. Don't have a reading below that. Problem would show up if they were shorted or below 50K. Remember there are two coolant sensors. One just runs the gauge.

 

[savant]

Thanks for the help guys. It wasn't any of the things you mentioned, but it got me to the solution.

What happened was that I was trying to find the air temp sensor (never did find it) and I removed the throttle position sensor. I tried starting it with that removed, and it started right up. Now it starts every time.

So thank-you.