When I said it was starting rough, that meant that when I turned the key, it turned over fine, started after the a second or two (a little slower than usual) but ran really rough for 10 or 20 seconds (like it was ready to conk out), then settled down into running smooth as normally. This occurred maybe half a dozen times over the past month or so. It did not happen every single time I started it, just once in a while.
Have not checked spark on all cyclinders, just one. Spark plugs are fairly new.
How do I check the fuel pressure?
Corvette engine, 5.7L V8
Back again. On the 94 Roadmaster we talked about a while back, it miraculously started up before we did anything to it. It ran for a week or so, and now it won't start again - same symptoms as before. But we'll deal with that later, because...
We have a 96 Buick Roadmaster with only 90,000 miles on it and almost no rust. Love the thing! It's always been reliable, except for today. This morning, it wouldn't let me turn the key. The key goes in but I can't turn it. I tried spare keys, same effect. I tried keys from the 94 Roadmaster, same effect. I tried tilting the steering wheel up and down, same effect. Battery is fine. Vehicle is in Park. What the?
96 Roadmaster started just fine after my husband thawed out the igntion key area; I must have gotten some water or snow in there during a blizzard last night. Oops.
Back to the first car. Did what you suggested - fuel regulator does not leak on the vacuum side. Tried to measure fuel pressure but don't have a fuel pressure gage, so just went by observation: When pressing on that little valve in the pipe on the rail, fuel squirted out a couple inches (assume that's equivalent to 40-some psi) right after turning ignition (and hence fuel pump) on and off. Repeating the experiment but not measuring until a minute or so later, turns out there's just a trickle of fuel coming out of the fuel pipe. Must be a leak somewhere, right?
The car is 18 years old and mighty rusty on the bottom. Taking off the gas tank to get at the fuel pump is going to be a can of worms. Can it be something other than the fuel pump, i.e. something that doesn't require removal of the gas tank?
If we do have to take down the gas tank, do have any suggestions for how to get the gas out of there first?
On second thought, I suppose it really doesn't matter so much if fuel leaks somewhere. Isn't the fuel pump running the whole time the car is running, and the whole time we're trying to start the car, turning over the engine?
The fuel pump sounds OK, at least it sounds just like the one in our newer Roadmaster.
I wonder if 2-3" of squirting fuel is equivelent to 40-some psi. We could check the pressure down by the fuel filter, i.e. before the regulator. What is that pressure supposed to be?
Further update: We borrowed a fuel pressure pressure gauge; fuel pressure is perfect and holds. So it's not that.
It does seem like there's no fuel going into the engine, so now we're thinking the fuel injectors don't inject an fuel, or not enough fuel, and we're thinking it's a control issue. How can we test this?
What do you think?