Sorry for the delay on an update. Once again work got in the way of life.

Recently I decided to just go though the service manual and start checking systems. I discovered that the Fuel Vapor Canister purge valve was not working. I would not hold any vacuum. I would squeeze the vacuum pump handle and the gauge would go up then immediately drop when I stopped. That's when I thought back and realized that I had been smelling a little gasoline lately. I started thinking about the possibility that the purge valve was fluttering trying to hold the pressure.

I spent the next few days trying to find a replacement. It's on the way.

However, after I ordered the replacement I decided to check to see what happens when I drive the car with the canister operation bypassed. I plugged both the upper and lower vacuum lines and took a drive. No difference, the noise remains.

Then, yesterday I had to drive the car to work and I noticed it seems to by running a little hotter than usual and it is really low on power over 3000 rpm. I have to admit, it does seem like a clogged exhaust. I think I need to measure the back pressure.

Well, the new fuel vapor canister came in, has been installed, and has been road tested.

As I expected, no change but one more possibility removed.

On the test drive I noticed some unsteadiness in the engine during deceleration. While slowing down, below 2000 rpm or with the throttle slightly open, (when the fuel to the injectors is on) it felt and sounded unusually uneven. Not the normal rumble and deceleration.

This leads me to suspect injectors again. I think this weekend I need to listen to each injector with the stethoscope.

Here's the latest update:

I fabricated an exhaust back-pressure test kit using an old O2 sensor, some hose and a pressure gauge (0-5 psi range).
Results:
At idle there was 0 psi. It reached .5 psi at about 2000 rpm and got to 1 psi at a little above 3000 rpm. I took it to red-line and almost hit 3 psi.

I used some Risoline to quiet the noisy lifter then, after a few days, used the mechanics stethoscope to listen to the lifters and the injectors. The lifters all sounded pretty quiet. The injectors seemed okay, from what I can tell. I don't really know what they should sound like. Lifter and valve sounds I know. Injectors . . . not so much. They were all clicking and all sounded about the same.

The other day I had to drive the car to work. Since it had been doing okay at low and steady speeds and on level ground I thought I would be okay if I stayed off the freeway. Well, on the way home it started getting really bad. It did not want to go up hill. I made it to within about half-a-mile of home and it would go no further. No power at all. It came home on a flatbed.

Today I decided to do a compression test. Here are the results:
1 - 155 psi
2 - 155 psi
3 - 160 psi
4 - 160 psi
5 - 170 psi
6 - 155 psi

I was really sweating the compression test because the number 2 exhaust was cracked and leaking when I bought the car. I feel a lot better now!

When I pulled the plugs for the test I noted that 1-4 were pretty sooty and 5-6 were pretty normal. I cleaned the plugs and checked the gaps and they look pretty good. It would make a lot of sense that if the mixture was not the correct 14.7-1 you would get a lot of soot.

Tomorrow I'm planning on removing the upper intake and take a look. Monday I plan to order new injectors (I've been saving during all this) and anything else I might need (EGR tube).

quote Originally posted by Jim_Martin29: I open the throttle and the engine hesitates, like it’s taking a breath, then it tries to accelerate back. When I do close the throttle the car surges forward slightly.

Both symptoms are classic weak fuel pump or restricted fuel supply system.

You can have good pressure at idle & revving the engine but if you leave the gauge connected and drive the car the pressure will drop when the
symptoms occur, not enough fuel volume to keep the pressure up. You back off the gas, higher volume of fuel not needed now, pressure goes up &
the car surges forward for a second.
Could be a bad pump (can't supply enough volume under a load to keep the pressure up), plugged fuel filter or other restriction in the fuel line.

Whenever I test drive a car with a low power problem but no misfires the first thing I do is accelerate & back off the gas a little - if I get a power
surge it's 99% a fuel problem, usually the pump.
If not, 2nd check is exhaust backpressure. Your 3psi is slightly high but shouldn't cause your problems.