Alrighty so my z is acting up lately.. It cranks for about 5 seconds then starts, revs to about 1 rpm then dies. Restart it and it starts an idles at 500 rpm, then it takes a solid 5 minutes till it wants to drive right. Rpms at 1 and then the car is driveable, if I try an drive it at 500 rpm no acceleration and just Boggs on me. And when I drive at 1 rpm after sitting, it drives okay until I really step in the gas, it clinks and clonks in the front an doesn't accelerate. I've replaced the o2 sensors, got a new ECM, new fuel filter, I was told by a mechanic it a was lean on bank 1 and 2. He suggested new o2's which I got and it does run better but I'm being told by several ppl its now my fuel pump, cause after the car starts and I drive it for a while (2-3 hours) and turn it off, if I try to restart the car it just cranks. Nothing else just cranks for days.. I need help and don't wanna keep blowing money into my car if its unneeded. Thanks, any input will help out alot! Much appreciated!

 

Have you scanned it for codes? Have you tested the fuel pressure? Has it been checked for a clogged cat?

What trans? That determines the idle speed programming.

What, if any, modifications to the engine?

"1" = 1,000 RPM

 

Yeah an it showed my oxygen low and fuel intake. And so the mechanic recommended new o2 sensors. And no I don't know how to check the fuel pressure or a clogged cat convt.
4L6oE is what I have in it. An nope nothing modded to it.

 

You need the exact numerical trouble codes... that's the only way to tell. Your descriptions aren't meaningful.

You need to attach a fuel pressure test gauge to the Schrader valve, Test it at idle with and without the vacuum compensation line attached to the fuel pressure regulator, Then tape the gauge to the outside of the windshield, and take it out on the road and drive it under the conditions that produce the bog. We can provide the correct pressures if you want to test it that way.

http://shbox.com/1/fp_reg.jpg

If it's running lean, or the O2 sensors are telling you its running lean, could be:

affects both sides:
-faulty O2 sensors (if both fail)
-low fuel pressure
-clogged injector(s) (if clogged on both banks)
-dirty or faulty MAF sensor
-misfires (if misfiring on both banks)
-low system voltage
-water in fuel

may affect only one side:
-faulty O2 sensors
-O2 sensor wire shorted to ground
-exhaust leaks before the O2 sensors
-misfires
-clogged injector(s)

In order for it to be faulty O2 sensors, they both would have to fail. Low fuel pressure or a dirty MAF sensor would affect both banks of the engine.

The engine should idle at 550rpm in gear and 650rpm in neutral, fully warmed up.

A clogged cat will elevate the backpressure on the exhaust system. You attach a pressure gauge to the exhaust, typically in place of the O2 sensor. Again, we can provide the factory numbers if you plan to try it. Any good exhaust shop should be willing to do the test.

 

1) Error code p0029 - Air pump circuit.
2) Lean condition on bank 1 and 2. Oxygen sensors are not responding properly. We recommend replacing the oxygen sensors.

That's what I got back from the mechanic. I've replaced the o2's already. But idk what to do about the air pump circuit. Could that cause my car to feel like it's bogging or misfiring?

 

Did your mechanic give you that info? Codes in the format P0xxx are for OBD-II systems, not your OBD-I 1995. Your code is DTC 29 - Secondary Air Pump Circuit.

Normally that code sets when the fuse for the AIR pump blows. But it can also set if the AIR pump is running when it isn't supposed to be. Normally, the pump runs for a couple minutes at startup to help the cats heat up faster, then turns off. At about the same time it turns off, the PCM switches to closed loop A/F ratio control. If the pump is still running in closed loop (relay shorted to ground) it's possible that is what is causing your lean condition and the bog.

The pump pours fresh air into the exhaust. The O2 sees that, thinks the engine is running extremely lean, and raises the long term fuel corrections to richen the mixture up. But the engine wasn't running lean, so now it's running pig rich. Has your fuel mileage dropped off drastically since you've been having this problem? that would be a certain clue to the problem.

Check the AIR pump to see if it is running more than 5 minutes after startup.

 

Yeah exactly from the paperwork. And if anything when I turn my car on it'll die right away then I gotta restart and mess with the gas pedal to let the car warm up or it'll die again. An there is a fan, I believe it's the one behind the radiator that comes on when the car turns on an this switches on the service engine soon light.