Can I step in here and say something? I just now noticed this thread, and it bothers me that something was missed back many, many posts.

It was reported that the fuel pressure showed zero pounds. 180 correctly stated that the engine would not run with no fuel pressure. My viewpoint is that this was a terrible error, the assumption appears to have been made that the zero reading was the problem. As 180 said, it CAN NOT be that you had zero pounds of fuel pressure. IF you actually had good pressure, you wasted time going after the pump/regulator.

You CANNOT troubleshoot something if your tests don't make sense. When a test does not report a sensible answer, you should STOP and redo the test. The car did NOT have zero fuel pressure, 180 has already stated that the car would not be running in that case.

So, where IS the problem? It sounds to me like the pump replacement did not go well and added a new layer of trouble. Sadly, we don't know what the pressure was in the first place because the reading reported was impossible.

The engine (if there is not physical damage like broken pistons or ruined timing gears/chain), needs only two things to run:

1) Plugs that fire at the right time. The plugs are fired by the PTCM/ECM on information largely provided by the Crankshaft and Camshaft position sensors. If both sensors are not BOSCH parts, past experience tells us that all bets are off on how accurate the plugs are firing.

2) Fuel injected at the right ratio of Fuel/Air. For this, we need accurate info from the MAF sensor, good fuel pressure (not too much, but CERTAINLY not too little), and the proper electrical timing from the PTCM/ECM to the fuel injectors. Timing comes from the same sensors as in 1) above.

Seems to me like an ACCURATE measurement of the fuel pressure should be step one. Like 180 says, if you read no pressure but the engine *kinda* runs, you cannot have zero pressure and if that is what you see, your pressure test is not being done right. Without good information, you are not troubleshooting, you are just going in circles.

With the developments in the last few posts, I'd say its time to really look at the pressure. Get it RIGHT first, (54 to 61 PSI) then, if the car won't run right, move on from there. My next step would be BOSCH cam and crank sensors, even if there is no P-code being tripped or no engine light.



I hate to say it, but:
Of course, this all assumes you didn't start out with a tank of bad gas.