Quote:
Originally Posted by Al Skierkiewicz
if you depress the accelerator after it starts, will it continue to run?
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Here's the test sequence and results:
Code:
1) Turn key from OFF to ON and pause:
can hear fuel pump run for about 2 seconds and then stop
2) Rotate key from ON to START:
Engine starts immediately and idles smoothly, quietly, at correct speed
3) Before misfiring begins, press accelerator:
Engine bogs down and stalls.
My working hypothesis is that the fuel pump itself is fine, but it's not being controlled properly once the engine is started. A fuel pressure test would only confirm what I am already pretty certain is true. It wouldn't help me find the cause. If I had an appropriate fuel pressure gauge and all the proper fittings I'd probably test it just to be sure... but in the meanwhile I'm exploring if there are other simpler things I can check -- things which might be interfering with the proper operation of the fuel pump once the engine has started.
I visited three auto parts stores and two auto shops this morning. There appears to be much confusion concerning fuel pump operation and fuel pressure regulation on this engine for this model year.
On the one hand:
Chilton's says there is no pressure regulator: The PCM (Powertrain Control Module aka engine computer) controls the speed of the fuel pump to regulate to the desired fuel pressure. To do that, I would assume the PCM would need a fuel rail pressure sensor, and sure enough Autozone's website shows a drawing of the top of the engine with a Fuel Rail Pressure Sensor (FRPS).
On the other hand:
None of the auto parts stores (including the afore-mentioned Autozone!) could find a FRPS listed for this engine. They all said the engine uses a FPR (Fuel Pressure Regulator). The auto shops I visited thought the engine has a pressure regulator. One even gave me a quote to replace it.
There is a large hard plastic cowling covering the top of the engine, hiding from view the area I would otherwise simply look at to resolve this question, and it is securely fastened with a weird fastener whose removal process I have yet to figure out.
Later today I will take a photo and post it here, maybe someone has seen something like it.