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Subject Changing out fuel level sender -- ? about fuel pump...
Posted by thumper300zx on September 17, 2007 at 12:34 PM
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Message Hey -- I'm finally pulling out my fuel level sender to get it replaced. When I first did upgrades to STAGE III, my fuel pressure at idle was right around 35. At ZERO vacuum it would be around 41. At full boost it was around 60-62. Most people said that sounded a little low. I replaced the fuel filter, and I've replaced the damper and FPR. The fuel pressure remained the same. I have also replaced two injectors over this time -- one that went completely dead, and another that just showed a bit low on the resistance.

The fuel pressure seems to be getting lower. Now I idle around 32 psi, at zero vacuum it's about 40, and at full boost about 58-60.

Based on this information, should I be considering fuel pump replacement since I'm gonna be right there? Or do you think this could point to anything else like the contoller?

At idle with vacuum hose removed from FPR, I get 40 psi fuel pressure (same as at 0 vacuum while driving).
Fuel pump makes the very slightest buzzing noise -- I've heard it make a bit more noise in cold weather. Not really loud, but it does buzz a wee bit.

Fuel pressure maintains after shutdown. Reads .6 ohm from pin 3-4. (spec says ~.5 ohm)

Here is the whole old assembly -- what all should be replaced? Does the fuel pump come with just the pump, or does it come with some of this other stuff? (I have the "BAREBONED" sensor assembly already). The hoses are all incredibly soft like they are brand new. But there's the check valve at the top, something that looks like a carbon filter, and the screen at the bottom (not pictured). Any reason to replaced these things? They look o.k.


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