Are fuel pumps multi-speed?

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rlyoung
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Are fuel pumps multi-speed?

Post by rlyoung »

I was in the remote mountains and the van had a hesitation when passing. I didn't try passing after that, and at this point I'm thinking it was bad gas. Things seem to be normal now. However, thinking then that it might be the fuel pump, I tried to lay off of it and not over-work it with a lot of optional acceleration. I understand that a fuel pump sends more than the engine needs, and that the excess is re-routed back to the source. If that's correct, does that mean that a pump runs flat out all the time and the re-routing mechanism deals with the excess fuel? Or does the fuel pump work harder at some times than at others, so that taking it easy would actually be meaningful?

2001 AWD Passenger Van.
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WoodButcher
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Re: Are fuel pumps multi-speed?

Post by WoodButcher »

The flow is constant, if fuel pressure is your problem it could be a dirty filter.
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Topic author
rlyoung
I am smitten with my van
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Re: Are fuel pumps multi-speed?

Post by rlyoung »

I did change the filter and put in some red HEET. The cut-open filter looked very clean. As I said, it's working great now, although I haven't done a fuel pressure test. But it's helpful to know, if I understand your response, that the fuel pump has one constant speed and 'going slow' doesn't save it from working harder.

AstroWill
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Re: Are fuel pumps multi-speed?

Post by AstroWill »

Yes, the fuel pump has 1 speed, flat out all of the time. That doesn't mean that it might not be marginal or there could be something else wrong.

However, if it only happened once, I wouldn't stress about it too much. Standard stuff like checking for spark arcing, checking for distributor drive gear wear, fuel pressure, plugs, etc(full tune up maybe) will give you a good idea of where you stand with your van.

Topic author
rlyoung
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Re: Are fuel pumps multi-speed?

Post by rlyoung »

Thanks a lot.
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