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brokenoutback

Crank no start. Next to no fuel pressure

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First of all, I am just starting to cut my teeth with any mechanical anything beyond the most obvious. Driven by my nature to solve problems but clearly not knowledgeable enough on cars yet. I am YouTube and internet trained. Lol

I have a 2000 Outback with a crank no start condition. Have spark after replacing valve cover gaskets and plugs. No fuel pressure and power at fuel pump led me to replace the fuel pump. Still no pressure when priming or cranking.

Reading codes gives a P0138 which has to do with a likely bad fuel temp sensor. I had only replaced the pump and not the full assembly. So while that might be a thing to do, is that really something that would lead to nearly no fuel pressure? If it were a leak in the fuel lines somewhere, I would expect some pooling of fuel if the pump is working properly. But I don’t see pooling or leaks anywhere visually.

The fuel pressure regulator has a small split in the end of the vacuum hose but I would think that would lead to a higher pressure condition if anything (from my crude understanding on FPR’s).

So I am still back to the fuel pump on some level. Should I replace the entire assembly with the fuel temp sensor and fuel send?

Really trying to avoid hauling it to the mechanic if I can DIY. But I have my limits (as does my better half).

Edit: should also state that I had my concerns with the autozone borrowed fuel pressure kit. Had to T in to the HP line just before the new fuel filter and at first it sputtered a bit of fuel about but next round after tightening and first person witnessing, it did not.)

thanks in advance!

DB

Edited by brokenoutback

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Do you hear the pump running when you turn key to run position?  Listen close to the fuel pump cover.

If not, check for voltage at the connector - blown fuse?

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I certainly hear the pump running. In fact, it sounds the same as it did before I changed the pump. About 2 seconds of hum then off. When I tested with a circuit light, I came on for the same length of time. I am pretty certain that something is happening though as the brand new fuel filter also has some fuel in it. So it’s getting there but at an evolutionary pace.

fuse is fine as well. Have not pulled the relay and tested that but I figured if I can hear the pump, the relay must still be somewhat operational.

Edited by brokenoutback

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So you installed a new pump into the existing pump assembly?

The pump assembly has a metal cap over a pressure chamber - this cap is a known failure point. The ears that hold it to the plastic housing will tear off and the pump pressure blows the o-ring out. 

There is later model that has a filter in that position on the assembly and you can buy the filter which comes with a new (larger, but it doesn't matter) cap with stronger ears. You use that cap and a new o-ring to fix this failure. 

Or you buy a new assembly. 

GD

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If you heard the old pump run and it was a Subaru pump, if you put in an aftermarket pump, I'd put the original Subaru pump back in when you fix the cap.

A little WD-40 on the fuel hoses on the pump plate will make them easier to get them on and off.

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Thanks a ton! Stopped my goose chase. I just replaced the o ring and used the same cap (for now). Pressure with just a key on went up. Then it rose to around 50-60 psi and blew the cap off. I will be looking for a cap in better condition but is there any concern that the pressure rose that much with just a series of key on no cranks?

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Pressure regulator could be bad. Or return line partially blocked. Pressure with key on, engine off, should not exceed 43.5 psi. 

You don't want a used cap - just buy the filter assembly for the newer model with the stronger cap. It's around $65 from Subaru. 

GD

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Did the trick. Ordered the 2004 Forester Internal Fuel Pump Filter and a new o ring. Cleared both fuel lines with a compressor just in case. Solid gold. Thank you again for the advice!

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