Car won't holder fuel pressure, slowly dies

[trunks]

Fuel pump runs the entire time. If I shut the car off and restart it I'm good for about 10 miles and then it slowly leans out and i hit fuel cut eventually. Brand new alternator last year and all electronics are fine. Is it the fuel sender?

Any help greatly appreciated.

Thanks.

 

[smokeyjpn221]

Fuel pump runs the entire time. If I shut the car off and restart it I'm good for about 10 miles and then it slowly leans out and i hit fuel cut eventually. Brand new alternator last year and all electronics are fine. Is it the fuel sender?

Any help greatly appreciated.

Thanks.

i'd say check the fuel pressure regulator and then the pump...gool luck

 

[trunks]

I'm soaking my injectors now. There weren't any kinks in the fuel lines. Hopefully she'll run good tonight when I put it back together.

So yeah, I probably didn't need to buy new parts, but luckily I've a got a Talon waiting to get worked on so I can reuse the old AFPR and pump in that.

 

[crimsondragon]

Glad to hear you found the culprit. As for cleaning them, soak them in gasoline.

 

[MuffinMan7580]

The gunk is not from the e-85, but the grime that was in your line after the fuel filter. Replace your fuel filter. I hope your AFPR was anodized internally.

 

[trunks]

So I went for a drive and I runs good, but I've still got two issues. The FP gauge won't go below 50 now. Is it just that the gauge is hosed? Second, my o2 reads 0 at cruise. I'll occasionally go to .02 but mostly 0 at idle and light cruise. Is it just that my base timing is off? It does cyle up to .85 at moderate throttle (still working on the tune). It is also a new sensor.

 

[Calan]

Make sure the spring in the AFPR is the correct one. Some Aeromotive AFPRs have been known to ship with the wrong spring (mine came with two and I had to swap them).

O2 sensor issue is probably due to the E85, but I'm from an E85 expert.

 

[trunks]

I just swapped in a fuelab afpr. When I turned the pump on with link, I had bearly turned it down and it was right on 37 (6 bolt). Start the car up and she jumped to 52. I should barely run if the reading is accurate, I would assumeWTF.

 

[Calan]

Have you checked to make sure you don't have a clogged or kinked return line between the AFPR and tank? It's sounding more and more like it.

 

[trunks]

I know what you mean. But it looks fine by the tank. I guess I'm just going to have to jack it up on 4 stands and crawl under there to make sure all the way.

 

[Calan]

disconnect it at the AFPR and tank, run the tank end into a big bucket and blow some low pressure air through it from the AFPR end. (be careful that you don't spray gas everywhere). Once the line is drained and dry, crank up the pressure and see what kind of airflow you get out of it at the tank.

Seems like that would work anyway

 

[rush2252]

+1 e85 is pretty rough on older fuel lines etc. Im betting the return line is plugged like calan stated.

If you cant blow through it theres problems. Try compressed air turned down to 8-10psi see if the tank bubbles.

Kolby

 

[trunks]

I've reinstalled the pump about 6 times now trying to get the gas gauge to work. The shop that originally installed it put a 1 foot section of rubber house from the pump to the 6an ss line. There's just enough hose that I can barely get the pump out without disconnecting it, but I've been pulling and bending it pretty good. I bet that section is the problem.

I'll check the return line too then. Maybe I should just install a new return line otherwise.

 

[trunks]

Sorry double post, but I'm thinking you guys are right. I had ran the pump with the return line disconnected from the pump and it really shot out of there. Way more than the pump to sender hose did.

 

[Calan]

You know...this may sound silly, but are you sure you didn't accidently swap the input with the output on the AFPR?

The reason I ask is that you said with the pump on it it is fine, but as soon as vacuum is applied (car started), the pressure jumps up. This is exactly the opposite of what should happen. I wouldn't think that your AFPR would work in a "reversed" manner (I know nothing about how the FuelLabs are set up), but it's odd that your seeing what you are.

My first thought was that as you increase the required flow, a blockage in the return line is causing input pressure to rise. But now that I think about it, you shouldn't be getting that much more flow between the pump being turned on and just idling the car...in fact, pressure should drop when the car starts due to vacuum being applied to the AFPR.

Do you have a vacuum source you can put to the AFPR with the car off and the pump running? Would be interesting to see what happens.

 

[trunks]

I hooked it up just like the old one was on there - input on the right, return out the bottom, left side blocked off - so I'm pretty sure thats correct.

Is that return hose to the pump 1/4"? I think I'm just going to ss 6an the return line since it should probably be done anyway.

 

[Calan]

Is that return hose to the pump 1/4"?

The upper hard line is...roughly.

A -6AN SS line will clamp to it just fine if you use a good fuel injection-style clamp.

I think I'm just going to ss 6an the return line since it should probably be done anyway.

That's an awfully expensive return line

EDIT:

It's closer to 5/16", at least on a 1G. Here's a couple pics of mine:

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[trunks]

$80 worth from JEGS. There's a reason my car is green - $$$$

 

[trunks]

It's finally over. My o ring on the fuel return line inside the pump was sitting crocked since the unit wasn't on there quit as far as it should have been. That was blocking the return fuel. Luckily I hadn't installed a new return line yet.

Another newb lesson learned.

 

[Calan]

I would never have guessed that to be what was blocking the return, but good that you found it!

 

[trunks]

Yep, it's always something stupid it seems. Thanks for the help, you led me in the right direction.