fuel pressure regulator

[duckloads]

I replaced the return hose on my fuel pressure regulator ('91 535i) this weekend, and I noticed something real funny. When I removed the hose there was no fuel in it. None. Nothing.

Is this an idication that my regulator has locked up not allowing any return? Please advise.

Thanks

[Javier]

Javier

[duckloads]

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[grave77]

Well I've been suffering from this thing before 3 months ... this regulator is very sensitive, if u have no gas at all that means 2 things; either ur regulator valve is stuck and u should have a very bad idle with black smoke, or ur fuel pump is warn out and lost its pressure. I think for the 535i it should have 3.0 bars valve. so u can check the pressure with a meter and then most probably the valve is done. also check the air hose if its cracked then it will retain the valve closed. but still the fuel pump should be powerful enough to squeeze the fuel out of the valve. hope that would help

[duckloads]

Thanks for the response. The idle in my 535i is real rough but with no black smoke. I have not been able to find any vacuum leaks or any other cause for the rough idle. The fuel return hose I replaced had a kink in it. I'm not sure fuel could could have gone through it. I replaced the question-mark-shaped hose with regular fuel injection hose until I can order the proper molded hose.

Where is the best place to hook up a pressure gauge on this fuel system?

Thanks

[Bill R.]

return. You'll have to use a T fitting to put the fuel pressure gauge inline




Thanks for the response. The idle in my 535i is real rough but with no black smoke. I have not been able to find any vacuum leaks or any other cause for the rough idle. The fuel return hose I replaced had a kink in it. I'm not sure fuel could could have gone through it. I replaced the question-mark-shaped hose with regular fuel injection hose until I can order the proper molded hose.

Where is the best place to hook up a pressure gauge on this fuel system?

Thanks

[grave77]

Well without too much investigation u can try one thing, if u can full throttle the engine then just replace the regulator valve and smile!! but don’t use any other air hoses than the BMW ones or same diameter at least. one stupid tech replaced it with the merc. plastic ones and it was causing the engine to idle roughly!! as the e30 engine is so sensitive to air leaks !! good luck I hope this will solve ur prob.

[InfernoM3]

I replaced the return hose on my fuel pressure regulator ('91 535i) this weekend, and I noticed something real funny. When I removed the hose there was no fuel in it. None. Nothing.

Is this an idication that my regulator has locked up not allowing any return? Please advise.

Thanks
How do you replace the vacuum hose on the other end of the fuel pressure regulator. Mine is all dry and cracking?

[Kalevera]

Two things:

- The vacuum hose on the cylinder bank side of the FPR is an easy thing to replace. I did it a few weeks ago. Got a length of the PVC hose from Patrick (check the ETK) and replaced it. The only questionably difficult part is reaching the nipple on the intake where it connects. Mine was cracked to all hell and I had to use a pair of needlenose pliers to remove the bits and pieces. A 5 minute job.

If the FPR issue is still in play: I don't think you're supposed to have a lot of fuel in the question mark shaped tube. Mine was "wet" but not filled with stuff.

best, whit

[InfernoM3]

Two things:

- The vacuum hose on the cylinder bank side of the FPR is an easy thing to replace. I did it a few weeks ago. Got a length of the PVC hose from Patrick (check the ETK) and replaced it. The only questionably difficult part is reaching the nipple on the intake where it connects. Mine was cracked to all hell and I had to use a pair of needlenose pliers to remove the bits and pieces. A 5 minute job.

If the FPR issue is still in play: I don't think you're supposed to have a lot of fuel in the question mark shaped tube. Mine was "wet" but not filled with stuff.

best, whit
Do i need to replace the nipple piece also? I don't want to pull out the hose and find out that I need this part also? going to BMA on sat to pickup the items.

[Kalevera]

No, I don't think so...Mine was fine, and it's 15+ years old. Granted, I wasn't able to see it as I had to grope around in there to get the new hose fitted.

best, whit