Hard cold start unexpected fix

[PEZ2]

Have been struggling with a 13 year wake up of a 90 325i. Rounded up the usual suspects ICV, O2, CPS etc with no luck. Plugs are still looking rich and cold start up is poor and needs “ foot” help for the first 15 to 20 seconds unlike my 2.9l 86e. The fix revealed itself as a fuel leak. On the 90i there is a short rubber line that connects the hard return line ( body) to the tank. The small bend it had to avoid the fuel filter collapsed to a crimp, which started to leak. It appears the crimp was enough to cause the return line to become pressurized ( the leak shot 2 feet) resulting in the FPR to be unable to dump fuel to the return line to control rail pressure. Once the 4 inch section was replaced startups are good, plugs look normal.

[LindrelT]

Good job! At least it was cheap parts wise, just some time!

[TobyB]

Oh yes, not a huge surprise- this is why a fuel pressure test is so useful...
I found a return line blocked with sludge that way once...

t

[Lippy]

Why was it crimped? Did someone use too long a hose?

[Panici]

Glad you got it! Wouldn't have expected a damaged return line.

[digger]

there was another thread with blocked return line and if you just looked at fuel pressure you may conclude the FPR was faulty so proper diagnosis is key