[Mattman]

So. 190+k on the old pump and intank filter meant driving my 2009 jimny was getting pretty rubbish at times (especially going around tight corners at speed), but the final week of old pump meant "priming" the fuel system by turning ignition on and off a couple times before cranking over, because no pressure right?

buy new pump and intank filter house shinding ($180 total for both, not bad)

Spend a couple hours dropping tank and replacing the bits. Took some flakes out of the bottom of tank while i was there, the old pump was traaaash. Filter sock had rubber against the floor of the tank and worn out. Plenty of bulldust buildup in the pump (didnt think about this as a continue) reinstall tank, turn key and woohoo. Go for a drive around the block, then see flashing light of doom. Limp back to driveway running hell rough. Turn off car, open bonnet, take fuel rail off and see brown dust filled fuel leak out. Left pump going whilst disconnected until fuel was flowing the same colour it goes into the tank.

Still runs like shit, get some spare injectors and reset ECU. Runs much better, a little rough at idle due to mixing injectors, actually pulls now above 4k. Win right?

Well no... It has started to need a couple 'priming' key turns before starting up otherwise it will cut out after 3-5sec and then need to go through the old prime 3x and then start with some accelerator.

What can i do to try alleviate this annoying issue? Is this a fuel leak somewhere causing a drop in pressure (nothing underneath or fuel smell anywhere)

[MrRocky]

Fuel pressure regulator diaphram might have a hole in it
Have your injectors cleaned as well, until they are 100% cant properely diagnose anything

[Gwagensteve]

There a few things here that don’t make sense. The fuel system is sealed when the car is in use I don’t understand how you’re getting a lot of bulldust inside the tank and past the filter.

Rough running won’t be caused by “mismatched” injectors unless my mismatched you mean different advertised flow rates. A set of injectors will only have a couple of % variation across any random 4. I bet they’re not flow matched in sets from the factory.

If the filter has failed on the old pump it would be wise to work out why so it doesn’t happen again. this isn’t common. Has the tank been dented, pushing it into the pump?

I’m with Mr Rocky- I think the real problem is the pressure regulator has failed.

[fordem]

Gwagensteve wrote:

The fuel system is sealed when the car is in use I don’t understand how you’re getting a lot of bulldust inside the tank and past the filter.

Maybe he needs to look at where he's getting his fuel.

Here we have a government owned chain of petrol stations that supplies "cheap" fuel, and they have quite a reputation for contaminated fuel.