Snapes

Hi all,
New to the forum as I just bought and broke my RST cabriolet. So as its a cabriolet you can assume it's an XR3i with MFI Turbo conversion. The fuel pump started priming with a low pitch grinding noise, like brakes grinding. It' then Didn't start the next day but did the day after but wouldn't idle and then it stopped again and then no life at all. I have power to both relays, to the metering head etc.... So I've gone under the car looking for the pump and its not on the spare wheel tub.... Here we go I thought. I took an executive decision to drop the tank and I have an "in tank" pump with enertia/ fuel cut off in the spare wheel well. So my question to the experts is what car does this tank originate from? I have been under the impression all Mk4 XR3i and RST had external pumps.

GINGExR2 T

iTrader: (1)

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What year is the car, 90 spec EFi cabbies had an in tank pump the same as the XR2i and Fiesta RS Turbo. Mine packed in within 500 miles of fitting a turbo lump, just get an updated one, be carful on EBay as there are copies, got mine form Motorsport Developments,

Ginger.

Snapes

Thanks Ginger, I have since been able to drop the tank and indeed found that is EFI at the tank. It has a Walbro GSS340 high pressure pump and it runs up fine on a bench test. Put it back together and magically it's working however now I am back to the inability to idle. Metering head? Runs fine, starts fine, didn't miss or splutter just stalls on idle. There are no air leaks, or fuel leaks, it does smell like it's running rich tho. I have backed the mixing screw as far to lean as I can still no difference idle screw wound up etc. any thoughts?

studabear

Will a efi pump flow for mfi? iirc a tuner told me mfi runs a lot higher pressure than efi?

Snapes

I'm guessing that's the reason for the internal upgraded pump. I googled the one that's fitted and it's sold as a kit to completely replace (including wiring) the original but retro fits to the existing sender. My MFI knowledge is not up to the job really I'm more an EFI kinda guy. If anyone can recommend a decent tuner in the South east for RST?

studabear

Frenzy performance tuning might be near you in Suffolk. Karl the owner is a trader on here.

Snapes

So I was going over everything again as something's not right where as it primes one minute and not the next. So while testing for power and earth continuity I also checked for resistance at the pump and there it was 75 ohms. Seems as tho the upgraded pump has been drawing too much and the looms got a bit melty.....