2018 Fuel Pump Pressure

4 stroke engine,carburation, EFI, and exhaust discussion

2018 Fuel Pump Pressure

Postby Twomotokiwis » Wed Jun 30, 2021 11:23 pm

Good evening gents

Trying to trouble shoot a soggy throttle response and poor starting, trying to find out fuel pump pressure what it should be.

This seems to be a well kept secret or I am looking in the wrong place, I have googled it a LOT but no bueno, can anyone help with this?

I have had mine tested and it sits at 42-43 PSI.

Also other suggestions as to culprits to kick out the gremlins welcome....

Cheers Andi
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Re: 2018 Fuel Pump Pressure

Postby NNW » Sun Jul 04, 2021 8:51 am

That's the right pressure i believe. That's what my replacement regulator is at and throttle response is great
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Re: 2018 Fuel Pump Pressure

Postby Darkside » Sun Jul 04, 2021 11:51 am

What model bike? How many miles? Have you tried the passive reset? I have an 18 390 rrs and had the dealer install the fmf map. I do a passive reset every time I ride. I recently cleaned the stepper motor actuator. If you shine a light down the airboot and see dirt on the buttertfly valve, you probably have dirt on the sensors too.
Randy
2018 390 rrs, 2014 300 rr re, 2010 ktm 450 exc
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Re: 2018 Fuel Pump Pressure

Postby Twomotokiwis » Mon Jul 05, 2021 9:44 pm

Heya Darkside...grab a beer :D

It is 2018 430, always been a really poor starter, we have since checked a 480 and his was 42-43 psi as well so happy with that.

Went for a ride two days ago, went ok till 100km away from help then for no reason it would not start, wind over but no hoof. I didn't have my tools with me as I was pretty much on a gravel road ride, big mistake.

An hour and 25 minutes later it started, no reason why. I few days prior we put it on a dyno trying to trouble shoot its issues and it was running around about 10.2 : 1 fuel ratio at early and cruise rpms so it was way too rich, the dealership installed a 2020 map not even knowing if it would work but it did, dynoed 39 hp which is a little shallow as well.

When the bike stopped on my gravel road ride I checked what I could, pulled the black cover off the left hand throttle body, the throttle spindle was seating properly and firmly.

On the return home coming into a corner the revs just hung at 4-5k, I shat myself.... grabbed the clutch and brakes nearly tucking the front..., turned the bike off, it started this time (thankfully) and the idle was normal

When I made it home I did a factory reset till fan come on etc but have not ridden it since....

I am now wondering if I can fit a smartcarb to this bike to ditch the shithouse fuel injection as it has been no end of trouble.

Items replaced by dealership are stepper motor, air temp sensor and TPS, no grub down the intake tract she is clean, the throttle body has some end float so the dealership want to change that out saying they are the same as Sherco which had a bad batch with too much end float.

That's it, fire away with any questions and suggestions to try, the serious hanging idle and NO start is a new one, has only done that the once.

Thanks guys

Andi
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Re: 2018 Fuel Pump Pressure

Postby Darkside » Tue Jul 06, 2021 9:56 am

hmmm. I wouldn't have thought the 20' map would work. I thought the 18's had single injector and the 20's had dual injectors
Randy
2018 390 rrs, 2014 300 rr re, 2010 ktm 450 exc
Darkside
 
Posts: 449
Joined: Tue Jul 30, 2013 12:53 pm
Location: SF Bay Area

Re: 2018 Fuel Pump Pressure

Postby Twomotokiwis » Mon Aug 30, 2021 1:16 am

Heya fellas, a quick update, as at 90 hours the bike never had engine braking from new and it was a wanker to start when warm, a bit of anger and some strong words finally got the throttle body replaced, the same issue as the same year Shercos, excessive play in the spindle.

You could hear it clack side to side and closed throttle and visibly see the butterfly shaft move, at WOT you could airbnb the space to four families there was that much room :lol:

Long story short, has great engine braking, starts like it should and does what a 430 should do.

Thanks for the help along the way.

Cheers Andi
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