GSX1400 Owners .org

Technically Speaking => Fuelling => Topic started by: Simonic on Thursday, 11 March 2021, 10:22 PM

Title: Starting/Priming
Post by: Simonic on Thursday, 11 March 2021, 10:22 PM
Hello Gents.
Bit of an odd one here.
I'm having some starting trouble.
When i turn the ignition on the system starts to prime and then stops halfway thru the cycle and gives me the F1 light. This mostly happens from cold but sometimes from hot.
If i turn off and go back on again most times it will do a full prime second time but sometimes it takes afew more go's.
The battery is new and fully charged.
The tea bag is new.
I replaced the pump with one of the hi-flo pumps 3 years ago.
The bike has the hi pressure filter bypass mod with a new inline filter.
The injectors have been cleaned by injector clean and have new filters.
I'm wondering what else to try.
I'm thinking of selling the bike soon and can't sell it like this.
One other thing maybe i should mention but i can't see how it would be connected is that the fast idle does not work,however it's been like that since i bought the bike 4 years ago and this starting problem has just begun in the last 3 months.
Thank You Gentlemen
Title: Re: Starting/Priming
Post by: Hooli on Thursday, 11 March 2021, 10:58 PM
Strip & clean the ignition switch, I was getting similar issues & that fixed it. Not the barrel, but go in from underneath by drilling/knocking out the two blind bolts & you'll find the switch. It'll be manky, gooey, sludgey & horrid as everything in the lock dribbles down & collects there. I just wiped mine down, cleaned it with contact cleaner, gave it a smear of silicon electrical contact grease & refitted it.

As for the fast idle, check the TPS & SPS (as the ECU uses the offset of them to know when the STV motor is in the fast idle position). STVS is the secondary throttle valves, the motor turns backwards to push on the fast idle cam, you should be able to see it do this looking down near the throttle cables with the tank off. If that doesn't solve it then someone has fiddled with the fast idle screw that should never been adjusted, it's trial & error to get that back where it belongs so don't go there if you can help it.

Title: Re: Starting/Priming
Post by: Simonic on Thursday, 11 March 2021, 11:08 PM
Thanks @Hooli . I never thought it could be connected to the ignition switch or i would have mentioned that i replaced it with a brand new Suzuki one three years ago... The bike has done maybe 2k since then so it may not be the culprit but i'll check it anyway.

I'll also have a look at the fast idle from your description.
When i bought the bike it seemed to have a caring owner who polished it to death and then an enthusiastic amateur who shouldn't have been allowed tools.... maybe it's down to him
Title: Re: Starting/Priming
Post by: Hooli on Thursday, 11 March 2021, 11:18 PM
In that case, the mutliplug to the pump & the grey multiplugs under the LH side cover. I can't see a switch going wrong that quick. Oh & the multiplugs in the headlight bowl where the ignition switch plugs in.

I had an earth lead snap under the tank in the past, everything still working as it earthed through the mounting bolts but obviously it wasn't ideal.

I've just recalled you said you did the teabag, it could be worth popping the pump out the tank to check the connections in there too. It has to be a crappy intermittent connection somewhere really.
Title: Re: Starting/Priming
Post by: Simonic on Friday, 12 March 2021, 12:59 AM
Thanks Hooli. I'm going for a look now.
Title: Re: Starting/Priming
Post by: Simonic on Friday, 12 March 2021, 03:08 AM
So. I've now had a look. I tried to start the bike before i took anything apart and it did as i described before and went thru a half(ish) cycle of priming and then gave the F1 light. The only thing that i noticed was that the hp fuel filter was only part full and after the third attempt when it was full the bike would then start.
Anyway i checked all the connectors suggested and although they all seemed ok,you never know.The wires are a bit tight in the headlight as it's non-std (bandit12)so i tried to route them better too.
The thing with the fuel filter got me thinking tho..... Is it possible that because the filter was only part full that the prime function which was filling the filter should have been 'seen' by a sensor somewhere as as no fuel pressure was going to the rail that this caused the error code?.
I'm not sure. Anyway it's working now so i'll see how it goes.
I'd like to thank you Hooli for your help today
Title: Re: Starting/Priming
Post by: Hooli on Friday, 12 March 2021, 07:36 AM
Pleasure, the filter being part full sounds odd to me. I wouldn't expect air in the fuel line after the pump, could there be a slight leak somewhere that's letting it drain when parked?

Does it happen when parked for a bit or  every time you start it?
Title: Re: Starting/Priming
Post by: Eric GSX1400K3 on Friday, 12 March 2021, 09:38 AM
+1  to Hooli for his advice  :clapping:

Might need to pull the pump out and do a flow check?  Could be a dodgy pump, or also try removing the aftermarket inline hp filter, this could be causing a flow restriction preventing the pump from priming properly.
Title: Re: Starting/Priming
Post by: gsxbarmy on Friday, 12 March 2021, 05:31 PM
Could it be the fuel pipes themselves need replacing? They are supposed to be changed (from memory) every 5 years (may be less), I'll bet most have never been changed, and 14's now are starting to age on a bit, let's be honest, so always possible that original OEM fuel lines could have hardened or started to crack maybe?
Title: Re: Starting/Priming
Post by: grog on Friday, 12 March 2021, 06:29 PM
Hoses are easy to update. 8mm. 5/16 th EFI hose. Original connectors can be cut out of original hoses, refit into new hose with proper EFI worm drive clamps. DO NOT use normal clamps.
Title: Re: Starting/Priming
Post by: Simonic on Friday, 12 March 2021, 08:37 PM
Quote

Does it happen when parked for a bit or  every time you start it?
After it's been parked for a bit.
Title: Re: Starting/Priming
Post by: Simonic on Friday, 12 March 2021, 08:42 PM
Thanks to everyone else who has chimed in. The HP filter is new. I did the HP bypass mod years ago and since then i've used either a Wix Wf8127 or a Baldwin Bf1160.
The fuel lines are also new using correct sized fuel line onto the factory couplings.
I'm not sure how to do a flow check on the pump but i'd be willing to give it a go if one of you can explain what i need to do but i can confirm it is one of the Hi-Flow pumps which is 2 years old.
Thank You All
Title: Re: Starting/Priming
Post by: Hooli on Saturday, 13 March 2021, 12:40 AM
Hotwire it with 12v & see how much comes out.

I can't remember the figures, but you can get the factory workshop manual from the download section of this site & it's in there. Off the top of my head, 1,200ml in 30secs.

I'd be looking for a leak somewhere, or a bit of perished pipe etc as it sounds like the feed to the rail is loosing fuel when parked.
Title: Re: Starting/Priming
Post by: Hooli on Saturday, 13 March 2021, 02:41 AM
Thinking about it a bit more, it could be a leak inside the tank after the pump letting the pressure out when the bike isn't running. You'd see no evidence of a leak then, but it'd allow the pipe work after the pump to drain. I had similar with the output flange of the high pressure pump spilt years ago.
Title: Re: Starting/Priming
Post by: grog on Saturday, 13 March 2021, 06:38 PM
Simonic, youve changed pumps etc. Not a faulty or mis aligned O ring inside tank.
Title: Re: Starting/Priming
Post by: Simonic on Monday, 15 March 2021, 08:16 AM
Thank You to both you guys.
It sounds like i'm going into the tank again then !!
I'll check the manual Hooli to see how much flow i should have and i will also check all the seals too Grog.
One thing i recall from when i fitted the Hi-FLo pump is that the flo rate is adjustable from the side of the pump. When fitted it was set at the half way position. perhaps i may need to up the flow.
I'll have a look and get back to you. :cheers:
Title: Re: Starting/Priming
Post by: Simonic on Friday, 09 April 2021, 10:00 PM
Hi Gents.
I've had the pump back out again now and rigged up bit of jig to test the flow. I went with the flow rate of 1.2 as supplied by @Hooli . near as i could see this was about right,maybe a bit topside if anything. I had a look at the flow adjuster on the pump and it was set to the half way mark. I put it all back together with a new HP filter(i used the baldwin one this time)and so far its been ok. So,i don't appear to have found anything but it's working at the moment.... Fingers crossed and a Big Thank You all for your help  :cheers: