RC51 Forums banner

1 - 20 of 26 Posts

·
Premium Member
Joined
·
346 Posts
Discussion Starter #1
Hi Folks,

Just getting to the end of a long rebuild on my SP1 and finally ready to flash it up but it won't start. It turns over and tries but it won't run at all.

It has a new fully charged battery, good spark, and the fuel pump is running. The bike has been off the road for 5 years, but was running before it was pulled apart.

I have checked everything I can check, and there is no FI light or fault codes.

The bike cranks over and tries to fire but won't.

I had a spare FPR so swapped that out; no difference.

The only thing I can't check is the ECU.

Any help/suggestions gratefully received.

Thanks,


Guy
 

·
Premium Member
Joined
·
346 Posts
Discussion Starter #3
Turns over fine, and fires occasionally but only briefly. Plenty of fuel to the injectors.

Thanks
 

·
Premium Member
Joined
·
346 Posts
Discussion Starter #5
Good call but unfortunately doesn't apply to mine as I have a really nice strong spark at both plugs.

I am really hoping a local RC owner will let me try my ECU on their bike, to confirm it is/isn't good before I go deeper.

My gut feeling is an issue with the throttle bodies I replaced as everything else on the bike is as it was when it was stripped. All things being equal, if all other components were known good prior to the strip, and the only part not original is the throttle bodies/injectors/tps etc then although the FI light would suggest nothing wrong, they are the only parts untested.

I am planning to replace the injectors/tps etc with the original ones this weekend, which effectively puts the bike back to how it was prior to the strip down.

It's so frustrating to be this close to getting back on after all this time and not being able to start it!


Thanks for all the suggestions, pleas keep them coming,


Guy
 

·
Premium Member
Joined
·
346 Posts
Discussion Starter #7
They came off Ebay and were listed as SP1, but to be honest I didn't compare them to the originals and they went straight on without issue, would SP2 throttles/injectors stop it starting? I figured even if they were SP2 it would start just run badly? Could this be the issue?

Thanks.
 

·
Premium Member
Joined
·
346 Posts
Discussion Starter #9
Not sprayed starting fluid in (don't like the stuff), yes I am pulling the choke and no kinks in the fuel line.

There is definitely fuel coming through the injectors as it does try to fire, It has to be a fuelling issue, but the question is what is causing it.
 

·
Registered
Joined
·
382 Posts
Well you may not like the stuff, but you would know in an instant if it was a fuel issue, or something else like the module or even fuel pressure. nobody says you have to run the bike on it. you just need to see if it will start and run for 15 seconds.
 

·
Premium Member
Joined
·
346 Posts
Discussion Starter #11
Already know it's a fuel issue as I have a good spark.

Did some more testing this evening, and it appears to be an ECU fault.

The injectors have a constant resistance on the earth to the ECU, same for all injectors (bit strange), but the harness tests okay for all injectors. As the earth's are switched by the ECU I guess I am looking at an ECU fault.

Next job is to find someone local an willing to let me test my ECU on their RC.

Can't really see what else it could be as all four injectors have a common earth within the ECU, switch via the injector drivers.

Anyone else with other possibilities?

Thanks,


Guy
 

·
Premium Member
Joined
·
8,335 Posts
If you have installed SP2 bodies on your SP1 you will need to change other things too like a wire harenss and the ECU to boot.

Do a search here as I have not done this swap before...I am just talking off recall right now.
 

·
Premium Member
Joined
·
346 Posts
Discussion Starter #13
Checked tonight they are SP1 throttle bodies, would have been great if it had been down to them as I could have sent them back.

The problem is looking like the ECU, as I cannot see any other reason for a resistance on all the injector drivers/earth's.

Just trying to find someone local to try my ECU out on a known good bike.


Guy
 

·
Premium Member
Joined
·
346 Posts
Discussion Starter #16
Good luck considering you haven't put a location in your profile.
Shouldn't be a problem as I am looking for someone local on my local bike forum, but as most of the guys on here have loads of experience on the RC, it is the best place for advice. But thanks for pointing out my omission I will update my profile, but I doubt I will find anyone on here from Cornwall in the UK, happy to be proved wrong though.

Thanks,


Guy
 

·
Registered
Joined
·
729 Posts
I have seen many threads where people talk about the "choke", for the record the choke is simply a fast idle, the richening of the mixture is taken care of by the sensors and ECU.
I threw the cable away years ago, equivalent weight saving of £50 worth of Ti bolts
 
1 - 20 of 26 Posts
Top