HELP ME!!!!!!!!!

[Doug Heim]

Well I took 1/2 day at work today as this was really bothering me and I knew if I needed to get parts, that time was critical. I did arrange for an ECU to be deliverd to me and Ill still see that tomorrow but now I dont need it. I do have another RC51 Motor that needs one for future use so it is not a waste.

I really thought it was a simple ground issue so I removed every connection to ground and scraped down to bare metal and even ran a few extra wires including a hard wire from the battery to the Engine. Same problem.

I again checked fuses, all conections, relays, and safteycut outs. All good so I called and got the ECU comming.

Staring at my wiring diagram I decided to check power from the saftey relay to all the components that it suplied power to. At the same time, I was taking ohms readings at all sensors and electrical components advised from Fabr. During this process, one of the components that the saftey relay suplied power to was the injectors. There is a good size plug that houses all the wiring going to the throttle bodies, injectors and throttle position sensor. I was going to check power and continuity at this point but noticed that one of the negative supply lines from the ECU to one of the 4 injectors was loose from the plug. I pushed it in and violia!

Now someone want to tell me why it is that an uncompleted circuit to the injector would lock out spark and the fuel pump? I would think that the injector itself and alone would be affected. Anyway, That fixed it. I pulled the connection out and added a dab of super glue so it does never come out again. What goes on in that ECU is a complete mystery. It is even worse that the dealer service center cant even test wether the ECU is good or not 

Thanks for your help guys!

[Yummi]

Everybody knows that the flux capacitor requires 1.21 gigawatts of electrical power to operate.  The steel body of the buggy has a direct and influential effect on the "flux dispersal."

You should have looked there first.

[Nutz4sand]

I might understand where a non firing injector on a TWO stroke might shut the motor down but even with oil injection the cylinder should not burn up.

Good question as to why it would shut a fourstroke down?

Seems the puter should warn the driver of the issue and stay running on the other(s) to get you home/garage/safety etc. 

[fabr]

One would think that it would go into "limp home" mode anyway. Oh well glad to hear you got my ride running!

[thedoctor]

Yummi, Don't try to steal my lines. I am "The Doctor". Tim

[artie on edge]

Yeah, seriously Doug...why didnt you go straight to that connector? When I was reading your post I was thinking..I bet that connector is open circuited...pretty obvious really.... at least down here in Aus.....

 

[fabr]

 

[Doug Heim]

 

I bet you could even see it from down there huh?

All in all I think if the injector did not work properly that the motor would still run limp. Remember this was a broken connection, not a bad injector. Each cylinder has 2 injectors on this motor. Still wonder why a bad connection to he injector would disable the whole fuel and firing system. Stupid!

Must be an engineer's idea. (sorry in advance to my engineer friends) 

[boltz2012]

just an idea to the mystery. You say it has two injectors per piston right? Well If it fired and ran with one of the injectors not firing at all and one pumping a normal stream of fuel into the piston you would run that piston really leann Unlike on a motor that only has one injector. It just wouldnt fire in that hole. I dont think it would detonate but it could gald the hole causeing the cylinder to over heat and therefore swell and the piston would be sloppy in the hole. Thus causing major problems if it fired and you was to continue driving it. Just my two cents on it. I guess a limp mode should disable the other injector so that hole doesnt fire at all.

[SPEC]

Yeah, seriously Doug...why didnt you go straight to that connector? When I was reading your post I was thinking..I bet that connector is open circuited...pretty obvious really.... at least down here in Aus.....

 

Artie your toilet swirls backwards

[fabr]

just an idea to the mystery. You say it has two injectors per piston right? Well If it fired and ran with one of the injectors not firing at all and one pumping a normal stream of fuel into the piston you would run that piston really leann Unlike on a motor that only has one injector. It just wouldnt fire in that hole. I dont think it would detonate but it could gald the hole causeing the cylinder to over heat and therefore swell and the piston would be sloppy in the hole. Thus causing major problems if it fired and you was to continue driving it. Just my two cents on it. I guess a limp mode should disable the other injector so that hole doesnt fire at all.

I agree.

[artie on edge]

so?

[Nutz4sand]

I did not think about the other injector still firing causing a lean condition.

GOOD CALL Boltz I too would agree this sounds the most logical.

I agree on the limp home it could just cut both injectors or maybe cut all the injectors IF it was the high speed (secondary) injectors then just run home slowish on the primary injectors.

Course if it was the primary injector that was disconnected would it run only on the secondary injectors at low RPM?

[Doug Heim]

Boltz I agree too. Just another way to protect the motor. Would be nice if you could get a code showing thats the problem though. 

[fabr]

Anything more to add now Artie?