please help

[b52 bomber]

i took the motor out to rebuild it got it back put it in ,wouldnt fire did nothing but spin over, got to tracing things out its got fire, and got fuel through the filter and pump but not through the injector, just wondering if anyone has had trouble with the injector going out, or if anyone has had this problem, if you pour a small cup full of gas through the throttle body it DOES FIRE but cuts off within 3 seconds , any sugestions

[QUADSQUAD7]

Your going to have to be more descriptive and make more since.

[b52 bomber]

ok, i pulled the motor, got it rebuilt, took about 5 weeks, got it back put it back it in, didnt unplug anything from the throttle body at all just it from the intake on the motor side ,hooked everything back the way it was. went to fire it up, did nothing but spun over, no fire. so i started checking everything starting with the spark plug it was brand new, so i started tracing the fuel lines to make sure it was getting fuel. i was getting a full stream through the line comming from the tank through the filter, so i unhooked the line from the pump up and turned the key on which powers the pump i had fuel pumming through there. so i called cernics racing they said it was either the pump the injector, timming , or my error, ok well he said it was very unlikely the pump, and obviously i got when i turned the key so that eliminated the pump,so i called the guy that built the motor he was sure that it was right ,,so i poured a cap full of gas through the throttle body to see if it was problem in the injector well it fired and ran smoothly for about 2-3 seconds and cut off. so ipulled the throttle body and cleaned the injector with carb cleaner no better but its not pumping fuel through the injector at all...so my knowledge tells me its either the injector,the cdi???,or the plug , the plug is tight, i didnt unplug the cdi at all so i dont know how that would mess with it unless it resets or something after a period of time being unhooked from the battery, so,,,,,,,,,,,,bad injector ????? im have no clue never had it happen before

[QUADSQUAD7]

First, I would unhook the fuel line coming out of the regulator on the bottom of the tank. (the line going to the injector) Turn the key on and if fuel is coming out then your good there.

You could possibly have a bad connection to your injector. Remove the plug and make sure there are no obstructions and both the plug and injector prongs are undamaged. Plug back in and see what you got.


To eliminate the plug: pull the plug out of the head and put it into the plug wire. Allow the plug to rest against bare metal on the bike and try starting the bike. (you don't need any fuel) If the plug is sparking then its good and no problem there. I dought its the plug if it fired already.

Since you had someone else do the motor work you can be for sure what he might of unpluged or messed with. If you can't figure it out take it back to him and see if he will make it right. I build motors and know quite a few guys who build them and I've never known a bike to leave a shop without test running the motor after build.

If you've tried all these and no luck take it to a dealer who can run diagnostics on your ecm and test your injector output.

Good luck.

[b52 bomber]

the spark plug is brand new and like you said firing,(eliminated)i pulled the motor myself , and never removed the plug going to the sensor at all..(eliminated) Ive got fuel from the regulator(eliminated) ive got fuel all the way to the injector , but no fuel through it, so im down to 2 things 1, the fuel pump has gone out and not allowing enough psi to open the injector which was fine when i took it out, or the injector is bad or stopped up .and i sprayied carb cleaner in it and it didnt help so. am i on the right track so far on the idea of a bad injector or is there anything else that i may be missing . To try to make it easier everything is firing and working but the injector its not spraying at all so thats how i came up with the 2 things pump not putting enough psi to open it or injector is bad.

Thanks for all your help.

[ltrracer]

i have had an injector go bad on me twice now, it just kept trying to fire but would just keep cranking and cranking, if i sprayed starting fluid in the throttle body it would fire up for a second or two then shut off so i had to replace my injector and it fired right up, luckily i had a spare laying around

[Speed_MDS2]

I've got a stock injector that I'll sell ya. Let me research a price and I'll get back with ya this evening.

[b52 bomber]

got it fixed, the wiring harness for the yosh pim wasnt sending a signal