| Author | Message | ||
     Buellx1w |
Read Part I first. If you DON'T have fuel pressure, this part will help you diagnose that. The fuel supply system contains the fuel tank, screen, fuel pump, fuel pressure regulator, petcock, fuel lines, and inline fuel filter. What can cause low pressure? Basically 1 of 3 things: 1. you HAVE pressure, but something is blocking it from reaching the injectors 2. you HAVE pressure but it's ESCAPING before it reaches the injectors, or 3. You don't have pressure. Work backwards from the injector line. Re-attach it. Now disconnect the line from the intake of the inline filter and check pressure there. If you have it there, either a fuel line is blocked (very unlikely) or the inline filter is blocked. To check the filter simply take it out of the circuit- connect the intake and output lines directly with a properly sized fuel line connector, clamp it and see if it starts. If it does you may have a clogged filter. If the filter is ok you can try to replace lines or possibly try to blow out the fuel rail with an air gun. But its unlikely anything large enough to clog the like could reach the post-filter rail. If you DONT have pressure on the intake of the inline filter, you may have a fuel pump problem or possibly a control circuit problem. If you don't hear the pump whirrrr a few seconds, when you turn the key it could be the pump, or even the ECM not sending the signal to the fuel pump, or possibly wiring. Your service manual has a detailed flowchart telling you what voltages you should measure at various times. If you hear no WHIRR, and the voltages look right, you most likely have a fuel pump problem. In the next part I'll explain how to diaanose that..  | ||
| 01x1buell |
how about checking the relays first before anything else if no fuel pump noise.. what about that .... always start simple . | ||
| Greg_cifu |
Well, it would have been nice if you had kept all these posts in a single thread. Half of the Old School forum is your daily updates and it's very hard to follow all the progress. As I suggested earlier, the o-rings on the fuel pump assembly were worth checking out. Now that you've posted a picture, that's very similar to the construction of the one on my Excelsior Henderson. Lemme guess: one or two O rings on the snout of the fuel pump and there should be two different sizes on the regulator. On mine, the alcohol had eaten both sets of o-rings and it was puking fuel out of both regions. Result? No fuel pressure. I replaced them and all has been good since. |
