Greetings, new around here. I’m a fleet maintenance tech for a large manufacturing corporation working at a large factory/air field. I’m an auto tech converting over to Material Handling Equipment. I got a Genie Z-60/34 I have been chasing my tail on. It fires, runs great for a couple of seconds then dies. Finally got the company to buy the diagnostic equipment for the ford 2.5L in it and all we get is a code for fuel pump voltage low. Kicker is, these are normally dual fuel but this specific environment ordered them propane only and therefore does not have a fuel pump. It seems as if the low voltage reading is issuing a kill command. My question is does anybody have any experience with this and how are they tricking the ECM into thinking they have voltage at the fuel pump when it doesn’t exist because that seems to be where the problem is. Thanks
Hi, check alternator/system voltage. Either too high or too low will trigger your problem.
Ironically after posting this and doing some wire tracing we found that the way Genie got around this issue was to jump the ignition voltage to the fuel pump circuit to provide the necessary voltage to the ECM and make it believe the fuel pump circuit was fine. We had found that jumper wire was lose at the control box previously by just stumbling on it and fixed it. At the time didn't know what it was to just that it was clearly supposed to be in the control box and was lose and having bad contact so that appeared to be the original issue. The second issue is that multiple attempts at starting during diagnosis after doing some part swaps (Initially we didn't have the tool to pull the ECM codes so we were just hot swapping things in an attempt to find what was causing the kill command. Crank position sensor etc) had left the battery sitting at around 11 volts. It was enough to engage the starter and start the system but not enough of a voltage to keep the ECM happy on the fuel pump circuit. And the system seemed to kill itself before the alternator could provide enough voltage to off set itself. Also found the alternator only charging at about 12v instead of 13.5 or more. So we have ordered a new alternator and brought the battery back to the shop to charge. Hopefully this will correct our issue. Such a silly thing because the environment that we work (Airfield) doesn't want loose fuel being carted around and only wants sealed propane cylinders and therefore Genie did a back yard mechanic jumper that isn't in any of their manuals.... Atleast this place pays well. I'll update if this fixed it or not.
I don't know what version your machine is as the 60/34 is a long series with many changes over the years, but open the lower control box and see if it has the ignition/start module, small black box with LED lights on it. If you have that module, once the engine starts it needs to see a tach signal from the alternator and light up LED #2, if it doesn't light up LED #2 once engine starts it will kill the engine after about 3 seconds.
Thank you, by my understanding it receives that RPM signal from the alternator as the Ford ECM doesn't provide it to the Genie controller correct? If that is the case, we already swapped an alternator from a working one to test that exact theory. I didn't however know about the black box so ty again for that.
Again, I don't know what series your machine is so I can't see your schematic. The Ford engine ECU only controls the engine, it's independent, or I guess more correct to say, it's not married to the Genie controls. Older Genie machines used the ignition/start module, newer machines may not have that, but I haven't worked on late model machines so I don't know about that. This is what the ignition/start module looks like, typically located inside the lower control box. > https://www.ebay.com/itm/3260502748...1291&msclkid=84d63bf717fd175d3fbe5d4b1d5e4939
Awesome. Thanks. I'll look at it tomorrow.