pcmhacking.net

so lets introduce some discussion about this guys wiring and engine management. I could be wrong and it might be something else but as hes lying there in a burning car, I can hear a fuel pump running and liquid splashing around.... what sort of moron hooks their fuel pump up to the ignition switch instead of the PCM??? this is exactly the sort of reason you would want the fuel pump to stop in a crash like this.

Wow! Crazy jump but yeah that fuel pump still running is a bit of a worry. No reason you cant have a switch for fuel pressure and leak testing with the engine off but have the relay PCM switched during normal running. Until you experience a fuel fire I dont think people realise just how quickly shit happens.

experienced a fuel fire without the engine running. fire extinguisher did nothing, got the hose and by then half the car burnt down and had LPG tank half full too.

man that was scary! didn't matter much as it was just a ford. But makes you take the fuel system and any leaks very seriously.

yeah I've seen a few conversions the same, just wired the relay for fuel pump to the ignition ....

I too have experienced a fuel fire, luckily only minor, and it sure gets the heart racing, I was able to pour water over this one and it at least moved it from the engine bay to the ground where it went out pretty quickly, still its not the sort of thing you want to have to deal with at all, let alone while trying to evac someone from a car!

hes very lucky he was even able to get out by himself at all after that wild ride! often in these sorts of crashes the driver is knocked out or broken back etc so they need to get them out as well as worrying about a fire!

I don't know what sort of rules they have to abide by, my guess for something like that there are none, its your life if you want to risk it go ahead ... but I know in most racing classes you need some sort of external battery isolator which "should" remove all power from everything past it to the entire car.

and one would think with a 1000hp motor in a custom built car that you would have the smarts in it to be able to control the fuel pump from the ecm or at least some sort of oil pressure sensor or similar.

on a side note, I was interested to know, if revving or braking the engine in this situation is the same as on a motorbike. I know with the motorbike you can rev it in the air or brake the wheels to effect the rotation of the bike up or down in the front etc to help with landings, but not sure if its relevant to cars ? because it did seem like it was fine halfway then just all of a sudden nose dived! Guess it could be a cross wind or aerodynamics too ?!?!

yeh no excuse really.

I remember a similar issue where there was a bug with a airbag system and if activated didn't shut off the injectors. Was fixed pretty quick by GM.

Yeah thats crazy. You'd think with that kind of budget and probably a team of engineers they could do better than that! Not that you need a team of engineers or a budget to just wire it properly. Pretty high stakes too. I wonder if they even noticed after the fact! I'll stick with my delco controlling the fuel pumps, thanks.

just one of the MANY reasons why the delco (and im sure other factory ECMS) are the business for conversions over an after market unit!!

Most aftermarket ecus (actually all that i can think off) control the fuel pump too, so there really is no excuse!