Fuel problems? Bypass fuel relay switch...

[74project]

In case anyone is having a problem with fuel delivery like I was, cut it out and go straight off the ignition. I had a fuel issue off and on for a year. No one could figure it out even the computer. I changed fuel pump, filter, and programmed and reprogrammed the ecu till finally getting rid of the fuel relay on my wire harness from street and performance. It runs like a dream everyday for the last 4 months. Hope it helps.
Posted via Mobile Device
Posted via Mobile Device
Posted via Mobile Device

[ls1nova71]

So the pump runs the whole time the ignition is on? That's not the safest method, and is why the factory lets the PCM control the fuel. If you're involved in a wreck, and a line gets broken, it will continue to pump fuel at a rate of 58 PSI, now if it's spraying on something that is on fire, you've got big problems. And that's if you're conscious, if you're knocked out, well you do the math. I hope you at least have an inertia switch like alot of Fords use to aleviate the situation to some degree.

It seems to me that you either had a wiring problem, or the driver in the PCM was acting up, which shouldn't have been too hard to track down and fix.

[BR3W CITY]

This type of thing has been brought up in a number of threads; and usually when the pcm gets grumpy about the fuel cutoff, there IS often a mechanical problem causing it. A bad ground, small gauge wire, or an overheating fuel pump (too much draw or restriction) can all cause the pcm to do this. Before disabling the control completely, finding the actual problem is usually a good idea.
Keeping it on the PCM, but using the pcm to trigger a heavier duty relay and a larger gauge hotwire from a 12v source will allow you to run FULL voltage (no pcm voltage drop) to the fuel pump at all times, meaning that your fuel pressure will be constant, but you still have a measure of safety....and I'm not really a "safety first" kind of guy.