rrp0968

What does fuel injector pulse duration have to do with the fuel pump?

SoonerLS

The injectors are also on the circuit going through fuse #27.

jhanna

Rnlcomp, what is the injector pulse width for the different engines?

Ssls6

I think the problem is different. I've watched the fuse 27 thing for several years and two things stick out to me.

1) most people find the problem when trying to start their truck. You don't hear about people driving down the road and the motor dies (or at least not very often)

2) heat (melting) damage has been shown on many fuses but the fuses were not blown. That says the amperage was below the 20A limit.

If you look at the fuse holder, there are two points that make contact to one blade of the fuse. The resistance of that arrangement must be somewhat high so enough heat can be generated by the I2R. Starting the vehicle must cause the current to be sustained long enough for the temp to rise....pressuring the fuel rails. Ford says it is a V8 problem but I bet it is a "non-direct injection" problem. The direct injection motors "eco boost" must use a different system "two stage?".

My 2 cents......FWIW, if injector pulse width was important then MPG would be important and towing should kill the fuse.

jhanna

^ have to disagree on your first point, I've read many post, here and other forums, where failures did occur whiling driving and/or on the highway, requiring a tow truck. This is what scared the he!! Out of me. A failure in the driveway isn't bad, but on a deserted highway at 3am or with wife or daughter driving.

Agree with second point, current draw less than amount to blow fuse but fuse contact/socket surface area can't handle the load and is a "resistive point" which gets hot and melts.

SoonerLS

I haven't looked at the part #s, but the EB35 calls for much higher fuel pressure (~80psi vs ~50psi for the 3.7/5.0/6.2), so they must be doing something different.

Missmy06

The EB has a mechanical engine driven fuel pump that bumps up the fuel pressure to the injectors. Its operation is very similar to a common rail diesel engine.

Moose-Man

[Just wondering after relocation kit put in, do I need to put fuse back in #27 slot? Just left Big O after do relocation kit and I do not have a fuse in slot #27. SPOILER][/SPOILER]

Spiky

No. If you do the relocate, you will not have a wire in 27 slot. I guess.....you could store one there.

Moose-Man

Thank you Spiky! After seeing the video posted, I see fuse is relocated to slot #70. Big O forgot to mention that to me, but they did do it for around $160. Seemed like a pain to do myself. My miles to empty continues to be whacky. I have 82,000 2014, but didn't seem to fluctuate until this issue with the fuse? Anybody have more of an answer than what I've briefly read on here? Thx!