Bronco II BOG & acceleration issue

[Travis d]

What's up guys new here looking for some help with a intermittent problem iv been having with my 87 bronco II 2.9 manual transmission.

It runs great other than one problem that I can't figure out. While driving sometimes the truck will start to hesitate and as I give it gas it's starts to bog and will not accelerate but iv figured out how to get it to snap right back to normal while it's happening.

For example if im cruising and it starts to bog and stop accelerating while I seem to be rolling to a stall if I quickly turn the ignition off and then back on real quick it will backfire one time and it's back in action as if nothing is wrong. And I can do this every time it happens and it snaps right back never fails one back fire everytime and back in business. It's really strange.

I'm assuming this is something common hopefully a easy fix ?? Maybe a sensor or egr valve?
That's for any help!!.

 

[kaidenshi]

Check your inertia switch. It's designed to cut power to the fuel pump(s) if it detects a rollover, but they fail way too easily and start "detecting" every little bump in the road. Quick fix is to disconnect it and short the connector in the cable. I cut mine off and shorted the wires with a wire nut and electrical tape. Haven't had a fuel cut off since.

You can find it in the passenger side footwell under the carpet and against the firewall. It's a small black box with a two-wire connector.

 

[wildbill23c]

Check your inertia switch. It's designed to cut power to the fuel pump(s) if it detects a rollover, but they fail way too easily and start "detecting" every little bump in the road. Quick fix is to disconnect it and short the connector in the cable. I cut mine off and shorted the wires with a wire nut and electrical tape. Haven't had a fuel cut off since.

You can find it in the passenger side footwell under the carpet and against the firewall. It's a small black box with a two-wire connector.

HAHA, yep, except turning off the ignition switch and back on will not reset the inertia switch so there's something else going on.

 

[kaidenshi]

HAHA, yep, except turning off the ignition switch and back on will not reset the inertia switch so there's something else going on.

No, but it primes the pumps long enough to go another half mile or so. I went through that song and dance until I found the issue. Also, if his switch hasn’t completely failed yet, if it’s just a bad connection inside and not actually popping via the ball, it could be making contact again intermittently between engine restarts. That’s exactly how mine failed, the connector had gotten corroded and was randomly disconnecting power to the pumps. I could go a week with no issues and another week of constant engine restarts while driving. Shorting the connector was a permanent fix for me.

 

[Locotomb]

A faulty Switch wont necessarily trip, but can short your system. Resulting in a necessary restart.