Missing and Dying

[smaug6]

I have an 86 2.9L Bronco II 4x4 which has started dying and missing as I drive usually at highway speeds. Any ideas about what causes this would be appreciated. :icon_confused:

 

[hopster]

I just experienced this on my truck I hooked up a fuel pressure gauge and noticed the fuel pressure dropping. that would be a good place to start. If that doesnt work check your ignition system.

 

[thunderbuggy]

I had a similar problem w/my 86. I am an idiot so I did what we usually do and just started replacing parts. I started with the tfi module, then the high pressure fuel pump under the D/S frame rail and it turns out I overlooked a simple little wire that hooks up to the battery terminal. IT was frayed and nasty and only had two wires intact inside the casing so when it was wiggled just right it would run fine then when I hit a bump or crossed an intersection it would either just die, or miss and then die. As I was cussing and leaning in to try and find the problem I would lay an elbow or something on the wire which would make it connect back up and then the next time I hit the key, the damn thing would fire. It cost me much more than just a wire to finally figure it out but hey, I now have a sh*tload of new parts on it that will not go bad for a while.