1985 f150 running issue while driving

[kyleroth48625]

The gauge shouldn't be able to work unless you swapped senders.

Bullnose to later trucks have completely different scales and read in reverse as well.

Supply should be 3/8", return 5/16.

The sending unit themselves are mounted on the opposite side and swing in the other direction that's why it's upside down if you put it on a carbed sender if it's on the efi sender it swing the right way to read right there the same ohm

 

[ArdWrknTrk]

The sending unit themselves are mounted on the opposite side and swing in the other direction that's why it's upside down if you put it on a carbed sender if it's on the efi sender it swing the right way to read right there the same ohm

I'm sorry, you are very wrong.

A Bullnose trucks sender and gauge read 70-10 ohms.

A Bricknose (or later) truck reads 16- 160 ohms.

I don't know who told you that, but they are full of *

[Kmwadejr]

Are you saying the timing jumps around with the sprout pulled?

If so the only thing I can see to cause that would be a timing chain with a lot of play.

Easy to check for play. Turn the motor by hand and set to TDC, do not turn it back to line it up perfect.

Now pop the dist. cap and keep an eye on the rotor, turn the motor backwards till the rotor just starts to turn and stop. Hope the rotor did not turn much, now look at the timing mark and you should be able to tell how many degrees it moved and will show the play.

I would say 5* is pushing it on play.

BTW you said plugs & wires how about the cap & rotor.

Dave ----

Change your cap and rotor