starting problem

[90bronco86]

On my 1990 bronco 351 w it has a bad habit of starting and running fine for a while and then not starting, i thought it was the ground from the battery to the radiator suppoort because it melted, but after I replaced it with a thicker wire to a better ground it still got too hot to touch and I had an incident where she wouldn't start and I had to put another ground on. Now it starts every time but it just dosent seem right. And on occasion it will kinda shake while its idling. And it has no acceleration at all, I have an 86 with a 302 and the same gears and trans as my 90 with a 351 and the 86 just kills it in speed.

 

[miesk5]

yo 90bronco86,

Since that ground was still hot, inspect others and look closely @ the wire strands and ensure there is no corrosion between each strand as well as between the strand to the clamps or eyelets to ground; do same for Positive cables and strands to starter relay and starter.

Voltage measured at the starter during cranking should always be above 9.5V DC

Some run a seperate ground from a starter bolt to frame where battery ground is attached. Also check the starter relay; it's ground path is it's body to inner fender; so make sure the relay is mounted tightly to a rust/grime free area.

Here are the Grounds in your 90;

G101, G102 Location Diagram in a 90

Source: by SeattleFSB (Seattle FSB) at http://www.supermotors.net/registry/media/851827

G401 Location in Frame Rail Diagram in a 90

Source: by Seattle FSB (SeattleFSB) at http://www.supermotors.net/registry/media/860021

G102, G105, G107, G108 Location Diagram, Engine Area in a 90

Source: by Seattle FSB (SeattleFSB) at https://www.supermotors.net/registry/media/860022

G201, G205 Location Diagram, Behind Dash in a 90

Source: by Seattle FSB (SeattleFSB) at https://www.supermotors.net/registry/media/860017

G500 Location in Full Body Diagram in a 90

Source: by Seattle FSB (SeattleFSB) at https://www.supermotors.net/registry/media/860018

G701 Behind Instrument Panel near RH side of Radio, Tailgate Ground "..."For ~'90-96, in the driver's kick with several other grounds. Look for the green screws with a BUNCH of black wires; Ryan M (FireGuy50) wrote, 1986..."

Location Diagrams, Engine Area in a 90 from Ford EVTM

Source: by SeattleFSB (Seattle FSB) at https://www.supermotors.net/registry/20487/76450

Location pics in a 90 5.8; passenger side frame; braided strap near O2 sensor; near + battery post on fender apron; on engine

Source: by Seattle FSB (SeattleFSB) at http://www.supermotors.net/registry/20487/78002

Next is a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19

The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test.

Run it around to heat the engine up and shift thru all gears incl Reverse. Then turn off all accessories/lights, etc.

Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch.

Do Key On Engine Off (KOEO) portion first.

Look Codes up in my broncolinks.com site using the new Search function.

And Post em here according to:

KOEO

&

KOER

 

[90bronco86]

i figured out the problem, it was the ground that went from the frame to the block, i replaced it and i haven't had a problem since. thanks for all the help