1990 bronco 5.0 starting issues
Thread Starter
|
New User
Joined: Mar 2020
Posts: 1
Likes: 0
1990 bronco 5.0 starting issues
So my bronco died in an intersection and upon a quick look over i didnt hear my fuel pump. So i replaced it and the fuel sending unit and the fuel filter. And when hooked up to a direct power source they pump perfectly. I put it into the truck and nothing. So i replaced both the fuel pump relay and fuel injector relay and still nothing. It doesnt even prime the fuel pump. I jumped the fuel pump relay and it got the pump going and i have pressure in the rail. But when the relay is put back in place nothing. I have ignition, i tested it by spraying starter fluid down the intake and it cranked as long as i was applying that. So im not sure why the motor aint starting. My only guess is the engine control module is bad? Because the pump relay isnt activating and neither is the injector relay which are both controlled by the ecm? Any ideas help here. Wether yall think its that or if its something im overlooking. I also checked the inertia switch which hasnt popped so its not that. Both relays get power. Im just stuck not a clue why it wont work.
Fleet Owner
Joined: Oct 2005
Posts: 20,786
Likes: 1,751
From: Kentucky
There is no dedicated injector relay. When the key is cycled from the Off to Run position the EEC relay (computer relay) is energized by the key. When you turn the key from Run to Start the computer energizes the fuel pump relay for 1 to 2 seconds. Then when it "sees" the pulses from the PIP (aka stator) inside the distributor it will re-energize the fuel pump relay and keep it energized until the PIP pulses stop and/or when you turn the key to the Off position. With no PIP pulses the fuel pump relay will not energize.
Does the Check Engine Light (CEL) illuminate when you turn the key to the Run position?
Does the fuel pump energize for 1 to 2 seconds when you cycle the key from the Off to Run position?
Does the Check Engine Light (CEL) illuminate when you turn the key to the Run position?
Does the fuel pump energize for 1 to 2 seconds when you cycle the key from the Off to Run position?
Thread
Thread Starter
Forum
Replies
Last Post
Matt Nalley
1987 - 1996 F150 & Larger F-Series Trucks
2
Feb 17, 2003 06:39 PM
BigDan
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
6
Jan 19, 2000 12:44 AM
