3.0 to 4.0 swap and need some help


crazypel

10+ Year Member

Joined
Mar 7, 2010
Messages
4
Points
3,001
Vehicle Year
1991
Transmission
Automatic
its been awhile since ive been on here. i have a 91 ranger with a 3.0 which blew up. i bought a 4.0 out of a 90 ranger and i got all of the electrical out of the engine compartment.now that the motor is installed,this is where i need some help and hopefully some answers. the motor turns over and will only start if i prime the throttle body,so what am i missing to get power to the fuel pump and also am i missing a section of wiring because i have no hook up for the alternator.any help or suggestions would be greatly appreciated because im kinda stumped on what to do,so can anybody help me figure thus out? thanks.
 
Click

Does relay "CLICK" when circuit is energised? If so follow wires to the cannon plug located on driver's side by frame make sure its pinned correctly match color code's. I "THINK" this relay "PASS SIDE FRONT FENDER" also opens the ignition and fuel injector circuit's which leads me to think pin misalignement 4 wire's 2 fuel pump .As 4 the alt if you grabbed ALL the ranger wiring connection's SHOULD be there. There's a thread on here on how to repin plug it's very thorough with good pic's GOOD LUCK!:icon_welder:
 
Last edited:
Well i got power to the fuel pump but i had to run a jumper wire,as for the alt.problem, i laid out the old 3.0 harness and the wires for the alt. come right out of the fuse box in the engine compartment where as the new 4.0 harness there are no wires like found in the 3.0 that come from the fuse box in the engine compartment.its slow going but eventually i will figure it out i hope and thanks for your input and help.
 
Welcome!

PEOPLE on here helped me so just try to help other's with what you learn.:icon_thumby:
 

Sponsored Ad

TRS Events & Gatherings

Featured Rangers

Want to see your truck here? Share your photos and details in the forum.

TRS Latest Video

Official TRS Merchandise

Follow TRS On Instagram


Product Suggestions

Back
Top