Engine power problems

[granchosen]

I have a 1994 v6 4.0 4x4 and it runs fine when cold cant red line motor.... when used or run for 15 mins it dont have any power and stalls out done a full tune up twice and now lost right now.

 

[MrShorty]

1st thing I'd probably do would be to put a fuel pressure gauge on it and see what fuel delivery is doing when it won't run right.

 

[granchosen]

i need fix my cat converter. and i got fuel problems. what chould cause losss of presure with gas. my fuel pump is good. what else will cause it

 

[MrShorty]

Main reasons for low fuel pressure:

1) pump not running due to bad pump or faulty wiring/relay/fuse.
2) clogged filter
3) regulator failed open

 

[glfredrick]

I'd also check the lower intake manifold bolt torque. I just pulled a manifold off of a 93 model at pull-a-part over the weekend and the lower bolts were just finger tight. I think the bolt torque -- though a known problem -- is under-reported as a cause to drivability issues in the Explorer and Ranger.

Try re-torquing to factory specs using the factory tightening pattern and see if it makes a difference.

(#1 - left rear, #2 - right front, #3 - right rear, #4 - left front, #5 - right center rear, #6 - left center rear, #7 - right center front, #8 - left center front) Torque to 14-21 foot pounds.

 

[granchosen]

it was a fuel pumponly pushing 20 pounds

 

[TedJ]

Trying to redline a cold engine under no load is a good way to blow it up.....

 

[granchosen]

i always red line the motor sence we had car sence 94

 

[92exp4x4]

i always red line the motor sence we had car sence 94

Why? And under what circumstances? Just curious, not attacking tradition

 

[jd4242]

Could be why it has no power.