my 89 cherokee wont run for more than 5 min feul pressure at start up is 45 psi and once started drops to 7 psi then motor quits what is the problem and the cheapest easiest fix?

 

Could be the fuel pressure regulator, pull the vacuum hose off of while the engine is running and see if there is a rise in pressure.

 

does it do this when the tank is full

 

either FPR or fuel pump,both aint cheap,thats just my own opinion

 

i have already bought a fuel pump and fuel pump regulator and still have the same problem. would it have anything to do with the resistor on the front driverside fender that keeps shorting out and frying

 

i havent wanted to fill the tank all the way if i cant drive it but how would it effect the situation

 

That "ballast resistor" is only there to reduce noise on the fuel pump circuit. It's unlikely related, but to rule it out completely, you can safely bypass it with a piece of wire.

Did you have this problem BEFORE you replaced the fuel pump? What brand of fuel pump did you buy? Hope it wasn't an "Airtex"; that is a brand that I have had nothing but trouble with.

 

yes i did have the problem before changing fuel pump. i dont remeber what type but airtek doesnt sound familliar