Hi:
I am new to the board. Just bought a clean, 108,000 mile 89 F150 with the 4.9. I am a first time F150 owner. I got the truck cheap due to a couple issues. The biggest issue I have seems to be surging at idle while in park combined with hard starting. I cleaned and tested the IAC which helped, but not much. I have no codes (11 11) with the KEKO test. With the run test I show a Code #42 (Rich Running). With the help of this board, I tried to check my Fuel Pressure Regulator but have no fuel pressure tester (yet). I removed the vac line on the regulator with the engine idling. The idle smoothed right out and fuel rushed out of the nipple on the regulator. I am thinking the diaphram on the regulator is broken and causing fuel to enter the vac lines and cause pressure issues? I'm not sure if I diagnosed this correctly, can anyone offer advice? I don't think fuel is supposed to run out of the regulator nipple when the vac line is unhooked? What is the easiest way to replace the regulator without removing the upper intake manifold?? Should I change the original O2 sensor since the truck has been running so rich? Thanks in advance!
A

 

yea you should have no fuel leaking out into the vacuum line. the 300 plenums arent too bad to take off. probably takes about 45 minutes tops using a flex head ratchet.i have 2 snap-on 100 tooth ratchets. id look but i dont have the truck with the 300 at the house. you might just be able to move it just enough to get at the regulator.

 

Anyone do this without removing the plenum?

 

I am going to attempt this today? Any tips to remove FPR without removing upper intake manifold? Thanks.