1990 F-150, not enough gas on one bank of cylinders on 302
 

Just bought this 1990 F-150, 302FI, AOD trans. Motor has been rebuilt and is really strong.

New Hi-Po cat and turbo muffler

Installed new plugs, wires, rotor button and cap, air filter.

Had it hooked to a scanner and it shows that one side is not getting enough fuel.

Don't want to pay a dealer $75.00 per hour to stare at it so I'm hoping someone here can give me a list of things I should start looking for.

I'd appreicate any ideas.

I can do most of the replacement work.

Thanks

Joe

Would you like to share the code you see? Is it code 41/91 or some other code?
Reason I ask is there is only one OX sensor on this truck.
How is it being determinrd that the right bank is lean?

Got your message Joe.
I would first clean the throttle body and the IAC controller.
These are the first units right at the air input from the large air inlet hoses.
Get throttle body cleaner in a spray can for that purpose. Hold the throttle open and spray all around in the bore to clean all accumulation.
Remove the IAC from the throttle body and clean it's inside.
If you still have any rough idle left, the EGR valve has to be tested for hanging open and letting exhaust gas into the intake.
This system consists of three items. The EVR and the EGR and EVP.
The EVR has a filter in it's cap that can plug with dirt. This EVR gates vacuum to the EGR to open it then lets air back in to allow it to release. If either action is faulty you have a problem. The EGR can be tested with a vacuum hand pump or temp engine vacuum supply.
To find the EVR follow the small hose back from the EGR to it.
Opening the EGR on an idling engine will cause rough idle proving it is not hanging open and does work with vacumm application. If the valve opens and no rough idle is apparent then the tube to the exhaust is plugged or rusted open to air.
The EGR system only operates during cruise and mostly in OD between about 1800 and 2400 rpm and at no other time.
A bank only problem could be the injector plug ups from the computer.
This engine has what is known as batch fire injector operation. This means that 4 injectors are operated at the same time in groups of 4 and never changes.
Go with this and see what the results are.
Good luck.