Only Two of the injectors run constantly. The other two are staged to "Turn On" After certain RPM and Load requirements are met.
injector seat rings are shot or pluged you need to replace the injectors but replace all not just the two because you will have it apart anyway
there's four injectors you have two primary and two secondary , the primary injectors are on the top of engine very visible but the secondary you would have to remove upper intake plenum to get to them ...
1324
The firing order for the 2.5L engine is: 1-3-4-2
165432 is the firing order for the 4.3 L engine
1342
The firing order on the 2.5L 4 cylinder engine is: 1 3 4 2
the firing order 18436572 on the 1988 f150 302
1-3-4-2
1-2-3-4-5-6
Mine has fuel injectors
replace the o rings ,make sure you lube them You have filled the oil pan full of gas DO NOT RUN THE ENGINE
1-3-4-2