I have never worked on a van, but you have to pull the whole fuel rail assembly off to get the injectors out. If you can't do that with the manifold in place, it has to come off. I had to pull the intake plenum off on my v6 ranger, I would assume you are going to have to also.

I bought my injectors off ebay. Wherever you can get them the cheapest.

I just looked on Rockauto, those things are not cheap. Is there a good reason you need to change them? I took a set to the Ford dealer and they had a injector test machine, and they charged me like $40 to check some injectors awhile back. They can check spray pattern and flow, and make sure they turn off without leaking. They also put some powerful cleaner through them with the machine also. I took the injectors off myself, so all they had to do was plug them into the machine and check them.

 

 

Just curious, do you have symptoms of bad fuel injectors, or do you have extra cash and time on your handsand want to do some preventitive maintenance ?
Injectors can be cleaned and electrically tested.
FYI; Don't buy injectors that exceed the flow rate of the stock injectors or you will flood your engine.

 

I had a set of injectors cleaned and tested one time (about 15 years ago) at the place linked below:

https://www.cruzinperformance.com/fuelinj.html

He sends you a neat little before and after test results chart. Mind you they were for a Toyota 22RE engine, not a Ford.

There was nothing wrong with the injectors that I know of, but I was rebuilding the engine, and with everything else being new, I also wanted fresh injectors and injector seals, etc.

I wouldn't worry about them too much at 155,000 miles.

 

 

The OTC 3398 just actuates the injector. What fails on injectors is either the spray pattern or they just quit. If they quit that cylinder will be dead. To check the spray pattern they need to be pulled and bench tested then the OTC 3398 would be handy to trigger the injector.

But at 155K miles I would not bother replacing them unless you have a dead cylinder or the cylinder balance self test shows an issue.

 

Another issue I have found with injectors, is that the screens get filled up with small debris that comes in through faulty fuel filters......

 

 

He is just flow testing the injectors, you do need to do this with Ford's as the ECU tests for it in the cylinder balance test, this is a function GM or Chryslers system did not offer and this hence the need for the above test with the OTC tool.. The Ford OBD I has much more advanced system for load calculations and fuel delivery than the GM or Chrysler system did, the ECU can tell you that same info in the cylinder balance test, plus it still does not let you see the spray patterns, something the Ford OBD I system usually picks up in the cylinder balance test if one injectors spray pattern is wonky. Ford's Pre EEC V (OBD II) systems did not offer sensor data streams to scan tools and requires a breakout box between the ECU and engine harness to read the data streams to/from each sensor/injector. The break out box has advantages as it makes it way easier to find harness faults and ECU faults as well as allowing you to read the actual the data stream. Over all the Ford system was far more reliable than what GM or Chrysler was using but it was more sensitive to ground issues.

 

 

 

1986 5.0L is MFI.
2 banks of 4 cylinders, 4 injectors fire, then the other 4 injectors fire.


1,4,5,8 is tied to one bank and 2,3,6,7 are tied to the other bank.

 

Another failure mode of a injector is it will not seal off when it's off, and may dribble or drip. There are tests you can do for this while they are still on the engine. The first thing you do is hook up a fuel pressure gauge, and run the engine, and then turn the engine off. You then watch the pressure gauge with the engine off, it should maintain pressure for a long time. If the pressure drops, you know you have a leaking fuel regulator, faulty check valve in the fuel pump, or a leaky injector. There are another set of tests to narrow it down to which one it is.

The Ford injector testor at the shop test the flow rate also. But like was said, they must come out to do all the tests with the machine they have.