1990 IDI pressure sensor on injector

[mikadobrain]

Hello,
I'm currently replacing the injectors on my 1990 7.3 L IDI engine. Had lots of struggle to get the injectors out, but after a few weeks of patience and lots of different techniques tried i finally managed to change 7 if 8 injectors.
The last one is #4, drivers side, second from the front of the car. There is a strange fitting between injection line and injector. I learned from research that this is a pressure sensor, that is not connected but needed for correct timing, because it ensures that the distance between pump an injector is the same on all lines.
What puzzled me is the fact that internet told me this sensor would sit on #1 on truck IDIs, but mine is sitting on #4. I now suspect the previous owner may have switched it to the wrong injector without knowing - causing one slightly longer (#4) and one slightly shorter line (#4).
Would one notice the difference by ear? Would that do any damage to the engine?

Can anyone confirm that it normally sits on#1?


Apart from that the flare nut of this line is seized to the line. Line turns whenever i try too loosen it. I fear breaking the line. Are there any tricks i should know of?
And are there cheaper options for sensor replacement than the more than 200$ parts i found at rockauto, in case i break it? I dont want a sensor, a "dead" piece to lenghten the line in question would suffice... I cant handle paying that much for a simple adapter.


Your collective wisdom is greatly appreciated

Thanks,
Michael

[rossvtaylor]

Since we have a 1990 E-350 with a 7.3 IDI sitting out front right now, I just went out and pulled off the doghouse and looked at it. Our sensor/extension/widget thingy is also second back from the front, on the driver's side. I can't help with the removal question, as I am not at that stage yet, but here's a photo of ours...taken from the back, towards the front, on the driver's side.

[Booyah45828]

That's an adapter used to time the engines at the factory. It will be on either cylinder 1 or 4, depending on whichever is easiest accessed. In trucks, it's #1. Vans have it on #4. IH put it on #4 as well.

You can swap to a #4 truck line, and eliminate that adapter altogether. The guys in the pickup world will eliminate that adapter and replace their #1 line with an adapter less one out of a van.

You'll need something there, though, because the line likely won't bend enough for you to replace it without it. And in a diesel, the injector line length is important to keep the injection timing correct cylinder to cylinder. If you do manage to get the line bent enough to attach without the adapter, the engine will still run, just that cylinder will be firing earlier then the rest.

If you can't get it apart, replace it with another. Guys part these trucks out all the time, so you should be able to buy a whole set of used lines cheaper then a new adapter. Also, don't forget to reinstall the line holding clamps, or the vibrations will crack the lines over time.

[mikadobrain]

Cool, thank you guys. So i will give it a try and just replace it with a #4 truck if i break it.

Just curious: how does that factory timing work? What exactly do they use the adapter for?

Michael

[Booyah45828]

The adapter is used for a timing meter that clamps on it. Those systems are nearly obsolete though and the meters that are available don't utilize the adapter.

[s2mikon]

Try putting heat on the line nut not the line. I have had to use a propane torch in the past. Just be careful and not burn the thing down. Have a fire extinguisher handy. And the advise about the line clamps heed it.

[mikadobrain]

A Torch with some WD40 did the trick, thanks. Line is removed and everything in good shape.
Now working on getting out that injector. It's stuck, as were the other 7. Will just be a matter of time until it comes out.

I think i will make a necklace out of that ground-down injector tops