Heavy carbon on #7 injector.

[Darryl97420]

Recently I had a problem with an injector partially melting and covered with carbon. When I bought a new injector to install, it wouldn't fit into the injector. My solution was to see if the injector would fit into cylinder 5 which it did then I put the old injector from 5 into 7.

Its time for new injectors and an IP.

Now move forward to today. I pulled the injectors and most were in good shape considering they were installed in 89. But the one injector from #7 was covered in carbon. Before I throw another injector in there, should I do anything? What about putting in a larger washer or maybe a second one to help with sealing out the carbon?

The rebuilt injection pump should be here tomorrow and I would like to get everything in order before I install it.

Thanks,

Darryl

 

[flareside_thun]

Did you replace the fire washer when you replaced the #7 injector before? A bad fire washer seal is what causes the carbon to build up into the injector bore. Stacking 2 washers will only cause the problem again. Make sure you do your best to clean the injector bores with carb cleaner and a pipe cleaner. Any kind of leak will only cause future problems.

 

[Darryl97420]

Carb cleaner? How does that work, spray and scrub then blow it out by cranking the engine? I intent on stopping by the gun shop and grabbing some cleaning brushes to handle the scrubbing part and some SeaFoam spray for the carbon.

Once clean now do I make sure there is a good seal with the fire washers?

 

[flareside_thun]

Yup, that's how I do it...find the torque specs for the injectors(I think It's 35 ft/lbs) or just get her goodntight, but don't over-tighten.

 

['94IDITurbo7.3]

33-35 ft lbs on the injectors.

A small ice pic works great for getting the carbon out.

 

[icanfixall]

Sounds like you didn't replace the copper washer from the first injector replacement and maybe added a second one on top of the old damaged one. The ice pick will get the carbon moving. Once you remove the original copper washer drag the ice pick or a dental around the seat in the head. If it stops moving around the surface thats a cut from compression gas burning across the seat. You will need a seat cleaning tool to repair that.

 

[Darryl97420]

I do know that when I tried to put a new injector into #7, the injector would not seat however an old one did. But now that I am home I would like to make sure that I get a new injector in #7.

When I am done cleaning I will post a picture of the bore to see if there is anything I am missing.

 

[ford390gashog]

I use a vacuum to clean up the bore as I go I don't want the big pieces falling in the engine.

 

[Dsl_Dog_Treat]

Using forced air into the GP hole will keep the chunks to a minimum.
Also, but wear eye protection when doing it.

 

[Darryl97420]

Would you believe that the valve cover was over just enough to prevent the new injector from going in? Once I loosed the cover just a bit and bumped it with my palm the injector dropped in.

All injectors are in. Thank you everyone for your help.

How I need to find a thread on swapping out the IP and how to manage the fuel lines.

 

[flareside_thun]

I believe agnem has a write-up on that. may want to check out the technical articles section of this forum.