F-150 Fuel Injector Seals

[Duke]

Can anyone please help me find a source for the seals that go between the gasoline injectors and the CNG injection ports? They are sqaure cut o-rings about 1 1/8" o.d. x 15/16 i.d. x 1/8" thick.

[Duke]

Re: F-150 Fuel Injector Seals

I found them at a Ford dealership with a CNG specialist. The Ford part number for the seals on my 2000 F150 bifuel is YL3Z-9F596-AB...the cost was 9.52 each. I also got the 2 smaller o-rings on the "pipe" shaped cng injector F85Z-9229-AB ($5.53 ea.) & F85Z-9F596-AB ($4.78 ea.).

[marty2611]

Re: F-150 Fuel Injector Seals

Did you replace these yourself? If so, is it difficult for a shade tree mechanic like myself? Thanks

[darress]

Re: F-150 Fuel Injector Seals

Marty,
This is supposed to be a pretty involved bit of maintenance but more time consuming than difficult. I have all the parts ready to go to do the o-rings, plugs, and coils at the same time. I'm just waiting for a bit warmer weather. Better to do it all at once than do it now and again down the road. Get the o-rings from Sno-Motion. They have Viton ones for about the same as the stock ones from the dealer.

[darress]

Re: F-150 Fuel Injector Seals

OK, the weather finally warmed up enough that I could spend some time in the driveway with the hood open. Let me say this, that was a very involved bit if maintenance. I would say that the most difficult part is just removing stuff that's hard to reach. The rear injector on the driver's side was a bugger. It's very slow going trying to fish tools in to reach various fasteners. I spent a lot of time cleaning the injector ports and the injector assemblies for re-install. They were VERY dirty. I was actually surprised at how dirty the CNG lines were. They had a rusty colored waxy appearing coating on the insides. The vehicle was from The East Coast so I don't know if the CNG had contaminants there or if that's just a common appearance after long term use. The truck has 129K miles and at 125k miles I had the dealer due an on vehicle flush/cleaning of the CNG system. I wonder if it was worse before the flush (the compuvalve has a re-manufactured sticker and did look clean on the inside though). On reassembly it took a bit if work getting all the injector ports lined up with the gas and CNG fuel rails and getting the o-rings seated. I accidentally cut an o-ring and had to make a run for another one (difficult to find by the way, thanks Jared/SNO-Motion). The truck idled quite rough on CNG before the coils/o-rings/plugs (but ran fine on gasoline) and now it is smooth on both fuels. There's a very common problem with Ford engines in this family blowing spark plugs out. Do a Google search, you will be shocked that no recall exists. A recall on this magnitude would put Ford out of business. For some reason plug #3 is a big culprit, and mine was on the verge of this happening. The #3 plug was very loose and I removed it just by turning the extension with my fingers. The coil boot was discolored by the leaking gases being pushed out into the plug pocket. I believe all the components I replaced were factory original so they did last a very long service life. I'm just glad I caught it before it blew out. I have several pics of the process if anyone has any questions. My truck is a 2001 F150 7700 series and has plastic CNG "pipes" on the injectors (plugs into the aluminum CNG fuel rail). Look to see if yours are plastic or brass before getting o-rings because they use some that are different sizes. The ones from SNO-Motion are made from Viton, which is a nice upgrade over stock ones. The dealer wanted about $1500 for this service.

[rothstar]

Re: F-150 Fuel Injector Seals

A very involved bit of maintenance indeed!

I had the misfortune of having the #3 spark plug blow out on mine. After replacing the threads with the Time-Sert Ford Triton #5553 kit, I decided to replace all of the o-rings and seals (also thanks to Jared from SnoMotion). Like Darress, mine were dirty and I spent most of my time wiping everything clean--sure looks nice under the hood now. I also made several custom modifications to seal the coil boots so that no water can get down into the spark plug wells (I have heard that water from the heater hose above plug #3 may contribute to its frequent ejection).

Samuel
2001 F-150
5.4L ExCab

[darress]

Re: F-150 Fuel Injector Seals

Hello Samuel. I've been really puzzled by the frequency of the #3 plug blowing out. I've been to many web sites with complaints from people about the Triton family of engines blowing plugs and the #3 is so prevalent that it can't be just a fluke thing. I didn't see any heater hose issue that could have caused water into the plug well on mine. Did yours appear to have a heater hose issue? All of the plug wells were amazingly clean on mine considering the grime above them. I should have maybe put a coat of sealant around the seat of the boots but I just got the seat clean and inserted it. The COP's seem to have a positive pressure to create a boot seal when bolted down. I am worried about future problems due to the spark plug hole design and low torque value/minimal threads to keep the plug in. I think that the plug loosens (for whatever reason) and the constant in-and-out action of the cylinder pressure just hammers the aluminum threads out of the head. I'll be paying extremely close attention to anything that sounds like an exhaust leak or tapping and locate/correct it quickly. The posts I have read have documented this in any/all of the cylinders. Keep us posted on how your thread repair fairs over time.

[CNGfamily]

Re: F-150 Fuel Injector Seals

You guys are probably all over this and when doing the repair at home it's not likely an issue... aluminum heads with insufficient threads + steel spark plugs = major problems removing plugs if the plugs are still warm. the aluminum cools quicker and "shrinks" onto the plug and you can damage the threads when removing them. That doesn't explain plugs that are loose already, just damage that could have contributed due to a previous tune up.