Help Needed skip on cylinder 8

[Tail_Gunner]

I will get some washers and shim the pressure regulator. If this corrects the problem, is this a band aid for future fuel system/injector problems?
Thanks

I think the Ford spec for fuel pressure was something like 40psi. But the International spec is higher for the same engine. The general consenus for a target value is 65 to 70 psi. Anything higher, is pointless and is harder on the fuel pump.

Another thing to consider is the "Hutch" mod to eliminate any air from getting sucked into the fuel between the tank and the pump.

 

[BIG JOE]

I will get some washers and shim the pressure regulator. If this corrects the problem, is this a band aid for future fuel system/injector problems?
Thanks

In my opinion ? It's not a Band-Aid.. Bumping up the fuel pressure to 65/70 psi, and eliminating sources of air intrusion in to the fuel delivery system are two of the Best Mods we can do.. It's a permanent FIX... for several fuel system (design) related.. performance Gremlins.

Joe

 

[Potentialbuyer]

If this fixes my problem, why did it wait until 168,000 miles to start acting up? Is there just enough junk in the fuel system so that #8 can't handle it any more with Ford's recommended fuel pressure of 50 psi? I did notice today that it does not skip when it is stone cold. After the engine warms up and leans out some, that is when you notice the skip. It is hardly noticable when idling either.

 

[Potentialbuyer]

I broke my ankle on Monday so I have some time to think about the skip in my engine before I can actually do anything about it. I added some Stanadyne (sp?) fuel treatment that has not changed anything after one tank of fuel. I have not been able to shim my fuel pressure regulator yet and I will do that next. If that does not change anything, I was planning to redo the cylinder contribution test to make sure #8 is my weak cylinder and check compression on that side to rule out a base engine problem. If compression is OK, I was going to replace #8 injector. I don't drive the truck all that much so waiting for fuel additives to make an improvement will take forever.
My question to you guys is what else I should do while I am in there. I have heard about intermittent connections with the valve cover gasket so should I replace the gasket? Should I replace the other injector o-rings and copper gaskets on the other three injectors on the driver's side when I have the #8 injector out or is it best to leave sleeping dogs lie?
Another interesting issue that has cropped up along with the engine skip is a small oil leak. It may leave a spot about the size of a quarter under the engine after the truck has been driven for an extended period of time. It is coming out from the drain hole in the flywheel cover but it is not the rear main seal. I looked in the valley of the engine and there is a puddle in the middle of the valley but I can't see where it is coming from. I found a bunch of bulletins concerning oil leaks in the valley area from the turbo pedistal and the HPOP. Both of these items don't have any oil dripping off of them that I can see. I used a good light and a mirror but I still didn't see anything. The 7.3 does not have a PCV but could my oil leak be coming from the ventilation system? Are there screens or filters that may be plugged? After 5000 miles, the oil might be 3/8" from the full mark on the dipstick (I have never had to add a quart of oil) so I don't think I have a blow by problem. There is never any smoke from the exhaust either. Thanks in advance for your help. Gil

 

[bigrigr]

Corrct me if i'm wrong, but I believe what BigJoe is referring to by saying a
"hot" mix, is that he reccomends mixing a stronger ratio of diesel kleen in your fuel(ie more additive to less fuel) I've used regular Atf in my fuel for years also, and it does seem to work to clean the injectors. Maybe try a quart to one fill up? Hopefuly a dirty injector is the only problem, # 8 gets all the fuel leftovers after every other injector, as it's last in line. good luck!

 

[JRJ04]

I would highly recommend that you not use ATF in your fuel...theres way too many detergents and other additives in it that are not good for your injectors...

I believe others will chime in here and probably tell you the same...

 

[Potentialbuyer]

I wasn't sure what a "hot mix" was but I added 50% more additive on the last tank of fuel. The normal ratio is 12 oz to 30 gal and I added 18 oz to 30 gal. Since I can't push the clutch pedal on my car (broken ankle), I will be driving my truck (automatic) and maybe the additive can do its job. Any thoughts on the oil leak? Gil