Mechanical fuel pump

[Trueoo7]

Was having some problems with fuel (in the oil) was advised to replace the fuel pump. When I went to reinstall new pump, the directions said to make sure that the cam lobe that it rides on is in the lowest position. Got out my mirror and turned over the engine and noticed that the lobe not only turned but also wiggled so I stuck a dowel in there and I can move this so called lobe up and down and even sideways. Maybe a 1/8" to a 1/4". The only way I can describe it is, it seems like a tire that is sitting on a rim loosely and the tire is not seated to the rim so you can move it around a bit, like its flopping around. Is this the way its supposed to be?
Pulled off the valve covers and everything seems to be opening and closing properly. I don't have a fuel pressure gauge so I don't know what pressure it was putting out prior to this.
Thanks
Trueoo7

[TerribleTed13]

Trueoo7,
No that lobe should not have any play! That is the fuel pump eccentric and is held to the camshaft with 1 bolt. Its more like a pulley that has a small tab that extends to keep it in place. You need to pull the timing cover off, and use red locktight on that bolt to make sure it dosen't come loose. The rest of the valve train will be fine, as your inspection showed. The instructions indicate to have the lobe on the low point, so your not fighting the fuelpump arm spring during installation. Just "bump" the engine around so the fuelpump slips into position. But you may want some pointers on the removal and installation of the timing cover.

[Rick Parker]

Many times with the timing chain sets there are 2 different length drive pins included one of which is to be installed in the cam prior to the gear being installed. The longer one (for this purpose, mechanical pump ) protudes through the gear and then the fuel pump eccentric registers on it and is secured with a bolt through the center. If the short dowel was used OR if the center bolt has become loose the eccentric will not be able to drive the pump arm. Use RED (242) locktite on the center bolt. Inspect the pin fit in the cam too. You have actually dodged a bullet.

Rick

[Bruce Edwards]

Hold ON!!!!!! If you have the LATE style fuel pump eccentric it is in two parts and the outer ring will move a bit on the innner. That is NORMAL as it acts as a bearing surface.
Just for the record unless the fuel pump has a bad seal on the engine side it CANNOT put fuel into the engine oil.
Most fuel in the oil can be traced back to overly rich fuel mix or a choke not set correctly. That of course will cause the same thing. Really hard on the cylinders and rings.

[Trueoo7]

Bruce
Right you are my good man. Went to an engine builder and that is exactly what he told me. I was sweating that one as the engine would have had to be lifted up to get to the harmonic balancer since the frame was in the way. Thank you for comfirming that, I will sleep a little better tonight. I think I have it narrowed down to the carb. Its a Demon and I've found some things wrong with it like the back bowl is bone dry, blew through the tube and it shuts off and on. Bowl floats in gas so that not the problem. Did the same test with the front bowl with the same results. Biggest thing I found was a tiny piece of the body cracked off where the choke pivot arm passes through the rim that the air cleaner sits on. Its on the underside of this rim and it holds a brown plastic plate in place that the pivot arm passes through. Now the choke hangs up or should I say binds up pretty good. There must be more wrong too as I tried to run the car with the choke in the wide open position but it still won't run at all. I'm sending the carb back to Demon tomorrow to see what they can do.

Someday I'll get to drive this beast again, I hope !!!!

Trueoo7

[Bruce Edwards]

Glad I could help. I have seen alot of bad things about the Demon lately. Make sure you do nothave any vacumn leaks. The biggest thing I see is the wrong carb mounting gasket being used. Make sure it matches the carb base as well as the intake flange.