Gas in Oil - Fuel Pump Failure?

[S4Cruiser]

S4, those are dark but they dont look like the coal black that I was getting when I was running too rich. And that would happen very quickly to new plugs, not sure if you said yours were new or not. If not, throw some new ones in and then go for a drive, it shouldnt take too long to turn them jet black (if it is running too rich). IMO those plugs dont look like it is running so rich as to be your strong gas smell problem but they do need to replaced.

Thanks for the help - I installed new NGK BPR5EY-11 plugs this morning (properly gapped them too), took the truck out for a spin (in town and highway driving probably <10 miles), pulled plug #1 and here's what I found.

Looks like I am running rich. Now where to start??? I did get my FSM in the mail today so that should help me with adjusting the carb. Can the carb be leaned out to fix running this rich or is a rebuild in order ?

 

[bucfan]

S4, yep with less than 10 miles on new plugs it looks like you are running a little rich, the third pic really shows it. Dont have any experience with the OEM carb, mine has a weber 38 on it. But x2 what flash02 says, make a small adj, clean your current plugs with a wire brush and take it for a drive. You already know you dont have to go far to see the rich condition. If this doesnt have any effect on the plugs also look at your timing, is it on? Weak spark will also cause the same look too. Maybe someone will chime in with the OEM experience. Good luck with it, let us know how it works out.

 

[flash02]

If I were you I would play with the mixture. Clean your plugs and turn you mixture adjustment screw in a bit, you want to make small adjustments then recheck your plugs. Your mixture adjustment screw is located at the base of you Carburetor on the valve cover side. Timing should also be checked once you have your carburetor adjusted. Keep in mind depending on how far you end up adjusting your mixture you may have to in turn adjust your idle. If you send Jim C a PM I'm sure he could give you a base line adjustment to start with. If you notice Black smoke from your tail pip, weather at idle or with acceleration and Dry Black deposits on your plugs you air fuel ratio is set up to Rich (too much fuel not enough air).

Good Luck!

Corey

 

[S4Cruiser]

Thanks bucfan!

I have no experience with carbs other than the one on my T-Maxx RC car, so this will definitely be a learning experience. I also have no experience with checking an engine's timing.

We all have to dive in head first at some point...time to start reading up on timing and carb tuning. Good thing I've got a lot of free time right no .

Anyone that has done the 60 series distributor and ignitor/coil conversion that could give me some pointers would me much appreciated (trouble shooting, etc).

-Jon

 

[S4Cruiser]

Another Update - Making Progress

I adjusted the idle mixture but that didn't seem to help so I figured I start with the simple stuff first to help remedy running rich...

I started a new thread --> https://forum.ih8mud.com/40-55-series-tech/266697-vacuum-line-routing-confirmation.html to help sort out my vacuum line routing. Thanks to Jim C's help I found out my routing wasn't anywhere near correct (Jim C is the man btw).

Fixed my vacuum routing, cleaned off the plugs and planned to take the truck for a 30 mile drive. Upon first startup I noticed the idle was considerably higher compared to before correcting my vacuum routing. I adjusted to what 'sounded' correct (don't have a tach) and went for a spin.

Fuel mileage seems much better now and I checked the plugs and was pleased with what I found (see pics). I might be running a little lean at idle so I'll reset the idle mixture screw back to where it was before.

Is it common/usual for incorrect vacuum routing/desmog to have such an impact on fuel mileage and running rich?

One issue that I'm still having is that fuel from the carb bowl drains empty overnight. I assume this could be either a stuck PV or a crack in the carb casting allowing fuel to drain into the manifold, down the cylinder walls and into the crank. I'm going to replace the PV and see if that fixes the problem, if not then buy a new/rebuilt Aisin carb...