Fuel in oil?

[John-T-53]

Back up and running again now for a couple months. I have 900 miles on the oil since I put in new rings and rod bearings after the rod bearing failure this spring.

I seem to be running very rich, and it's getting progressively worse. Last night I was sitting at a traffic light for 2 minutes and the smell got to me and irritated my eyes pretty bad.

The engine runs very good at all speeds, but mpg is around 10. Timing is 8 deg BTDC with dwell set to 40 degrees. The coil produces about a 1/2" spark, and the plugs are new and gapped properly. The carb is good with float adjusted a little lower than spec and no vacuum ports are clogged. I have a PCV valve.

The oil has a few bubbles in it on the dipstick, but is clean looking, not too dark. I have a lot of soot out the tail pipe and grey/white smoke with acceleration. The smell is unbearably rich and I've been getting bad looks from people on the road.

The last thing I haven't checked is the mech. fuel pump. Are these prone to sending fuel into the crankcase?

[TodFitch]

A bad fuel pump diaphragm can leak fuel into the crankcase. And an older pump probably has a diaphragm that is made of materials that are not resistant to the additives in modern fuel.

[grey beard]

John,

What you describve may be blow-by smell. This is verry strong - almost nausewating in nature, apart from a normally rich exhaust smell. You are the guy who can smell this, and not us long-distance smellers. Give the crankcase vent tube a sniff and see if it's comong from there. I have a PCV system on my own Pilothouse, so I never smellthis. Rich running can come only from carb related problems. post back and let us know what you find.

[Don Coatney]

Why are you running 8 degrees advance on your timing?

[John-T-53]

Why are you running 8 degrees advance on your timing?

The thought was to advance as much as possible to lean it out a bit. Doing a search revealed others on here have it set around that too, plus or minus.

However, the shop manual says TDC...I think that is for static timing. (?)

Is 8 degrees too much? There's no pinging at all with this much or even at 10 or 12. It was set at 500-600 rpm with timing light and vac advance connected.

I have PCV, so in theory blowby should be sucked back in, but rings are new and fit good. It could be sucking in fuel vapor leaked from fuel pump making the mixure extra rich below the carb.

Edited July 21, 2010 by John-T-53

[Merle Coggins]

I would believe that if you had a leaky fuel pump diaghram, that put gas into your oil, it wouldn't be pumping very well and your truck wouldn't run at all, let alone run rich. The PCV system is a built in vaccume leak which will effect your fuel mixture. Have you tried to adjust the idle mixture screw? These vehicles will tend to run richer and stink more than a modern vehicle with catalytic converters and computer controlled fuel management. I've had complaints from my truck too if someone is in the vacinity of it idling. To me it just smells like an old vehicle running.

Merle

[John-T-53]

I pulled the fuel pump tonight, and inspected the area where the arm protrudes. I didn't notice a strong fuel smell at first (mainly because I had gas all over my hands from disconnecting the lines). I put the pump in a vise to hold it level, and after wiping away excess oil, noticed a small flow of fuel come down from the interior. There were about 4 drips within 10 minutes, and it was a clear liquid that smelled like gas.

I have a new pump on the way from NAPA.

This brings to light a lot of s**t....I might have just solved the other mystery why my rod bearings failed previously.

[Don Coatney]

The thought was to advance as much as possible to lean it out a bit. Doing a search revealed others on here have it set around that too, plus or minus.

However, the shop manual says TDC...I think that is for static timing. (?)

Is 8 degrees too much? There's no pinging at all with this much or even at 10 or 12. It was set at 500-600 rpm with timing light and vac advance connected.

I have PCV, so in theory blowby should be sucked back in, but rings are new and fit good. It could be sucking in fuel vapor leaked from fuel pump making the mixure extra rich below the carb.

In my opinion 8 degrees is too much. I am surprised it will idle that low with 8 degrees advance.

[MBF]

I'd venture a guess here that the overly rich condition is what is preventing pinging w 8 degrees initial timing. It's interesting that you have such a situation with the lean condition that can be created by the addition of a PCV system (depending on where the PCV vacuum source is). Are you running the PCV line to a vacuum port on the intake or to the air cleaner? If you have excessive blowby could that be creating the rich mixture situation? Just thinking out loud- Mike

[John-T-53]

I'd venture a guess here that the overly rich condition is what is preventing pinging w 8 degrees initial timing. It's interesting that you have such a situation with the lean condition that can be created by the addition of a PCV system (depending on where the PCV vacuum source is). Are you running the PCV line to a vacuum port on the intake or to the air cleaner? If you have excessive blowby could that be creating the rich mixture situation? Just thinking out loud- Mike

The PCV runs to the pipe plug location on the manifold, from the draft tube location. The oil filler tube is open via the breather cap - I did not plug it or run a separate line to the air cleaner.

There should be no blow-by in theory since the rings are new and the cylinders are freshly bored. In this case the fuel entering via the pump boss is creating the same condition, though.

After I install a new pump and change the oil, I'll see how it runs and readjust the timing.

Don - what's your preference for advance?

[Don Coatney]

Don - what's your preference for advance?

Book says zero. I am running about 2 degrees. I found that at 5 degrees advance my engine would ping when climbing steep hills.

[John-T-53]

Here's some pics of the old and new fuel pump.

I opened up the old one that was leaking, and didn't notice any holes in the diaphram, just a bunch of little cracks all around the circumference. I'd guess a few of these that went all the way through would provide a route for the fuel....in addition it could be leaking through the center stud. Anyways, without a doubt this one is done.

I'd like to rebuild it and keep as a spare. Anybody been successful in finding kits for these?

[TodFitch]

Antique Auto Parts Cellar also doing business as Then 'n Now manufactures kits for rebuilding fuel pumps.

[John-T-53]

Antique Auto Parts Cellar also doing business as Then 'n Now manufactures kits for rebuilding fuel pumps.

Thanks Tod, I will check them out. Rebuilding fuel pumps and other engine accessories are always fun little projects. I like getting into the details...

To finish this one off, I installed the new pump and changed the oil, then took the ol' gal out for another maiden voyage down the 101 tonight. There was no more smoke, and the exhaust smelled good...I mean, more like a healthy engine on an older vehicle. No more fumes in the cab either. I think it'll take some 'no holds barred' driving on the highway to blow all the soot out of the engine, though.

Now I can finally get to the next project....the T-5.

[41/53dodges]

good deal!

good to hear about your truck being back on the road, and let this be a good message for everybody about un-rebuilt fuel pumps. be kinda crappy for something like this to happen to somebody else.

[HanksB3B]

ate the new bearings in the first place on your way up to your new job. Oil thinned out with gas is probably close to having no oil at all. Now I'm all nervous (my oil "feels-fine" though). If you find a kit please let me know where and how much.

Glad you're back in the running,

Hank

Edited July 30, 2010 by HanksB3B

[Merle Coggins]

I have rebuilt a couple of pumps with kits from Antique Auto Parts Cellar. They are great folks and willing to help you determine what pump you have if you can't find any numbers. Otherwise just clean it up good and find the make and model number which are usually cast or stamped into the body somewhere. Then give 'em a call. They'll tell you which kit you need and you can order it up. I think I paid around $45 for the last one, including shipping. The last pump I rebuilt I couldn't find the numbers on the pump but it had a tag on one of the bolts. I took pictures of the pump and tag and emailed them. They were able to identify it and tell me which kit I needed. I then called and ordered the kit. They're fairly easy to rebuild. If you have an old one laying around I recommend getting a kit and rebuilding it. Then keep it in a small box under the seat of your truck. If your current pump fails on the road you'll have a spare on hand. (It happened to me and I had my rebuilt pump under the seat).

Then and Now Automotive / Antique Auto Parts Cellar

781-335-8060 or 781-335-1579

http://www.maritimedragracing.com/then_and_now_automotive.htm

Merle