64 Cad Dumping Fuel into Oil!!!

[Bobby B]

I've been running the Made in USA Spectra Premium Fuel Pump in my 1964 Coupe DeVille since I rebuilt the engine in 2012 with excellent results. I also keep a few on hand and have sold a dozen or so to customers over the years with no issues reported.  Part # for the 63 & 64 Cadillacs is B1297MP.   I do agree things are becoming cheaper but if you dig around you can find some decent replacement parts. Here are pictures of the Spectra Premium pumps that look very similar to the originals I have pulled from many parts cars:

If I'm not mistaken, Spectra Premium makes all the in-tank electric fuel pumps for GM.
                                                                                                                      Bobby

[64\/54Cadillacking]

Sorry to bring back this thread from the dead, but gas is entering the oil yet again.

As you guys already know, the fuel pump is new, but when I started to feel the engine idle being a little more shaky than usual, I decided to check the oil, and sure enough there's was no oil registering on the dipstick. There was some, but you can tell it was spotty on the dipstick and smell of gas is strong.

Now, I am not sure if the problem is the new fuel pump, but before I go start replacing parts and wasting money, is there a way to check to see if the carburetor could be leaking a lot of gas into the intake? The carb was rebuilt last year, and these engines love to run rich, as a matter of fact, if I even try to lean out the carb just a little, the engine idles terribly.

I know that I tend to need to hold my foot on the gas slightly when the engine is cold in order to keep the engine from stalling out, but will this cause the problem?

[Scot Minesinger]

Did you replace the fuel pump with the Spectra unit recommended by Jason Edge?  If not did you replace it with a warranty fuel pump that provided the one that failed in the first place?  If you replaced the fuel pump with the parts store warranty product, then it probably is the fuel pump again.  There was probably a bad run of them in China.  They count on us driving our collector cars for 50 miles a year.  Unfortunately a terrible part of the hobby.  I have replaced parts two and three times every once and a while when I first started in the hobby.

If you did replace the fuel pump with the one Jason recommended, I got nothing and go ahead and stop reading here.  It is not the unburned gas gets past the rings and into the sump during warm up suggestion.

Buy the fuel pump Jason recommended.  He is quite accomplished on the 63 and 64 Cadillacs and I would trust the brand he recommends.  The downside risk of using a faulty fuel pump far outweighs the cost of a quality fuel pump.

If so much gas went into the cylinders while it was being warmed up that not all of it burned and leaked past the rings down into the oil sump it is unlikely that the car would run at all.  Accordingly, do not think that is it. 

Good luck on this and keep us posted.

[64\/54Cadillacking]

Thank you so much for the swift response Scott!

I replaced the pump under warranty, and it is made in the U.S. by Precision Fuel Pumps from O'Reilly, this is what I find disturbing. New USA parts being faulty right out of the box.

I will go ahead and get the Spectra brand pump, and do this all over again. I just wanted to make sure I didn't have to tear up my Carb in order to find out the cause.

[Scot Minesinger]

In 2012 I bought 3 rebuilt alternators by AC Delco that were probably rebuilt back in the 1980's and were good for most Cadillacs.  The time came to use one and it was DOA, same with the second one and so I took all three to my local electric shop and had them all rebuilt.  (loss of manufacturing in America from the 1970's and 1980's was due to high labor cost AND POOR QUALITY - exemplified by these three alternators ) Replaced the original water pump on my 1970 RWD Cadillac 500 miles ago and it bearings went bad, had to replace it again.  Point is one of the most frustrating part of the hobby is the quality of the replacement parts. 

It is probably not best to stop by a local parts store because they think everyone wants price and the quality is the very lowest.  I like Rock Auto because they offer choices of quality.  In consideration of the labor and trouble parts are to buy, ship, install and test, it is most economical in terms of not installing work twice and not breaking down to buy the best part you can.  I often use USA Parts, and I keep telling them to make sure it is quality, hope they are doing that. 

Hope this resolves the problem!

[Jeff Rosansky CLC #28373]

How fast did the fuel get into the oil- at least to where you noticed it?  50 miles? Just idling in the garage?
Jeff

[Dan LeBlanc]

Thank you so much for the swift response Scott!

I replaced the pump under warranty, and it is made in the U.S. by Precision Fuel Pumps from O'Reilly, this is what I find disturbing. New USA parts being faulty right out of the box.

I will go ahead and get the Spectra brand pump, and do this all over again. I just wanted to make sure I didn't have to tear up my Carb in order to find out the cause.

Did something change with the 429?  I know some high performance engines have to run rich to the extent that the exhaust makes your eyes sting but that is not the case with my 61 390. I can pull any spark plug and the fouling on them appears like any modern car I have.

How many turns out are you getting on your mixture screws. 2 1/2 turns out from bottomed out is the baseline. If you can't get that far out and need the car to run richer to maintain idle, you've got another problem besides the fuel dumping into the oil. The fact that you need to hold your foot on the gas to maintain a cold idle tells me there's a vacuum leak somewhere also.

Even after sitting for a prolonged period of weeks, I can start the 61 with 1 or 2 pumps and immediately be able to drive.

Have you checked vacuum,  timing, and compression on this engine?   How many inches of vacuum are you pulling?   What's is your timing set to?  What's the compression?

[russ austin]

I would suggest an electric fuel pump.  What carburetor are you running? If its the Rochester, is it leaking down the intake?

Does you car have the AC type factory fuel filter?  The proven electric fuel pump and safety switch setup I use is for a non return line system.

[64\/54Cadillacking]

How fast did the fuel get into the oil- at least to where you noticed it?  50 miles? Just idling in the garage?
Jeff

After few trips, but more so just recently. I added 2 gallons of VP Racing 110 Leaded octane gas the other day and drove it a good 20 miles, but I am not sure if the lead in the gas could cause harm to the fuel pump. I noticed the gas in the oil after checking the oil on the dipstick.

Did something change with the 429?  I know some high performance engines have to run rich to the extent that the exhaust makes your eyes sting but that is not the case with my 61 390. I can pull any spark plug and the fouling on them appears like any modern car I have.

How many turns out are you getting on your mixture screws. 2 1/2 turns out from bottomed out is the baseline. If you can't get that far out and need the car to run richer to maintain idle, you've got another problem besides the fuel dumping into the oil. The fact that you need to hold your foot on the gas to maintain a cold idle tells me there's a vacuum leak somewhere also.

Even after sitting for a prolonged period of weeks, I can start the 61 with 1 or 2 pumps and immediately be able to drive.

Have you checked vacuum,  timing, and compression on this engine?   How many inches of vacuum are you pulling?   What's is your timing set to?  What's the compression?

I am not sure what changed besides for the pistons, crankshaft and cam. The engine does put out more power than most other engines for it's time including the 390, and it's my guess they needed to run rich because of the increase in HP.

Compression is strong, each cylinder has 165 lbs (from what I recall) of compression, no drops of any kind. Timing is set at 5 degrees and vacuum is a little shaky on the gauge but reads about 18.

I actually have to turn the mixture screws on the Carter carb almost all the way out, a good 5 or 6 full turns just to get the engine to idle somewhat smooth. There's no smoke from the exhaust, so that is a good sign.

Other than the gas in the oil, the engine runs great.

I would suggest an electric fuel pump.  What carburetor are you running? If its the Rochester, is it leaking down the intake?

Does you car have the AC type factory fuel filter?  The proven electric fuel pump and safety switch setup I use is for a non return line system.

Yes it has the factory fuel filter, I was thinking about this, if I keep having trouble with these mechanical fuel pumps, then I am definitely going to go this route.

[64\/54Cadillacking]

In 2012 I bought 3 rebuilt alternators by AC Delco that were probably rebuilt back in the 1980's and were good for most Cadillacs.  The time came to use one and it was DOA, same with the second one and so I took all three to my local electric shop and had them all rebuilt.  (loss of manufacturing in America from the 1970's and 1980's was due to high labor cost AND POOR QUALITY - exemplified by these three alternators ) Replaced the original water pump on my 1970 RWD Cadillac 500 miles ago and it bearings went bad, had to replace it again.  Point is one of the most frustrating part of the hobby is the quality of the replacement parts. 

It is probably not best to stop by a local parts store because they think everyone wants price and the quality is the very lowest.  I like Rock Auto because they offer choices of quality.  In consideration of the labor and trouble parts are to buy, ship, install and test, it is most economical in terms of not installing work twice and not breaking down to buy the best part you can.  I often use USA Parts, and I keep telling them to make sure it is quality, hope they are doing that. 

Hope this resolves the problem!

Well I just ordered the Spectra pump today, so I'll keep everyone posted on how the repair turns out. The very old stock new parts was better made, but you're right even US made parts can be bad. IT all depends on who makes it, and the  materials that were used.

[Stinson]

Here is the information:    http://www.classiccadillacwaterpumpsforsale.com/

The owner's name is Carl.  I stumbled into his shop when my brother purchased a Sebring convertible from him.  He has a nice clean shop with dozens of boxes coming in and going out every day, and I had him redo my 1960 water pump and fuel pump.

Fair prices and a quick turnaround.

Contact him and he may have a vintage core to start from and he makes his own diaphragms from modern material that resists the damage that ethanol creates.

Good luck.

Brian

PS... Let him know that you got his name from the Cadillac Club so he knows we are supporting him.

I can tell you from experience that Carl will go out of his way to help solve problems and recommend the very best options to create/repair your parts. He built and installed a new bearing for my '37 fan and he built and installed a modern bearing within my water pump - now no leaks and no vibration. I'm now sending him my fuel pump, generator and starter following certain tests he recommends to determine what needs to be done. I can't believe I found someone who knows his trade so well and is so honest - wish I could say the same for the man who "restored" all these items during my car's recent restoration.
Ty Stinson 

[Scot Minesinger]

Your post reads like there may be a vacuum leak, as that is what a fluttering gauge usually indicates.  It does not seem like a vacuum leak would cause fuel in oil, or half the people I know what suffer same problem.  You should find the leak, just remember any original (or of unknown history) vacuum hose that may look good is not and should be replaced.  Check around base of carb too.

Not familiar with what the carb adjustment screws on a 429 mean in terms of number of turns in and out, as my work is all with Quadra-jets on 472/500 blocks, however they do not seem to correlate from one Cadillac to the other.  Meaning one car may run perfect with 2 turns out another perfect at 3.5 turns out.  I use a vacuum gauge and ear to set mine.

[russ austin]

The Carter carb is not going to drip fuel into the intake while sitting, unless there is a crack somewhere at the base.

6 turns out at the idle mixture screws is way too much. Initial settings is 1 1/2 out. I have mine very close to that setting.   Have you played with the large central screw between the idle mixture screws?  Its the idle, and one affects the other.

[Scot Minesinger]

Forgot to ask is this an a/c car with a return line back to tank. If not that is always a good idea to prevent vapor lock and keep the fuel pressure from building between pump and carb, which may put pressure enough at pump to leak into oil.

I do not like an electric fuel pump at all.  If you go electric you need to make it so your daughter can drive the car without special operation instructions.  By daughter I mean a person unfamiliar with your car, as sometimes this happens.  The pump only operates in run position, there is some means to relieve fuel pressure and send it back to tank (mechanical fuel pump varied with rpm, electric is constant) such as fuel return line, the pump must stop if the engine is not running but the ignition is on (daughters do this to listen to radio, not aware of accessory position), and etc.  The good thing about the electric fuel pump is this fuel mixing with oil via fuel pump issue would go away.

[Jeff Rosansky CLC #28373]

20 miles is awfully fast.
When you pull the fuel pump, look at the plunger arm.  It it nice and clean?  If so then I would think fuel is indeed leaking past the diaphragm and washing the oil off the plunger arm.
Can also pull the carb (when full of fuel), lift it half an inch and slide a piece of cardboard under it and then just let it sit on the manifold as normal.  After a while, pull the cardboard and see if there is any fuel staining on it which would indicate fuel leaking out the bottom.
Jeff

[Scot Minesinger]

That is a good idea Jeff has about cardboard under carb.

[64\/54Cadillacking]

20 miles is awfully fast.
When you pull the fuel pump, look at the plunger arm.  It it nice and clean?  If so then I would think fuel is indeed leaking past the diaphragm and washing the oil off the plunger arm.
Can also pull the carb (when full of fuel), lift it half an inch and slide a piece of cardboard under it and then just let it sit on the manifold as normal.  After a while, pull the cardboard and see if there is any fuel staining on it which would indicate fuel leaking out the bottom.
Jeff

That is a clever idea! I'll try it out. I just want to get to the bottom of this problem.

Scott, my car does have A/C and has the return line on the fuel filter.

As for the carb mixture screws, why does it take so many turns in order for the engine to run smooth? I knew when I went to adjust the mixture screws, a good 2 1/2 turns out should've done the job, but at 5 or 6 turns out something isn't quite right.

I did adjust the curb idle screw because on a cold start, the engine would rev insanely high with the choke closed, so I turned the screw in 2 full turns to lower the idle and this helped keep the engine rpms in a more sane level at start up. I might need to tinker with the carb again. The big center idle air screw just increases the rpms, and doesn't affect actual idle quality. In the shop manual it even states to keep the air idle screw at the lowest levels as possible, while getting the idle mixture screws in balance to increase the idle rpm while still maintaining a smooth idle.

While we are talking about the carb, can anyone help me figure out how to get transmission from jerking harshly from P to D to R. I know when I adjust the throttle rod on the carb to lower the idle/pedal level. it helps, but then the idle is too low. Instead of a smooth soft transition from P to R to D, the trans jerks hard where it almost feels like something might break. Other than that the transmission shifts very smooth with no noise. BTW the vacuum modulator is new and I still have this problem before I replaced it.

[Dan LeBlanc]

Sounds like you're going about your adjustments all wrong.

There should be a screw on the linkage on the side of the carburetor for the fast idle cam to set your fast idle speed.

You should not be using the throttle rod to make any idle adjustments.  If anything do this with the linkage disconnected to ensure the throttle plates are fully closed and then adjust the rod so that it enters the carburetor linkage with the throttle plates fully closed and the choke open.

All idle adjustments should be done with a vacuum gauge, tachometer, and the three screws on the front of the carburetor.

[76eldo]

If the carb was making the car run so rich that gas was washing past the rings and filling the crankcase with fuel the car would have to also be fouling plugs, flooding out, and the exhaust would be extremely rich and disgusting.

The fuel pump is the only place where there is a potential for fuel to get into the oil.

As I suggested, if you get an original fuel pump rebuilt properly and try that, you can rule out the fuel pump.

If the diaphragm is torn or defective an electric pump installed temporarily with the fuel pump connections bypassed entirely will prove that it's not the carb.

Brian

[64\/54Cadillacking]

I'm going to have to do a carb adjustment after I install the fuel pump and double check for leaks all around. As frustrating as it is, I find this challenge fun and take it as a learning experience.. Thank god these cars are easy to work on as well. 

I'm also getting tired of replacing the oil over and over again. It's just another unneeded added expense

The electric pump route is my last resort.