Gas in oil even after oil change?
 

Hey, I'm having a problem with my '82 GS 12a. I got gas in my oil somehow on the way to work. The car started off fine and drove like it normally does (no air pump, ACV block off plate just got here. Have to run it rich to keep it idling 'smoothly'). However, as I'm getting off at my exit after a 10-15 minute drive, I notice that my car is idling ~500 rpm as I'm coasting (reminds me of when my car was running leaner. Very rough idle and inconsistent.), and I can feel the car running rough through the shifter.

When I come to the stop light, I rev my car a little bit, and I notice that my car is missing BAD. I knew immediately what had happened: There was gas in the oil. I've flooded my car before and didn't change the oil until a couple days later, so I know how it acts when gas gets in the oil. Last time I got gas in my oil, it would only idle rough/miss in the mornings upon warming up (I guess it didn't get a whole lot of gas in the oil pan.), and would run normally above 3k rpm. However, my car now misses all the way through the rpm range (all the way up to 7k). I guess I had gotten ALOT of gas in the oil pan this time. When I pulled my dip stick, sure enough, there was gas. I thought that I was completely out of oil because the oil/gas mixture had dripped off the stick before I could even look at it (that's how diluted it was.)

After changing the oil, I started the car and let it idle a bit, trying to see if it would restore compression and start running normally. No go. It still got a shit load of gas in the oil. Is something wrong with my carb? I doubt it's flooding when I cut it off, because the car idled rough even after 10-15 minutes of trying to clear the problem up (spirited driving ;)). Could my rich fuel mixture be causing that much of a problem?

Gas in the oil is an indication of a problem, not the cause of it. Changing the oil will not fix it.

You are running way too rich, and or, not getting full combustion. I would start with the carb, from the sounds of it.

I just installed the ACV block off plate, and now I'm just waiting for the gasket I made for it to dry/seal. Do I need to wait for the RTV sealant to cure completely? Also, will it hurt the engine if I covered the whole side of the block off plate with RTV sealant, or will it likely not produce any problems?

Read the instructions on the tube.

ok, I was fairly wrong about the 'gas in oil' part. I changed my oil again to see if maybe the oil filter was holding some gas or something. However, after I draining the oil, I didn't smell much (if any) gas in the oil. I used some of that Castrol 'High Mileage' oil rather than what we usually use (still Castrol, just not a 'special type' of oil), and I noticed that it smelled a bit different than regular oil, so I'm guessing that what I thought was gas was actually just the different oil.

Of course, I still have a giant miss throughout the RPM range. I did fix the tiny miss (at least it seems like it) after installing the ACV block-off plate, so I'm happy about that. I just swapped out coils and took it for a drive, but the car still has the huge miss. It seems to get worse as the engine gets warmer.

Also, I'm unsure if this has anything to do with my problem or not, but whenever I just tap the gas a little bit, the engine RPM's will increase, hold for maybe a second, and then go back down. If I rev it to 2k and let off, it does this. If I rev to 3k and let off, it does it for a shorter amount of time, and at 4k and above, it revs normally. Is this indicative of a vacuum leak? I pinched off one of the tubes going to the filter box (the one on the passenger side behind the larger hose that goes to the grey box with a tiny filter), and the car doesn't have this problem.

One more thing: Should my engine/carb sound like there's wind constantly sucking down the barrels? Mine does, and I'm not sure if this is normal, or if I have a large vacuum leak somewhere.

How old are your distributor cap and rotor?

Probably as old as the car, but I've checked timing, and I've checked spark from every plug by hooking the timing light up to each wire and seeing if it lights up (which it did), so I think the cap and rotor are probably alright.

bump please >.<

The carb will sound like a tiny jet engine at idle (I can't think of any better similar noise maker). It sounds like your running way rich at idle for some reason. Fuel pressure? Float levels OK?(halfway up the glass) Spray some carb cleaner around the carb and vac lines see if the engine stumbles. Do you see any fuel coming from the bowl vent area? It's between the venturies and the fuel line attaching point. Check all these things if they are OK, I'd go back to checking ignition stuff.

The carb will sound like a tiny jet engine at idle (I can't think of any better similar noise maker). It sounds like your running way rich at idle for some reason. Fuel pressure? Float levels OK?(halfway up the glass) Spray some carb cleaner around the carb and vac lines see if the engine stumbles. Do you see any fuel coming from the bowl vent area? It's between the venturies and the fuel line attaching point. Check all these things if they are OK, I'd go back to checking ignition stuff.

I did notice that when I 'tap' the throttle from outside the car and looking down the barrels, the 'jets' (I guess they're the jets, they spray the fuel in) spit up some fuel sometimes. I looked at the fuel bowl, and it looks to be 3/4 full. Is this too much? I just tuned my carb by adjusting the idle mixture/idle speed and it's as good as it's gonna get.

Those are the booster venturies and yes the fuel goes through them. The little "V" shaped thing pointing down into the small venturies is where the accelerator pump shoots fuel. That float level may be a little high, did you look at both fr & rr bowls? You'll need a mirror to check the rear.

I'll check the rear after I go back out to do a compression check. I'm waiting for it to cool down, as I've been driving it around and experimenting, trying to see if I could notice anything I didn't notice before.

If I put it in 3rd gear and run it up to about 4k rpm, I don't hear/feel a miss. If I slowly push down the pedal, it won't miss either. But as soon as I floor it, the miss comes back. I also have a fairly large header leak that you can hear even more because of the miss. Could a lack of back pressure cause this 'miss'?

Doubt the header leak is causing this. Have you been checking the plugs(wet?) Sounds like to rich at the bottom then it clears up? Do you see fuel squirting from the accelerator pump jets when you move the linkage? I'm just throwing things out there now... These things are hard enough to diagnose with the car right in front of you, let alone 500miles away! If I was sure the ignition was solid I would take the top off the carb and poke around, not an easy task on a stock set-up. Easier to swap out a carb that you know is good if you happen to have access to one. Next time its missing shut it off right then and check the plugs this will tell you the most.

Well, it's missing all the time, that's the problem. There is fuel squirting from the accelerator pump jets when I move the linkage (I'm assuming this is with it cut off. When I let it warm up, cut it off, and then move the linkage, fuel comes out, but it doesn't actually go into the engine, it just sits on top of the 'throttle plates' and burns off/smokes.

The plugs did have carbon deposits on them the first time I took them out, but I cleaned them up the best I could and put them back in. Didn't seem to help much, if at all. Took the plugs out yesterday, and they're not wet.

I also did a compression check yesterday (with a piston compression gauge, though), but I don't think I used it correctly. I just spun the engine over and watched the gauge bounce, and on both, it would slowly bounce up to 75 psi (that's the highest it went). I'm going to try spinning it over 3 seperate times to get somewhat of a more 'accurate' reading.

If I can get this thing fixed by next week, I'm just going to go ahead and take the carb off and see if I can notice anything from there.

Do you think that recharging my K&N Filter would cause the problem? I sprayed a 'liberal' amount of the red dye/oil on it, and it looks like I might have put too much on it. There's tiny pools of it when I take the filter out, and I've noticed that the vacuum hose on the far right [while standing at the driver's side fender] seems to have some of the red dye around the mouth of it. If some of this oil got into a vacuum line or the engine, could it cause problems? I 'recharged' the filter maybe 2 weeks ago.

If its missing all the time I'd lean toward electrical stuff. Have you tried NEW plugs? Vacuum is either manifold or carb venturi, the air filter only sees vacuum coming at it through the carb. And remember the cars feed themselves oil. I'm stumped from here in FL but post anything you find out on the car it might spark something in my brain or someone elses.
I forget what compression is OK with one of those testers the main thing is that they are similar. An apex seal problem takes a third of your engine and doesn't clear up.

hrm... I was thinking earlier that it feels like the car has 2/3 of the power it used to have, but not 1/2 the power [which would indicate running on only one rotor, correct?]

I have been thinking about going out and getting new plugs, but I just replaced the plugs less than a month ago. I guess I'll just bite the bullet and try a new set.

Thank you for helping me out and giving me advice. I'll let you know if anything changes. (My dad will be home this weekend, and he may be able to offer a bit of insight on the problem.)

I guess I'll take a shot at this one too...:)

One thing to consider as far as your ignition goes; just because you have spark on all plugs at idle, doesn't mean it will be there under acceleration. This is due to a difference in demands. A weak coil might work at low RPMs, but when you put a real load on it it can fail.

If it were me, I would try swapping the coils around first.

Then a new cap/rotor (just because its still in one piece doesn't mean that it will conduct well).

Then I would take a good, hard look at the plug wires and the ones that go from the dizzy to the coils. Even if they aren't throwing off sparks at idle, they could be doing it under load.

One other thing to check at any point here would be your grounding. Just to eliminate that possibility, take some wire and run a line from your engine to the negative post and another one to the chassis.

It really does sound like an ignition issue, so any of these things could be relative. Good luck with it! :)

A wise man told me that 90% of all carb problems are ignition/electrical ;)

A very wise man, indeed. Most "carb problems" aside from flooding, crud buildup, or leaking, are actually traceable to an ignition or other electrical issue.

Sounds like a partially stuck apex seal. Power-foam the hell out of the motor and see if it helps.

Too much oil in the filter can work against you, filter clogs up faster and can cause an over-rich condition, then fouling the plugs . Cleaning the plugs can be iffy at best, I'd replace them. If the miss is still there after changing the plugs check the dist. cap, look for eccesive carbon on the electrodes or cracks in the cap itself, ck the wires look for gray spots, they could be shorting. I had a car with a hard to find miss once, everything checked OK plug wires looked good , just a little dirty, went inside for dinner and by the time I came back out it was dark, I started the car and opened the hood and I didn't even have to turn on my flashlight before I found the problem, the coil wire was lit up like a christmas tree. It was litterally glowing I replaced the wires and it ran great.

swapped coils, distributor cap (both caps looked fine), wires (for the plugs and for the coils), and sprayed around with some carb cleaner (doubt there's a vacuum leak. I hear no 'vacuum sounds'.) I'm going to go get some Sea foam from Advance Auto today after school.

The oil filter is new. However, one thing I did notice is that the new oil filter is shorter/smaller than the old oil filter. Would this make any difference at all?

I think he meant the air filter with to much oil.

Welp, it looks like my rear apex seal took a dump on me. https://www.rx7club.com/1st-generation-specific-1979-1985-18/%2Asigh%2A-shes-limping-wont-return-419073/ <--- Here's an explanation.