Since I've had this car (2001/driven 50K), it's had an oil seeping problem. I have one of those cast aluminum, fin-top valve covers. There's always oil in the groves. The left side of the engine, from the head down, always has a film of oil. And there is always a drop or two on the garage floor, probably dripping from the bell housing.

The csr is a B22 (big bore) and while it runs flawlessly, and I've managed to make accommodations for the overly large cam and resulting low vacuum, it has suddenly occurred to me after reading the manual page on PCV, and the odd, two-way flow it discussed,that my vacuum issue may have something to do with my oil weeping problem.

All the hoses are connected correctly per the factory set-up and the flame trap is clean. If anyone would care to comment on this it would be appreciated.

The standard oil filler cap often doesn't fit the hole very well in the alloy covers. Check that the steel insert doesn't leak around the join. New rubber ring and adjust the tabs on the cap. Glue the gasket to the cover with an oil resistant contact cement. Don't tighten the screws much more than snug finger tight.

On the steel tappet cover, I panel beat the oil cap whole into a better shape + bend the spring loaded cap part a little tighter.

PCV: I like to use the B20 metering orrifice which feeds into the middle of the manifold & feed it from the oil separator on the side. The house on the cap I connect to the air cleaner, or you could use the popular K&N directly on the cap as is popular.

Dave;

Oil on the valve cover fins can only come from the Oil Filler Cap...if you have the correct Oil Filler Cap for sealed PCV Sys installed see: https://www.sw-em.com/pcv_diagrams_and_notes.htm ...yours would/should be, the right Cap shown under Oil Filler Caps, there should be NO leakage possible, as everything should be sealed...I'd first verify it seals well to the Valve Cover (this might require adjusting the two bayonet fingers). Check also sealing rubber gasket is present and being loaded up when the Cap is twisted home.

Good Hunting!

You're causing me to have flashbacks to all the oil cap issues I used to have on my B18. I agree with Ron about making sure the oil cap rubber gasket is fresh and the bayonnet tabs are tweaked as needed to maintain a tight seal. Those rubber gaskets often start out nice and plump giving a good seal, but as they age quickly dry out, shrink and get brittle. At the same time make sure you've got a good valve cover seal. The flared edge of a stamped valve cover can easily get a bit warped or misshapen if the nuts are unevenly tightened or overtightened. With appropriate blocks of wood you can hammer them back into better shape when needed. The original valve cover gaskets were a relatively thin cork that would also dry out with age. A newer, thick, good quality flexible valve cover gasket, possibly with some added RTV gasket sealent at the corners if you're desparate, will also help any oil seepage you see around the top of the block.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now

Have you tried to do a complete oil flush?I did w my 93 940 driving s;low at 30 mphs for a 1/2 HR. W 1 GQT OF KEROCENE TO CLAN ALL PASSAGES
i DID & HAD NO OIL LEAKS FOR 6 MOS..

If you want to flush out an old engine, use HIGH DETERGENT MIXED FLEET Diesel oil which has ZDDP in & use the double sized Ford Filter or similar Nissan & Datsun filters. I've never used anything BUT this combo.

Look for oil that can be use in Volvo TD100 & TD120 pushrod engines. These are 10L & 12L Turbo Diesel with the same style cam & lifters as B20.

In the 1980's and early '90's I used Shell Rimula-X 15W-40 religiouly because they released advertising which specifically stated: 'MEETS & PASSES VOLVO CAM AND TAPPET WEAR TEST'

Your B230 does not have this cam arrangement, nor does it deliever the BMEP of any decent B18B.

It's not a B230, it's a B20 with a big bore rebuild. That's why I referred to it as a B22.

Dave, that was a reply to Blindboy suggesting putting Kero in the oil of a B230. He's an idiot or a troll.

What cam have you got? Most of the older grinds will allow for you to open up the tappets if you have gone too big.

The B20 PCV System is the way to go, I've even used it with 2x48DHLA's and a giant cam.

Getting a stock tappet cover & painting it black would be a step forward over the poorly designed cast aluminium POS too. The top is designed to steer oil back over the spring & keepers where it is needed. Poorly designed bling does nothing good.

Not sure what the cam is. Was rebuilt by the P/O in the early 90s and while I have have some records, they don't indicate the "size" of the cam. Know it was "blueprinted," ported and polished, and a big bore kit installed. Since I have the normal aggressive cam symptoms: needs high idle speed (1050-1100 rpms), torque is lower than my previous '72 with stock B20, smells rich when running and gets only about 20 mpg and, of course the vacuum at idle is screwed up, I have to assume he wanted the biggest cam possible. I've had to add a vacuum pump (Pierburg, runs off the cam) and a vacuum reservoir, along with a gazillion check valves, to help with braking. Actually never thought about messing with the valve settings. If you could give me some guidance, I'd think about experimenting with that.

Only problem is that after years of fussing with it and making adjustments to compensate for the cam, including running fuel pressure at 32 lbs, the thing does run beautifully and is now a pleasure to drive. So maybe I should just count my blessings. I only put a couple of thousand on it every year, so gas price isn't an issue, and only people behind me can smell the stink

As to the valve cover, you make a compelling argument about the proper oil distribution. Perhaps I'll dig out that old cover and have it powder coated. I'm sure Planetman could supply me with a decent gasket.

Most likely your 'Big Bore' is one made of IPD bits, the cam would be Isky's VV71, .020" tappets cold is 1st thing. Does it have dual springs?

Compression test next & check ignition timing runs from 10° @ idle & runs to 32° maximum (around 3500rpm)

Next, see if the idle mixture knob on the back of the ECU does anything. 32psi would make it fairly useless.

The MPS, take the hose off & check it for cracks, the stick it back on the MPS, suck on it & see if it leaks.

Does the MPS still have the epoxy bung on it's end untampered with? This is three way adjustable before the end is covered in epoxy & the place to get extra fuel for full throttle & also the place to lean out the cruise mixture.

The 'TPS', is it set properly?

The D-Jet system is actually fairly simple, but is limited to 30% more fuel with MPS adjustment.

Also, Increasing the fuel pressure doesn't work well for suppling more fuel because the injector sprays on the back of the HOT intake valve & vaporizes. This is great for emissions, which was the whole point of D-Jet, BUT, vaporized fuel take up a large amount of space limiting how much air/fuel goes in the cylinder.....

Back to tappets, do one at a time. When you see inlet valve 4 go full lift adjust inlet 1, etc. This is the 2nd most accurate way & you get to see if a lobe is worn badly (It's visually obvious)

Oil leaks: There is nothing wrong with the stock gaskets. They leak firstly because people overtighten them down. 2nd, the oil cap area gives up a bit over time. Both can be panel beated back again. I paint my things with regular old enamel & a brush. The engine heat bakes it on fine. It's well worth painting the crank pully black too, bake that in the oven, then put some liquid paper on 0, 10, 20, 30 & 35° lines. When setting the timing make sure maximum is between 30 & 35° when you give it a quick flick up to 3500-4500rpm. I feel that even with IPD's 'Big' cam, it should idle smoothly at stock idle with 10° BTDC.

Many thanks for all the tips. TPS and timing are good. As to the pressure sensor, it's stock. I have a couple and have "experimented" with one which has the epoxy removed. Unfortunately in reading about how it functions, I'm just not saavy enough to figure out how to play with those adjustments (actually thought there were only two adjustments-the small center screw and the large travel limit plug). As to increased fuel pressure, that was a tip from this forum and it was the one thing that really made a huge difference in smoothing things out.

I may try the valve adjustments you suggest, as that can be easily undone. It doesn't have double valve springs. While I've used WhiteOut on the crank pulley timing marks, I will re-do that after first giving that quadrant a spray of flat black. Great suggestion. Wish I'd painted the whole thing as you suggest while I had it off to replace the front seal.

TPS: When you say the TPS is good, are you telling me that the knob on the back of the ECU alters the idle mixture?

MPS: The bung is the full load stop(zero vacuum), there is a 'screw in a screw' arangement in the diaphragm. The bigger slotted screw stops the diaphragm in the opposite, high vacuum, part throttle position. The little screw in the middle shifts both at once.

The aneroid component is the part that does all the work in the cruising & mild acceleration situations & does some barometric correction, although I don't know how much altitude correction it is capable of. This is the part that hates a rough idling cam & can crack, but you'd know immediately because it will go full rich, same as a cracked & leaking diaphragm.

Adjustment: The three screws have the same pitch. On my 164, I didn't adjust the slotted screw. I put a spacer in to allow more overall travel, adjust the small screw back to where it was originally, in relation to the transformer end.

On a dyno hold it at full throttle 4000rpm, then see if you can adjust the bung outwards enough to get the mixture right. Let cool for 5 minutes. Now repeat an adjust the timing. Let coll for 5 minutes. Now do a full sweep in acceleration mode from 3000 to 6500rpm. Get your print out. This is as good as it gets without opening the ECU up.

If you have any real performance above a stock B20E, you won't get as much fuel as you need. With a stock B20E, complete with the HQ 2.125" as seen on 140's, fixing the exhaust will give you more HP than you can get out of D-Jet WITHOUT a stupid cam.

Cruise mixture: You can lean this out as much as you like! But, too much gives an annoyingly slow throttle response. On my old 164, I leaned cruise mixture out so much it needed half throttle to do 60mph, but hard to drive. I put it back to close to stock.

(At cruise speeds you can easily run the gauge completely off the scale. This is why modern engines have electric throttles & wide band O2 sensors.)

Camshaft: It is very likely that your cam is "single pattern" meaning that that the intake & exhaust have the same profile. After you run through the adjustment, rotate around until either 1 or 4 are visually at 'equal overlap', meaning both valves are open an equal amount. A 'blueprinted' engine would have the cam degreed in to around 4° advanced, so you should see that at the crank pulley close to the 5° BTDC mark. If it's got 8 full lobes & timed somewhere between 0° to 5° BTDC, then it will do. Look at both 1 & 4.

'Visually': If your engine was properly built to 'as new' & 'blue printed' condition, all the retainers will be at the same height, you can see this if you take the rocker arms off & stick a straight edge across them. If you assume this is correct, then a short straight edge across the pair of spring retainers for one cylinder will give you a good idea.

A Better Method: Set the crank to TDC 1 & 4, which ever one is in the overlap position, loosen the tappet adjustment to zero, rotate 360° & stick in enough feeler gauges to fill the gap & tally that number up. Repeat on the opposite cylinder.

Ideally, when checked at TDC, you should have .020 HIGHER lift on the inlet than the exhaust. ('Straight Up' with a single pattern cam means both valves have the same lift at TDC on overlap)

Best Method: Degree Wheel & Dial Indicator, this will tell us what cam you actually have in it.

I wish you lived around here (Lititz, PA). Much of what you suggest is either beyond my ken, my ability equipment-wise or exceeds my current level of ambition. Certainly it probably wouldn't do much good to cherry pick your suggestions. I did take your advice on the valve cover and purchased a powder-coated original and a new gasket.

Though you've convinced me that taking ALL the steps you mention would probably result in a more properly running car, I've been fighting my urge for perfection in things and just enjoying the fact that it runs extremely well and is very "driveable." Essentially I'm in "if it ain't broke, don't fix it" mode. However, I'm going to document all of your advice and if things start to go south I'll enlist some professional help and give them your list.

Meantime, with all the really smart people who own, or have owned, D-Jet cars, you'd think someone would have cobbled together a solid state replacement for the MPS. Perhaps not for commercial purposes, but just as a project to be shared.

How did you go? Does the idle mixture screw on the rear of the ECU function?


I've had a few thoughts.

"Meantime, with all the really smart people who own, or have owned, D-Jet cars, you'd think someone would have cobbled together a solid state replacement for the MPS."

I thought about replacing the end piece with an encentric piece connected mecanically for the heavy throttle positions & keeping the aneroid part for the rest.

The transformer end is a big piece of the ecu component, impossible to get rid of.

The ipd dial a mixture knob schematics are available, I thought about trying to replace it with a pot & connecting that mechanically.

Ultimately, you can use all the fuel that D-Jet can provide without altering the intake side of the engine. Some exhaust port work, a bigger exhaust lobe & a decent exhaust system will use up all the fuel an altered D-Jet system can provide.

If you want, MegaSquirt is the way to go, it can replace your ECU, TPS, MPS & the trigger points in the distributor, BUT, the intake manifold is still wrong.

ALSO: 36psi? How did you get it? I can't see it doing anything but running super rich at idle UNLESS you used a vacuum referenced regulator.

I noticed that there is such a thing found on Datsun 280Z cars which have Bosch style injection. I would have liked to have tried that back in the day on my 164.

If you can find it, K-Jet from 1974 car works well & will feed a decent engine(BUT the intake manifold is still wrong)

Recently I got a proper length Twin DCOE manifold & thought about combing it with MegaSquirt + the D-Jet parts + a couple of old 45DCOE's functioning as the throttles, but I thought f**k it & bought a pair of new 48DCO clones. Tuning those is a piece of cake. The only reason I would force myself to modern injection is for a blown donkey & I'm not in to boosting things.