My 2.4L is now a 1.8L ... Huh.

A couple days ago, I decided to get to the bottom of my carburetor questions. I don't know a whole lot about carburetors to begin with, but I have a phone, the Internet and good friends who are smarter than me, so I figured I could sort out whatever was wrong with consults as needed.

I need to thank a couple people before I get into what I found. Danny, Stan, Warren Miles and whoever wrote the little yellow Dell'Orto pamphlet with the exploded diagram for the DRLA series -- thanks for the assist.

I have had three pairs of Dells since I traded away the 34 Solexes that came with my old 1641cc engine. I first (very briefly) had a set of 40s, a set that acted like and were marked as 48s but the bases of which had been hogged out long ago in Italy to 51s, and now I have a nice set of straight-up 45s. Again, received in trade.

A few weeks back, I put the car on the highway and ran it up to normal cruising, 65-70 or so, at maybe 3500 revs. After about a half-hour, I started getting a rhythmic popping sound from the pipes. I figured it was the same fuel-cell foam garbage I've been cleaning out of my idle jets for a while now, so I pulled off and cleaned them out. No joy. I decided also to move the carbs up on the priority list, so this week I set aside a couple hours to learn a thing or two about them.

I read here about the drowning symptoms other folks were having, ruled them out but called a local guy who had a set of 45s and asked him if he was willing to trade. He really likes dithering with Dells, so we worked a zero-dollars deal and swapped. I observed these carbs running on a Bug right before they came off, so I figured that was good for a starting point.

I would chime in here, but you know my skills. If you need to know how to turn the car on, let me know...

Good to hear about your carb progress--I hope it ends up well for you.

Cory---where can that yellow Dellorto pamphlet you mentioned be found?

Thanks!

Actually keeping carbs in good shape is simple, and I have become an expert on it.

Step 1: Curse fluently.

Step 2: Look pitiful.

Step 3: Ask Danny Pip for help.

Step 4: Have another beer.

Works for me.

I'm waiting for the end of this story, the topic line sounds ominous...
Since when do you have a 2.4? I thought you had a 2.6 or 2.7?

The car has been running well from about 2800 to 5000 revs, but was stumbling at idle and falling off at the higher-than-5000 range, so I've been puttering around at more moderated speeds until I was ready to take the car off the road for a while. I forced myself to park it after I took it to a specialist in Annapolis (Tif's) and he couldn't figure the funky nature of the problem after a quick look.

With Tif over my shoulder, I showed him how little a difference there was in the car's idle when I turned the mixture screw on number two cylinder in all the way. With Dells, the screws and jets are all yellow metal -- brass or bronze or something -- so you have to be nice to them; 'in' means just snug, which I've always been careful to observe with the 48s. No change at all. I did number one next. That caused a stumble and a stall, so I reset both screws to 3.5 turns out, a full turn further out than where I usually set them, but that was Tif's advice.

I set the three-four side the same way, just in the interests of uniformity. I put my trusty snail on the throats, and got seven, zero, seven and seven pounds. Tif adjusted the idle screws on each, I tightened my linkage and synchronized the carburetors that way. That's a little out of order from what I later did in my garage, but I didn't want to completely dismantle everything while it was in Tif's parking lot.

Rather than mess with it too much more (he had customer cars to take care of, and I was asking for a favor), I took it home and parked it. I dismantled the pieces that needed to come off for the swap, took the carbs off, cleaned the mating surfaces and took off the trumpets and air-cleaner bases, plugged the banjo fitting holes and wrapped them up in oil cloth.

I called the guy with the 45s, figuring I'd rather pull that trigger and see what those would do -- I wanted them anyway -- and I'd keep the jetting more or less the same after changing them out.

I kept the idle jets and the main jets I had in the bigger carbs. He had a few different sets anyway, so he was cool with it. I brought the 45s home, installed them, hoped for some stupid reason that that would solve my problem ...

So? You have a spare 1.8 laying around your garage? A substitute engine?
Oh, being a recent convert to the Del-scene, could I be so bold as to ask for a copy of the "little yellow book"?

... But no. It didn't.

So ... If I was going to figure out why I got 7-0-7-7 with the 48s and now the same thing was happening with two completely different carburetors, either I was doing something completely ass-backward or the problem lay elsewhere. Stan's consistent advice, that it has to be mechanical, spark or fuel, made sense.

Eliminate fuel. The pump is working fine, the lines are clear, the jets are clean and the carb over one and two worked perfectly when I switched it to the three-four side and vice-versa. Huh.

I tried the phone-a-friend route with Danny -- whom im sure had better things to do than act as a spiritual advisor at 10 p.m. Disconnect the linkage and run the idle up, open the mains up until the throat for number two opens, then adjust one to where it and two are close, he said. I tried it. Nothing. Butkis. Nada. Still exactly NO draw from number two.

Stan, who also certainly had better things to do, suggested pulling the plug wire to see if it was sparking. It was. Now, from the top of the carb to the top of the head, the carburetors have been eliminated as the source of my problem. I'm now looking at something mechanical.

The plug is sooty and a little wet. I will buy a new set of plugs Sunday and try firing the car up again. If that doesn't work, since my MSD was throwing sparks across a gap as wide as a Cundiff field goal, I will have eliminated fuel, air and spark. I swapped the existing plug for one from a box of leftovers from my last tune-up -- not new, just a different used plug -- and it didn't make a whit of difference.

The game plan for this weekend will involve removing the plug again and checking compression. Stan and Danny both suggested the 'put your finger in the hole' baseline test, and since there ought to be 100 psi trying to escape when the engine turns over, I'll disconnect the coil and ask a helper to turn the engine over with the starter.

If my finger gets popped out by air pressure, great. If not, it'll be mechanical and I'll have to pull the head. I'll be looking at a valve seat, piston rings or the valves themselves.

We'll see. Until Sunday, I'll have to be happy with an excellently carburetted 1.8L engine.

Jack, I'll Xerox and mail you a copy of that pamphlet. Could you e-mail me a refresher on your info and add a good phone number to call you on? Thanks to Warren, it's already been duplicated for my library.

And, next time you talk to Russ, tell him that for about the next week, he might be able to beat the Sloppy Jalopy in a run-and-gun with that bitchin' targa! ;)

Rich, I currently have three cylinders.

At 104mm by 71mm times pi times three (or whatever), I'm now down to three quarters of my intended 2424cc's ... roughly 1818cc's.

She's still a bad mo-fo, but not anywhere near what it should be. And I'm not driving it until it's fixed -- unless Russ Crosby stops by for a grudge match. ;)

I'll probably scan the pamphlet and add it to the library on this site, if there's sufficient interest and if I can figure out a way to get it done with sufficient resolution as to be useful. If I can't figure that out then yes, I'll mail one to you. I found it to be very useful.

Corey..... Do you have an absolute "0" on the one cylinder??? I've seen this happen three times.... Rockerarm failure.... push rod failure.(normaly quite noisy)....and the head snapped off a piston and lodged in the full "up" position.... Let's pray for either of the first two....

You should have had some reading if the intake was opening on a sound cylinder, even though it was not firing....

I feel for you buddy....Been fighting mine for over a year.....GOOD LUCK!!!!

Ah, I was afraid you were going to describe your intentions that way...75% of normal is not a good thing. Regards sufficient resolution on scans etc. Do you actually have some form of Photoshop? Perhaps I could help you on that topic?

Leon, complete zero. I'll take the cover off Sunday and have a look. I want to try the finger test first, before I crack anything open, then I'll see what's going on with the rockers.

Rich, I'll mail you a good copy to scan. Thanks. E-mail me an address?

At absolute zero, you have no draw... Even a dead spark plug/plug lead should give you a little tiny bit of pull by virtue of the piston banging around randomly in a closed hole (as you proved the carb works by swapping positions).

Really going for a mechanically dead hole. You didn't mention any copious blow-by or chuffing sounds, so most likely your intake valve isn't opening.

**PS - I don't know pa-too-kus about VW's so dont listen to me but if I'm right, do I get an egg sammich? Not that I could actually eat it but I could share it with Steve.

angela

Curious statement Angela...... How do you share an "eggsammich" if you dont eat it???

Inquiring vacuums want to know...... 8-)

Cory, what comes to mind is a similar problem that I had with a twin-cam Mitsubishi motor that I just loved. It exhibited the same symptoms as your motor, so I took it to a mechanic friend who changed all of the sensors, charged me $200 for parts, and sent me back home, stating that the ECU will need to relearn, and the engine will be running fine in a week. Not so.

I knew that it was running on 3 cylinders, and really quite well on the 80 mph drive from Wichita, KS to Houston, TX. Finally, after dark one evening while in Houston, I popped open the hood and removed the cover that lay between the two cams where the spark plugs lived down in some deep holes. I laughed with delight by the spectacle. The high voltage for the dead cylinder was arcing straight through the rubber plug and grounding into the valve cover. With $0.05 worth of electrical tape around the rubber spark plug connector, I again had a very smooth 4 cylinder motor.

The moral of the story? Just because you see spark going through the plug wire does not mean that it is going through the spark plug. Check the running motor in the dark to verify no spark arcing.

Good luck on the fix and I hope that it is does not involve some expensive metals.

"the head snapped off a piston and lodged in the full "up" position"

Now THAT would be cool ! ! !

It could just as well happen, if the head were up high enough the rest of the piston would rise and fall and stabilize on the rings and who would know beyond the initial separating noise.

I LOVE that scenario ! !

Best part is that, going along with modern multi-dimensional/ quantum mechanics theories and such, Cory's engine and Leon's hypothesis kinda follow along with Schrodinger's Cat. The piston HAS lost it's top AND hasn't lost it's top. BOTH realities are occurring at this exact same moment to our universe outside the cylinder barrel. It's only when the head is removed and viewed that only one of those states of existence will remain.

It isn't either or but both until external observation has been made.

So that means there are at least two parallel universes related to Cory's piston having or having not snapped off, correct? Oh Lord, that means there are at least two Cory's and two Hooptys! My head's gonna explode.

You guys are making me feel much better.

I'm THAT guy, you realize. I have a pretty great wife, a pretty decent place to live in a nice neighborhood, both of my jobs are awesome ... And none of that really matters to me right now, because my car is broken.

Anybody else could patiently wait for an opportunity to take it to a shop and have someone else take a look-see, but I have to have that car at 100 percent mechanically sound or my addled brain just goes nuts thinking about what could be wrong with it.

In this case, I'm glad you guys share that affliction -- at least to some degree. Thanks for the suggestions on what to look for. I'm pretty glad that I won't have to remove the engine from the car to do any of this inspection, and in a way that helps to validate the removable rear body section.

Meanwhile, I'm at work until Sunday morning. My mother-in-law is inbound Sunday, but she's pretty self-sufficient ... So I'll be hunkered down in the garage with my tools, some great music, my coffee pot fired up, maybe a cigar. Depending on how long I'm monkeying with it, I might even crack open a barley-pop or two.

For you guys new to this hobby, there's an object lesson here. About ten years ago, maybe more, I didn't know a damned thing about my car. I hadn't ever had a Volkswagen Beetle, my Porsches had been serviced by professionals and I counted heavily on good scoop and discussions from SOC folks.

I feel like the advice here, and the friends I've made driving that car all over the eastern half of the U.S., have been hugely beneficial to me. Throwing down a couple words now and then about bumps in the road for y'all's amusement and helpful advice is absolutely worth the price of admission.

TC, does my d

Cory

Didn't you recently play with the valve covers and have problems getting them to fit?

Just a thought.

As for sympathry, my fanshroud is at the painter, the alternator is in the basement and the car is under cover. Here's hoping the new additives help with ethanol so we don't lay Dellorto rebuild this year. I think I'll bring a rebuild kit to Carlisle.

Paul

This may be a reach, but have you checked your valve clearance on that cylinder?

It sounds like you have a valve stuck open. THAT can be checked by getting a spark plug fitting to let you apply compressed air to the cylinder and then (a.) see if it holds pressure a bit and (b.) if it doesn't you'll hear the air whooshing out of either the carb or the exhaust.

Stuck valves are not unheard of in T-4 engines.

I'll be checking that also, Gordon. Thanks for the consistent good advice!

Paul, everything fit as advertised, but I'll know whether I screwed up Sunday morning. I'm planning on working on this until I positively identify what's not right.

Id pull the hesd on the problem side and just take a look see.. Replace only what you have to..

Ah, when were you driving without oil just awhile back? It's not the checkerboard paint is it?

TC...... Whatever your using..... " Dont Bogart that whatever"..... Corey could use some to hold it together until repairs are made, and I could use some on general preciple.... 8-)

Leon - I wrote my thought poorly. I meant that I couldn't eat a whole egg sammich but I could share one. There's just too much egg in it...

angela

Cory, thanks for the tip on Lincoln Drake. We live in the Maize school district, so he would just be up the road from us. As soon as we get a nice day in the Spring, I will fire up my Speedy and drop in to say Hi. Right now, it is 12 degrees F out.

Just shaking your cage Angela.... 8-) Don't take anything personally....

BTW Cory, it is spark, fuel and compression. All three must be there for a cylinder to fire. Since you know that there are spark and fuel, put a compression gauge on the cylinder and verify that there is or is not compression. No compression at all will usually mean that there is a valve not closing for some reason. Gordon is on the right track and way ahead of most of us.

If an exhaust valve is stuck closed, then the engine will "puff" or cough up through the carb throat because the compressed gasses can't be expelled out the exhaust port and have to go somewhere so they go out through the intake via the valve overlap. Put your palm on the throat horn and it'll push it off.

If an exhaust valve is stuck open there will be far less downdraft on that half of the carb throat, because the piston is pulling gasses in from the exhaust side when it shouldn't be. Can't remember what the spark plug should look like, but it won't look like the others. You should feel almost nothing going on when placing your palm over the throat horn. The plug may be a little sooty, but shouldn't be wet because there isn't enough vacuum in the venturiis to pull any fuel into the carb. A Unisyn or equivalent will show nothing at all going on.

If an intake valve is stuck closed, there will be no activity at the carb throat at all (you'll feel nothing when you push the palm of your hand over the top horn - it's supposed to periodically suck on your hand) and the plug will be dry and little or no soot.

If an intake valve is stuck open you will feel pressure in both directions when placing your palm over the horn, because the piston will be both pulling and pushing through the valve/carb. Using a Unisyn or equivalent, you should see something going on and the needle/indicator will fluctuate wildly.

Hope this helps.

BTW: You can do a compression test, but I think it'll show either nothing (no compression) or be inconclusive. Better to borrow a spark plug compressed air fitting and try to pressurize the cylinder (you might be able to use the bottom of a compression tester to do this - at least mine can be adapted that way. This must be done with BOTH valves closed ( looking at them under the valve cover and rotating the engine until they both close, just like when you're adjusting them). Then you can hear where it's leaking.

If an exhaust valve is stuck closed, then the engine will "puff" or cough up through the carb throat because the compressed gasses can't be expelled out the exhaust port and have to go somewhere so they go out through the intake via the valve overlap. Put your palm on the throat horn and it'll push it off.

If an exhaust valve is stuck open there will be far less downdraft on that half of the carb throat, because the piston is pulling gasses in from the exhaust side when it shouldn't be. You should feel almost nothing going on when placing your palm over the throat horn. The plug may be a little sooty, but shouldn't be wet because there isn't enough vacuum in the venturiis to pull any fuel into the carb. A Unisyn or equivalent will show nothing at all going on.

If an intake valve is stuck closed, there will be no activity at the carb throat at all (you'll feel nothing when you push the palm of your hand over the top horn - it's supposed to periodically suck on your hand) and the plug will be dry and little or no soot.

If an intake valve is stuck open you will feel pressure in both directions when placing your palm over the horn, because the piston will be both pulling and pushing through the valve/carb. Using a Unisyn or equivalent, you should see something going on and the needle/indicator will fluctuate wildly.

Hope this helps.

Start by checking the valves on that cylinder - it sounds like the intake side has loosened up and backed off.

BTW: You can do a compression test, but I think it'll show either nothing (no compression) or be inconclusive. Better to borrow a spark plug compressed air fitting and try to pressurize the cylinder (you might be able to use the bottom of a compression tester to do this - at least mine can be adapted that way. This must be done with BOTH valves closed ( looking at them under the valve cover and rotating the engine until they both close, just like when you're adjusting them). Then you can hear where it's leaking.

I'm with Gordon: Exhaust valve stuck open (or seriously burned), Intake valve stuck closed, or hole in the piston. Or you could have a major intake manifold leak, maybe at the head; but you would have found that already, right?

Any of the first three are ugly, but you can go through process of elimination relatively easy; with a leak down tester. For that matter, as big as you say the problem is you can just use compressed air.

If you have a rubber tipped air blast nozzle, hold it tight into the bad cylinder's spark plug hole. But first, roll the engine over to tdc on that cylinder. Using LOW pressure (15psi) load the cylinder with compressed air. You will be able to definitely hear where the cylinder is leaking.

If you have something wrong with the exhaust valve you'll hear the air escaping by listening to your exhaust pipe. If you have a hole in your piston (or bad rings) you'll hear it by listening to the crank case through the oil filler.

Of course, before you do any of that you should have taken off the valve cover and visually watched the valves going up and down, and checked valve lash.

I am a firm believer that it is not the worst you can imagine until you prove it to be so. It sounds to me like you have a couple of problems (1. fuel starvation after 30 minutes freeway, 2. dead intake vacuum on one cylinder). Fix #2 first, then tackle #1: If you have one of those silly fuel pressure regulators like I do, then make sure you have enough flow through it to keep the float bowls full at sustained high rpm on the freeway. (Been there, done that, ugh!)

Cory -- see if this sounds familiar.

You rip up the freeway onramp banging 5000 rpm shifts. Then the engine falls on its nose, runs rough, backfires through the exhaust and becomes generally evil. So you pull off the freeway and look at things with the engine idling (poorly) like it is running on two cylinders and then for some reason things seem to smooth out. So you get back on the freeway (more timidly) and things seem to be ok for a while until you notice intermittent popping from the exhaust becoming gradually more frequent.

If you've got one of these: http://www.carshopinc.com/images/MRG/9710.jpg Then disconnect the fuel line from the side of the carb and run the fuel pump (with the fuel line emptying into a vacant 2-liter bottle or something. Notice the fuel flow amount during 30 seconds. Then open the regulator to 5 and repeat the test for 30 seconds.

In my case I absolutely do not have enough flow to keep the float bowls from starving if I set the regulator for 2-1/2. I set for 3-1/2 and have no problems. Your results may vary. (More than 3-1/2 I think is definitely pushing it.)

Gentlemen, thank you for the consolidated checklists. I'll be obtaining metering equipment in the morning, and using it as soon as I get home. I'll have results before my mother-in-law arrives at one, I'm sure.

Mark, I'm 99 percent fuel delivery isn't the problem. It's been at three pounds since I installed the electric pump. I'm going to concentrate my efforts on the valves and compression first, since that's indicated for the problem. If I can't eliminate that as the problem and have to continue looking, I'll get that gadget and verify pressure.

I have a sneaking suspicion that it's got a lot to do with my valve assembly. The stumble evens out above two grand, and I haven't had any freeway-related problems at all. My stethescope didn't pick up any noise from the case itself, but there's a bit of tapping going on inside the valve cover that's new to my ear.

That was Thursday night and into Friday morning, though, and I was tired and maybe a little frustrated. I'll be on it like a bum on a ham sandwich tomorrow morning.

Thank you guys again.

Cory -- just a last note on the fuel pressure regulator: It's not the pressure, it is the flow volume. If you have a regulator like the one I linked, then when you cut pressure you also cut flow. 3 may be enough pressure (actually 2-1/2 is enough pressure) but it might not be enough flow.
For me 2-1/2 is definitely not enough flow, and I think 3 would be iffy. As I said, I'm at 3-1/2 and I have been ok ever since.

Good to know. Ironically, Fred McKenney (whose car I've been messing with for a short while, just called me from the road to say he's elated.

I asked him what he was doing tomorrow, and he says he figures he'll come on over with his compression equipment, metering valve and air.

I must be Irish.

hmmmm...... "Drake"

Irish? well..........

Anyway, mentioned your problem to a couple of intellectuals at the local car club Oyster Roast this evening and one simply stated the obvious:

"Sounds like a broken valve spring on an exhaust valve."

Wish I had thought of that.

Perform a leak down test @ TDC and see where the air leakage is from.. Then you will know where the problem lies. Pop off the oil cap and listen for air, then listen to the intake and the exhaust and see where the leakage is. Compression tests tell you that a problem exists; couple that to a leak down test and pinpoint the issue.

Maybe you lost a lifter? Maybe dropped a seat? It sounds internal.

Thanks, guys. My plans have now shifted to Monday for pressure tests, but the visual inspection will still happen before Teresa's mother comes in tomorrow.

After I get her settled in, I'll be coming back to the station for another overnight. Overtime ... Which will I will probably be buying parts with. Jake, thanks for the insight. I know you're a busy guy.

Gordon, me great-grandmahther's maiden name were Sullivan, ya see. Irish it could be, but in parts. I'll be sure to look for a broken spring. Thanks.

Hey, Cory, is it possible that the new tapping you hear from the valve cover is a REALLY loose intake valve? Maybe you just need to adjust the valves correctly, and your problem may be solved.

Don't take this the wrong way, but it seems you always have some trouble after a valve adjustment.