Dave’s Holiday 55

I got my 55 Super 88 back from the shop on Monday of this week. I originally took it in to have some noisy valve lifters replaced. After opening up the engine, the mechanic called and wanted me to come to his shop to see what he had found. The camshaft was pitted and nasty looking. He recommended replacing it. So after a quick call to Fusick and a week of delay, the new camshaft and associated gaskets arrived and were installed. Of course, the carb needed to come off to get at all the parts. And since the valve covers and intake manifold were off, I took them home and painted them with original? green color. When I got the car home I noticed that the acceleration in fourth gear was very sluggish. Low gear acceleration was fine. Driving along in fourth gear, I found that the passing gear was non-existent. So I got out the service manual, followed all the steps to adjust the carb and tranny linkages. Clevis H, rod A, etc. Test drive yielded no improvement. I noticed a machined hole in the spacer under the carb that I hadn’t seen before. Is it possible that the spacer was installed backwards? Could that cause a linkage problem? Is there a vacuum hose that is supposed to be in that hole? Any and all suggestions would be appreciated. By the way, my wife is a little miffed that I spent “all that money and it still doesn’t run right”. Her Christmas list got longer after she found out what the repairs cost.

fleming442

Got a picture of the offending hole? An open vacuum nipple will make a nasty leak and cause major problems. You can throw a cap/plug over it and readjust, but I'd want to know what is actually wrong. Did they leave a hose unhooked?

Tedd Thompson

I wouldn't think there would be a vacuum line attached to the base gasket, we are talking about a thick 5/8 thick gasket made of fibber type material. Its main purpose is a fix for vapor lock, and I don't remember ever seeing one with a vacuum line attached.

Have you tried plugging the hole with a bolt or screw and see if that helps? As an afterthought, does your vacuum advance inside the distributor rotate with a increase of vacuum?... Tedd

Dave’s Holiday 55

The hole is in the center of the spacer under the carb. As stated before, I don’t remember seeing it there before the work was done. I looked for an unattached hose but didn’t find one. And Tedd, how do I check for the vacuum advance that you mention. Just to be clear, the car will speed up in fourth gear but it does so very reluctantly. If I had to zoom out of the way of some crazy driver, I’d get hit.

Dave’s Holiday 55

And I still need to touch up the paint on the intake bolts.

redoldsman

So the car has an Edelbrock carb with a spacer under it. Edelbrock carbs meke the tranmission linkage more difficult to adjust correctly. What I see here is a spacer missing a plug and that is creating a huge vacuum leak. The car will never run right until that hole is plugged. Crank the car and then put your finger over the hole. You should notice a significant change in the idle. It doesn't appear there is a gasket between the spacer and the intake manifold. If not, you need one. If you don't have a vacuum gage, I suggest getting one. It is one of the best things you can have in your toolbox when you have one of these old cars.

Tedd Thompson

Suck on it, that is the vacuum hose, that is after you have removed it. If the diaphragm is leaking, you won't be able to hold a vacuum with your tong. Tedd

Dave’s Holiday 55

OK. I checked the vacuum line to the distributor and I was able to maintain a vacuum. The tube did not taste very good. I also had the engine on low idle and removed the vacuum line from the carb. The engine promptly died. While it was running again, I plugged the hole in the carb spacer with my finger. There was no noticeable difference in the sound or the RPMs. I can’t tell if the gasket is under the spacer. I guess I’ll raise the carb and spacer and look. If it’s there, I hope it hasn’t been glued. I’ve also included a picture of the carb linkage. Maybe someone will see something that’s not right. But, hey, I never claimed to be a mechanic.

maineolds

Im not saying you have a vacuum leak, could be but your problem could be many things. But if you suspect a leak there are a couple easy ways to test it. Scotty Kilmer on Youtube suggested getting a cheap cigar. Light it and see if the smoke pulls in as you move it around the engine and carb. It works!
Another way to test is to spray small shots of starter fluid in suspect places. This method also works but can have some negative affects. Sometimes starter fluid can mess with paint. Your engine is nice so I'd be careful. If you hear the engine RPM race after spraying with starter fluid around the carb base you've got a leak. More things to try.
Im not familiar with your carb, but from the sounds of it, you've got an internal issue, a problem with the accelerator pump in the carb. Many carbs have an internal pump made up of a diaphragm of sorts designed to give a squirt of extra fuel when needed for acceleration. Might be someting to explore with yours.

DFitz

It does look like there is a gasket under the spacer. Many spacers are not glued. Just compression on both the top and bottom--fibrous spacers. An easy way to test the vacuum hole theory is just put a piece of blue masking tape over the hole and go out and drive it. See what happens. It also could be the spacer was put on backwards, now blocking some passages?

I'd also second the recommendation to get a vacuum gage. That'll tell you a lot.

There are also other possibilities, fairly simple. It may be that you aren't getting enough fuel volume at the higher speeds. Check the fuel filter in the bottom of the fuel pump. Also, you can try and remove and plug various vacuum lines to check integrity. Specifically the fuel pump. I recently had an issue where the diaphragm in the fuel pump was in the process of failing. It worked just enough for the engine to idle, but not get out of the driveway.

Weird things happen to these old cars, not always related to recent work, but I agree, something that was just done, and not a coincidence.

Tedd Thompson

Checking for vacuum leaks can be done as easy as spraying with W D 40 or use a propane torch(unlit) around suspect areas while the engine is running. They will show up right now if you have a leak.... Just a thought...Tedd

OLDSter Ralph

We are also assuming that the Edelbrock carb is jetted and calibrated for a 324.

Olds64

I'm surprised nobody mentioned the transmission kickdown linkage attached to the side of the carburetor. I'm not sure what transmission was in the 55 Oldsmobile but if it's anything like the Slim Jim Rotohydramatic that was in my 64 98 then it will NEVER shift correctly with an aftermarket carburetor. Do you have the OE 2GC or 4GC carburetor still? If so, you might want to go back to it.

FWIW, I tried to install an Edelbrock carburetor on my 64 98 and I couldn't get the transmission to shift properly. The early GM automatics use a manual linkage to the throttle valve. It's not as simple as attaching the TV lever to the carburetor linkage at idle with 0 slack. If you're a mechanical engineer with experience in early automatic transmissions you could probably figure it out, if not... good luck.

DFitz

All: remember it worked correctly before the sticky lifter work.....

Olds64

If that's the case then hopefully the OP can figure it out.

Andy

It definitely sounds like the trans is not kicking down in higher gears, A vacuum leak would be a problem throughout the rpm range..I bet it has something to do with the linkage to the kickdown on trans.

Tedd Thompson

I don't think so, you could check it out by manually pulling it down to third to see if it pulls better, that would be the same as having it kick down automatically till it reaches higher RPM. If it still is doggie, you are looking in the wrong place. My guess is that it is jetted to lean. What do the plug colors look like, white, brown, dark chocolate, black. Did you check your timing? You do know, first generation distributors do turn counter clock wise. Was the distributor removed when the lifter were replaced.. My guess is still that Edelbrock carb somehow. Rebuild the 4gc or at least stick it back on and run it to see if you gain something on the top end. It may not run well, but it may tell you what direction you need to go ...Tedd

Andy

You are missing the part where OP says it ran fine before with the same carb, jetting etc. its not the carb..timing, distributor possibly however op says it runs fine until it gets into upper gears.

Tedd Thompson

Yep, missed it, sorry...Tedd

Dave’s Holiday 55

Thanks for all the comments. The Edelbrock carb was on the car when I bought it. Everything worked fine up until the lifters and cam were replaced. I’m fairly certain the vacuum is not the problem but I’m willing to keep exploring that possibility. There is one black gasket like material between the carb spacer and the intake manifold. There are four of those same black gaskets between the spacer and the carb. See photos. Should there be a cork gasket in there somewhere? Picture 1 is as the carb sat in the car. Picture 2 is the spacer and gasket, intake side up. Picture 3 is spacer and four gaskets carb side up. The hole in the spacer referenced earlier does not go all the way through but I will put it back on with the hole facing the firewall, the way it was originally. Perhaps there is some blockage caused by its orientation as mentioned earlier. To Tedd’s point, when I manually downshift to “S”, it does accelerate normally. When I get it back together, I’ll mess with the downshift mechanism again. And I will enrich the mixture some. I also removed the vacuum line that went to the old wiper motor. It was plugged near the wiper motor but I will plug it at the carb incase that plug was leaking.

Picture 1

Picture 2

Picture 3

Tedd Thompson

Your wipers if original are run by the vacuum off the fuel pump and should not have anything to do with vacuum loss or carb settings. If the vacuum is ported or was ported somewhere else, this could be an issue. The vacuum from the fuel pump only runs the wipers and the windshield washers, nothing else. Just trying to find out what we are missing here... Tedd

Olds64

Those carburetor gaskets appear to be in good condition. You can reuse them, just make sure there are gaskets on both sides of that adapter plate. Also, you can get 1 thicker gasket instead of stacking multiple skinny ones.

Tedd Thompson

Just a guess, these are all just guesses, but youhaven't checked the cam to see if it was installed properly or is the correct cam(pain in the *** to check). That could be the problem and was done at the last of the build. I had a 394 that became a toad after a new cam was installed improperly, but it was a toad throughout the shift ranges, so the systems were different....Tedd

Olds64

I guess the way to tell if the cam was improperly installed is to remove the timing chain cover and look at the timing gears. If you go that far you MAW get a degree wheel and reinstall it.

Dave’s Holiday 55

Latest update. I got the carb re-installed today putting the spacer in the same orientation as it was before any repairs had begun. Enrichened the mixture one full turn. Made sure everything, vacuum lines, etc., was attached. It fired right up. Hot Damn! It’s fixed! Pulled out of the garage and drove down the street. Normal shifting and normal acceleration. After two blocks, the speed started decreasing as the engine RPMs slowed. Then it stopped. Would not restart. Walked back home, got some starter fluid, drove back to the ‘55, and sprayed in the fluid. With a little persuasion it started and I drove it home and parked it back in the garage. That is the second time I’ve had that experience. I’m beginning to think the fuel pump may be bad. Like it pumps up enough fuel to go a few blocks and then stops. I did notice moisture on the fuel pump itself on the ridge just above where the filter is mounted. It had been a couple of hours before I took this photo, and, as you can see, it is now dry, leading me to believe it was gas. Anybody see anything wrong here? And what is the dirty brass dome thing left of the fuel filter? And are those two brass fittings on top of the pump supposed to have something in them? They’ve been just like that while the car was running before all this started. My wife says I have to do the dishes for a month before I can buy a new fuel pump. Help!

Charlie Jones

Do you smell gas in that area after running?
If so, the fuel bowl may be leaking. There is a cork seal between the bowl and the pump that may be leaking.
The dirty brass dome is a pulse damper. It softens the pulses in the fuel pump outlet line. So as not to upset the needle and seat in the carb.
you should install a brass elbow between the pump and the damper so that it is pointing straight up, or at least a 45 degree angle.
The two brass fittings on the top are for the vacuum pump.
There are actually two pumps in this unit. The lower part pumps fuel. the upper part is a vacuum pump.
It boosts vacuum to the windshield wipers so that they work all the time.
One fitting would connect to the intake manifold. The other to the windshield wiper and or heater controls.
If you have electric wipers installed, they can be plugged.

Before you condemn the fuel pump, try replacing that metal fuel filter .
Also make sure you have the correct fuel tank cap. The tank may not be vented properly.

Dave’s Holiday 55

Thanks for the reply and suggestions. I have sensed a slight gas odor in the garage at times but not specifically in that area. I will be checking the sediment bowl soon. As mentioned above, after driving, I found the wetness on top of the lower part of the fuel pump. I don’t know where that could come from. What kind of fuel filter would be better than the kind in the picture? I think it probably has the correct gas cap because it had been running fine until this last “dying” symptom. I’m still wondering why it starts and runs well until I drive a few blocks before slowly dying, refusing to restart, then starting with starter fluid (after walking home and giving it time), and continuing to run until it’s back in the garage. It acts like it’s out of gas and everything slows down until it dies but there is no shaking, sputtering, or other indication of fuel starvation. I’ll reposition the damper as a precaution but has been working like it is. And I’ll plug the vacuum ports on the fuel pump just incase they may be causing a vacuum leak.

Charlie Jones

The metal filter is fine.
What I was suggesting, is that the filter should be changed out because it may be partially clogged.
It is a non-standard item for this car.
It was probably installed there to catch all the rust, dirt, and crap from that almost 70 year old fuel tank.

DFitz

I agree, it sounds like it is a fuel delivery problem. I had this exact same symptom a while ago. It took me 3 tries to get a fuel pump that worked. In the end, I rebuilt the pump I had. That worked.

There are several places that should be cleaned. On the bottom of the pump, there is a glass bowl. It may not look like it because it typically is covered in grime. Inside this glass bowl may be another fuel filter element. O' Reilly actually had the part, it's a Wix filter. The glass bowl goes on the bottom of the pump, in the pic it goes on the cork gasket. Under that cork gasket, is yet another brass screen. Then there is a screen on the inlet to the carb. Yes, I would replace the metal filter you have, any will do as long as it's large enough. I use a clear cartridge type so you can see if there is any contamination. If you see a bunch of contaminants in a short period, then it's time to clean the fuel tank and replace the screen sock on the fuel pickup.

Yes, that brass dome is an accumulator. As said, this softens the fuel pressure pulses from the cam action. It needs to be vertical. And yes, the 2 brass fittings on top are meant for the vacuum window wiper system.

Olds64

If you suspect a fuel delivery problem the easiest way to test that is to run the fuel OUT from the fuel pump into a gas can. Crank the car over and it should pump a solid stream of fuel.

Since you can drive your car to the end of the street crank the engine for a good 30 seconds to a minute (the longer the better) to verify the fuel pump doesn't give up. Make sure you have a battery charger handy to keep the battery healthy through all the cranking.

Tedd Thompson

What I do to for a easy check of a fuel pump is remove the fitting line from the carb, attach a Coke bottle to the line. Pull the coil wire off, so it won't start, crank the engine for about 10-15 seconds. This should put about 5-8 oz of fluid in your bottle. If it doesn't, you may have a problem with the pump. Some pumps will only be defective under pressure and this test won't show that, but most issues will show up with this test....Tedd

Dave’s Holiday 55

All great ideas!! I will be testing the fuel pump for sure. My mechanic says he has a gauge that tests both output pressure and vacuum. If these other ideas don’t work, that’ll be my next move. He says the fuel pump should put out 3 to 5 lbs. of pressure. Does that sound about right?

Olds64

3-5 psi seems low for an aftermarket Edelbrock carburetor. It might be fine for that mechanical fuel pump though. It was paired with the 4GC carburetor (predecessor to the Quadrajet) that came on your car originally.

Here's a good thread on fuel pressure:

https://classicoldsmobile.com/forums...ressure-53337/

Dave’s Holiday 55

Christmas company has come and gone, finally. I took the fuel pump completely out of the car, cleaned it up, cleaned the bowl ( it was not dirty, nor was the screen). I put it all back together with a new fuel filter. I bought a 90 degree elbow and reinstalled the compensator in a vertical position. I cut the old fuel filter in half. The paper filter inside was clean. It idled about ten minutes without incident. We’ve had a spell of nice weather, so today I took the ‘55 out for a test drive. I made it about two and a half blocks before everything slowed down and it finally died, just like it did before I had done anything I let it sit for awhile, it restarted (with starter fluid) and I drove it a block and a half back home into the garage. I had my wife (under mild protest) crank the car over, with the coil wire out, while I held a Dr Pepper bottle over the gas hose at the carburetor inlet. The fuel pump did pump but not in a stream. It pulsed a small amount out, brief pause, another squirt, pause, etc. I re-attached the gas line, it started and idled fine. So I think I can rule out a dirty fuel problem. I guess it could still be a fuel pump problem that doesn’t keep up when under pressure. I would take it back to the mechanic, but he’s more that two and a half blocks away. Any more ideas would be welcome.

Sugar Bear

Try running it on a separate fuel source e.g., a can of known to be good/fresh new gasoline hooked directly to the pump with a hose. Take all necessary steps to prevent a fire when doing this. If this works it's a supply issue to the pump, if it doesn't work it's the pump or in the carb if it is a fuel problem.

Good luck!!!

Dave’s Holiday 55

I’m still having trouble keeping the old girl running. After everything I’ve done (see earlier posts), the problem is still there. I started it right up yesterday with a few pumps on the gas peddle. It ran fine, maybe a little rough, then the RPMs slowed down and the engine went to sleep. No shaking, no backfires, just died. Then it would not start again. The same thing happened last week - started, ran awhile, went to sleep, wouldn’t re-start. If I were to go out there right now, I’ll bet it would start and run a few minutes and die. I’m beginning to think about the problem being electrical instead of a fuel issue. Does the coil work like a capacitor in that it stores up electricity to use as needed? It seems that after sitting a day or two, it will start, then die. Could the battery be charging the coil while the engine is off and then it be unable to hold that charge for a significant time? Could it be the generator? The gauge shows a positive charge rate while it’s running. Voltage regulator? Points and condenser are new. I would take it to the shop but it won’t run long enough to get it there. HELP!!!!

Tedd Thompson

Another wild *** guess, but remove the gas cap and leave it off for the start-up and run test. Sure sounds like a fuel issue and not electrical. Something may have plugged the vent between or during the build. In my time I have replaced more good coils than found bad ones, is it hot when it shuts down? It just doesn't act like a coil or condenser to me. As mentioned before add a stand-alone gas supply and eliminate the fuel delivery issue completely, If the generator is showing a charge and the battery is full that is all you can ask of it.
I feel you are about to throw parts at your problem but trust me that will only complicate the issues. We should have enough clues to figure this out....Tedd

Supernice88

Sorry you still haven't resolved your issue. I read through your whole post and see you still haven't tried what Sugar Bear and Tedd suggested. It does seem to be a fuel supply issue. Although it shows the fuel filter is clean it still might be in the tank. As suggested, hook up a fuel supply directly to the fuel pump inlet without the filter. If the engine stays running then it's probably the pick-up sock in the tank that keeps clogging up with sludge in the tank. The sludge gets drawn towards the sock when the pump is pulling and clogs up then when the fuel stops drawing the engine stops and then the sludge settles down until it gets drawn up again.

Dave’s Holiday 55

I’ll try that today. Not sure how I’ll get the fuel to the carb but I’ll figure something out.

Supernice88

Use a gas container, run a line in it to the inlet on the fuel pump.