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Discussion Starter #1
Today I briefly drove a '59 Alfa Two-Liter Roadster. Briefly because although it started right up and idled like a Swiss watch, it had little to no power. Honestly this has been an ongoing issue. I suspect the accelerator pump weights are stuck again or some remote passageways in the Webers are clogged up. I am tempted to revert back to the Solex PHH44's as they were no trouble.

About one or two years ago I found the brass jets all oxidized and green, due to ethanol :001_9898: All the jets were removed and cleaned and the Weber float bowls were filled up with Gumout or STP carb. cleaner and allowed to marinate for about a week, following a procedure found here on the ABB. It was better for a while but not back to normal.

It has good fuel, good spark, oil & coolant etc. just does not seem to advance under load. It revs "okay" without a load but still seems restricted. I could pull out the compression gauge and the timing light but I don't think the problem is either of those. Well I guess it could be stuck advance weights in the distributor. If the coil or capacitor had gone bad there would be weak or no spark, right? I put new NGK spark plugs in a month or three ago but they looked a bit sooty and wet; perhaps a critter has taken up residency in the air filter or something. Has anyone else experienced a similar issue or have suggestions of what to check?
Mark
 

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Mark,

Check the timing, and watch for the advance to kick in.

We will await your report.

Don

PS - I would expect that fouled Webers would have caused noticeable roughness. What are the odds of all four barrels getting gummed at the exact same time? Also, the accelerator pumps are most critical during acceleration, and at wide-open-throttle. Was your power loss during acceleration? I total loss of accelerator pumps might cause back firing through the intake.

D
 

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Discussion Starter #3
Thanks for your reply Don,
Check the timing, and watch for the advance to kick in. Will do as soon as possible...but it was fine when last checked maybe 250 miles (or several years:( ago.

...the accelerator pumps are most critical during acceleration, and at wide-open-throttle. Was your power loss during acceleration?
D
Yes, power loss was during (attempted) acceleration; if the throttle was pressed just ever so slightly it was okay. When pressed just a little farther, it would start 'bucking' until I backed off (quickly). It seemed to idle up hill better than accelerate...load is a problem. Down hill is not all that bad.

Mark
 

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Mark,

I agree with Don. There's an old saying, at least I heard it said a long time ago, but anyway, "90% of carburetor problems are electrical". I am not sure my experience bears that out, but putting a timing light on it and verifying the advance will quickly answer the timing question.

In situations like these, it is sometimes best to take a step back and verify everything. Check the condition of the points and condenser, assuming you have these. Maybe start fresh, including another set of plugs. Do a complete tune-up. You say gas is good. How old is it?

Check to see what might be living in your air cleaner. A short test drive without the element will identify that as a restriction.

Verify your fuel flow and pressure. You might also verify that one of your floats is not sticking. I know it doesn't sound reasonable, but Don experienced that problem and the engine ran smooth, but down on power. Bad ending.

More history might be helpful. Why and when did you trade out the trusty Solexes? Did the Webers ever perform correctly? When did the car last run normally and what has happened since?

Steve
 

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Now that you've added "bucking" during acceleration...

Vacuum leak
Insufficient fuel, which could be one or more accelerator pumps
Fuel pump, but you can probably rule this out if it supports high speed cruising
Bucking steers me away from advance mechanism
Points and/or condenser
Carbon tracked distributor cap
Rotor
Wires
Coil

Good luck
 

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Mark's original post seems to imply a flow restriction, and, as Don points out in post #5 above, this may not be limited to the carbs. So, what I would suggest -- long before considering switching carbs -- is checking the fuel supply system between the tank and the carbs in its entirety.

This includes checking the fuel filter in the tank, the filter in the fuel pump, the fuel filter in the engine compartment, the condition (and cleanliness) of the fuel lines. All of these components could be gummed up, filled with sediments or debris, having air bubbles that lead to vapour lock, etc.

It may be worthwhile to install a pressure meter before the carbs and observe how much pressure drops from idle to acceleration (see this thread about 106 fuel pump specs that I believe apply to 102 cars as well -- no matter whether measured at a fuel pump on a bench or in situ).
 

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the filter in the engine bay is not just a filter but a restrictor too. Just remove it from the system once, replace with an inline filter.
Do you have te tiny green plug cables? replace with better, copper cable. ( as you have points) No silicone cables etc.

Try using a jerrycan with fuel inside the car, hose to engine bay etc. To rule out tank debris etc.
Start eliminating stuff.
Oh, and JUST in case. Nord engines firing order 1342. 1900 and 2000 engines 1432...If I remember correctly...
 

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102 - 2000 engines firing order is 1243, but Mark would have very little power at all if this is messed up. I have tested this. ��
 
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Discussion Starter #9
Thanks for all of your help and suggestions! I sure have a long check list to go though but I suspect the accelerator pumps are stuck again or the Float valve balls could be stuck again. I have had both problems and did not think of the float valve balls since the car started up. Before when it would not start the float chambers were empty because the balls were stuck even though the floats were down in the empty well.

The 'real gas' in the car is only about 2-3 months old. It has run fine in the past with 'real gas' that was 2 years old or older. It will never see 'corn squeezins' again, I hope. I used the fuel pump to empty the tank of the old ethanol:001_9898: and it worked fine. I have since pumped about 5 gallons out of the tank in about 15-20 minutes, so around 15 - 20 GPH.

I changed to Webers because I feared the vacuum capsule failure and wanted more horses. Unfortunately I just made plans to go fishing tomorrow morning 3:30 am so it may be a little while...
Mark
 

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Mark,
I want to weigh in, too. Troubleshooting from a thousand miles away doesn't require much skill!
1. As from others, be sure you have full distributor advance. (Is this the time to add the Pertronix?)
2. Are the butterflies synchronized and opening fully?
3. The manifold de-siamizing was done properly, right? There is such a thing as too much fuel whirling around a common chamber.
Catch some fish!
Richard, with 01844
 

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Discussion Starter #11 (Edited)
Hi Richard,
Thanks for joining in! Today I was looking at S/N22 1844 in the 1991 Panoramic photographs taken at the Walter Mitty. I recall someone mentioning that you were in the photo somewhere but can't remember which car you were standing next to. Sorry, I feel like I am letting everyone down by heading to Lake Guntersville in the morning then Lake Allatoona...but 'I gots to'!

I have pretty much decided against using the Pertronix and will just keep the Roadster stock, the way it has been for 55 years. I will check the advance and make sure it is advancing.

Oh yea, I forgot to mention earlier that the Weber's were installed in or prior to 2001 and the car ran fine. Actually with the hood down the Webers were indistinguishable from the Solexs PHH44's and yes the manifold was de-siamesed by Robert P. who used to have a web site that showed how to cut slots and weld aluminum plates in the intake plenum. He also supplied the gender menders or adapters so the stock air plenum would mate up to the Webers. All nicely done but no significant gain in ponies.:frown2:

I need 'PC Anywhere' that allows a distant mechanic to work on a old car.

Tight lines,
Mark

Mark,
I want to weigh in, too. Troubleshooting from a thousand miles away doesn't require much skill!
1. As from others, be sure you have full distributor advance. (Is this the time to add the Pertronix?)
2. Are the butterflies synchronized and opening fully?
3. The manifold de-siamizing was done properly, right? There is such a thing as too much fuel whirling around a common chamber.
Catch some fish!
Richard, with 01844
 

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Just confirming the correct firing order as posted by Don; 1, 2, 4, 3.
 

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Hi Mark

I just mention this because we, well my mechanic, had a problem on the TI Super, one cylinder only, misfire, lack of power, poor running, after stripping the rear 45 weber for the nth time, he reverted to an exhaustive electrical check thru, found the coil intermittently defective.

Some truth in "90% of carb problems are electrical"

Good luck!

Richard
 

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low power fixed

I have just managed to replicate (unintentionally) and fix ( fortunately) a similar low power problem on my 2600 spider. It was simply bad plug leads and oiled plugs., I had been running for 500 miles on new carbs which weren’t correctly set-up. Starting got poorer and poorer and then the power went completely.

Changed to new plugs and an old heavy set of plug leads – I had been using the original Cavis plug leads which are rubbish and the car runs fine again.
 

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Discussion Starter #15 (Edited)
Changed to new plugs and an old heavy set of plug leads – I had been using the original Cavis plug leads which are rubbish and the car runs fine again.
The original plug leads (or OEM type just like in the parts book, not the 'rubbish green' plugs most parts houses sell as replacements) were still in the car when it came to me. I did have to replace one end that attached to a spark plug due to it having cracked phenolic material. Last year I realized the original plug wires were creating a 'light show' when I opened the hood after dark one night and saw the plug wires were arcing on the valve cover. Fortunately the original type black woven fabric material covered copper wire for the Two-Liter were still available through 'Deadbeat Customs' by special order on eBay (good only if you have the original ends). So the 'original spark plug wires' are like Grand pa's hammer; the heads been replaced once and the handle twice but it is still Grand pa's old hammer.

Tonight I checked the two items on the list that I most suspected; unfortunately the float valve balls were not stuck as there was fuel in both float chambers and the accelerator pumps were easily moved as well.:surprise:

Next, I'll check out the air filter housing in hopes that there is an obstruction, check the sparks ability to jump a gap and the timing advance. Oh the spark firing order is cast into the head of the Two-Liter right up front where it would be hard to miss but easy to ignore, I guess.
Mark
 

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"Bucking" can mean different thinks. In my experience, a rich miss makes noise, but not as much "bucking" as done a lean miss or a spark misfire. An obstruction in the air inlet side would generally lead to a rich condition.

Vacuum/inlet leaks
Distributor cap/rotor
Points/condenser
Wires.
Plugs

:)
 

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low on power list

Mark, to continue with posts #10 and #11 :

1) Check you have plenty of distributor advance.

2) Check cylinder compression. Throttle open. Factory psi? Don't know.

3) Yes, a coil can be bad. Swap in one from the Montreal.

4) Cheap shot: select a lower gear in the trans

In the '91 panoramic at the Mitty, I'm next to the GTA with the yellow front fender. What are the odds that 20 years later I would own the 2 liter that you brought to that event? Entirely possible! We're a small community.

Good luck. Richard

P.S. Note under the Forum "..other topics... I suggest that an Uber Alfa taxi service might be popular (and lucrative). Comments?
 

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Discussion Starter #18 (Edited)
I had a few minutes after work tonight to check out the Roadster; okay, I left early.
It seems that all of you in the 'timing camp' may be right. It took a while to figure out where to hook up the timing light and where to point it! I guess it was another senior moment but after a while I found a timing mark (PMS) and the pointer. With the rubber duct off between the air intake filter housing and the plenum, it seemed to run (or at least sound) better. The engine would rev up to between 2500 and 3000 RPM but the timing mark only moved a half inch or less...before the engine would cough and sputter. It backfired a few times and put out some black, fuel rich smoke. I plan to look into the timing closer tomorrow with my trusty "Glenn's - Alfa Romeo Repair and Tune-Up Guide" handy,,\

Glenn's Guide says "Late ignition timing causes overheating and loss of power. It can be detected by too smooth an idle, a deep sounding exhaust, a low vacuum gauge reading, and a lack of "ping" on acceleration."
We have Swiss watch smooth idle and lack of "ping" on acceleration.

Richard, your 1960 Two-Liter Tied for 'first in class' (I think) at the 1991 Walter Mitty with the blue AutoDelta Montreal (ex John Murphy), that now belongs to Ward W. Delmas G. and I both have the stock twins to this car.
Mark
 

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Discussion Starter #19
Definitely possessing more tools than talent!

With the rotor button removed it was possible to gently manipulate one advance weight. The engine could be rotated to expose the other advance weight which was also easily manipulated. It would freely move 'out' and spring back 'in' or the four lobed shaft could be gently twisted causing the weights to go out and return under spring tension. The 15 year old condenser was replaced with a new one; to go with the new rotor and distributor cap and the points were cleaned with 400 grit wet or dry sand paper. The engine started right up, the timing at idle was spot on and the engine revved right up to what sounded like about 4,500 rpm (I could not see the timing marks, the Sears Engine Analyzer 'tach' perched up on the tool box, twist the distributor and hold the timing light all at once). The next thing I knew the engine just seemed to loose power gradually and return to idle as I tried in vein to give it more gas.:confused:

Undeterred, Grand pa's original spark plug wires were replaced with a set borrowed from the Duetto The engine started right up, the timing at idle was spot on and the engine revved up some but sputtered and popped so back we went to Grand pa's original plug wires (with one new head and all new copper wires). :confused:

This time the Duetto donated it's coil to the cause, so with high hopes, a borrowed coil, clean points, a new condenser, new cap and rotor, basically new plug wires and loose advance weights; just as I saw 5000 RPM, the 'AM' mark lined up with the pointer and thought "I got it" the engine sputtered once or twice, backfired through the carbs or tail pipe(?) and just stopped, again. So after 6 hours of trying, Blue Baby was pushed back into the garage because it would not start again- even with a jumper battery.:crying2:
I still blame the darn ethanol:001_9898:

Hopefully the fuel pump will check out tomorrow any other suggestions?
Mark
 

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It can be significant if the backfire was through the intake or exhaust. If the intake, I might guess a failing pump or other fuel line restriction that is causing the float bowls to go low after just a bit of running.
 
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