Running Rich Or...?

E-Type
1

Asking for a friend. No seriously. My buddy down the street has a 66 OTS that he recently did a full engine and drive train restoration on. I’ve been helping for laughs and giggles, all this past spring and summer. The car is stunning.

This is running on stock distributer, points, condenser, etc., with triple SUs, naturally. The carbs and distributer were sent to a couple of the recommended big boys for full R&R.

Shortly after we got it running, we checked the points, timing etc., and tuned the carbs by the book. The car has been running fine all summer, and only has 100 miles on it.

Suddenly, there is a hesitation on acceleration. It does not happen when the car is stationary, ie, blipping the throttle in the garage. We checked the timing again at 10 degrees BTDC, and it was spot on. We checked the distributer wires by attaching the timing light to each high tension lead in succession and found #2 was spotty (he did not change the leads in the resto). We tightened it up, went for a test run, and the problem was still there.

We pulled the plugs and they were extremely fouled, indicating way too rich. And yet, the exhaust note is extremely stable and we’re getting no blue smoke.

So the question is, how can the carbs “suddenly” be running very rich after only 100 miles? We’re ready to tear into them, but it just doesn’t seem right to me.

In searching the JL site, possible culprits for the lope are:

  1. Timing
  2. SP/Distributor wires
  3. Carbs
  4. Faulty condenser

Item 3 can cause the lope via rich running. But, again, at idle the exhaust note seems perfect.

How about item 4, the condenser? If so, by logical deduction, does this sound like a bad (new) condenser? My buddy doesn’t think so. He wants to change the wires and retune the carbs.

Any insight?

2

I can’t see how the condenser is going to foul your plugs. Clean the plugs and see if it goes away for a little while. If so that points you to mixture.

3

Th stock UM carb needles are too lean for E10. I bet your rebuilder swapped in a needle that’s too rich. I use UX needles, others have had luck with UB. Pull out a needle, and the identifying letters will be stamped near the root. Let us know what you’re running.

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4

Hesitation on acceleration under load may be due to lean mixture for conditions. A car that has been driven only 100 miles over the entire summer may not have had circumstances where engine was warmed up fully. A cool engine run without sufficient enrichment while cool will hesitate on acceleration under load. The general carb setup aims for car running when warmed up fully. Enrichment above the general carb setup is used for when engine is cool and does not vaporize the fuel as thoroughly as when warm. A stumble on acceleration under load also may be due to timing curve advance not correct. Both of these possibilities are more subtle to detect without engine under load.

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5

Your observation that the hesitation on acceleration is sudden in its appearance could be related to change in weather. If all the 100 miles were done on warm summer days, the car would have been warmer from the start. Colder weather means the car and fuel are colder at start and a greater enrichment at start, and for longer time used, could mean the hesitation is experienced now while it was not long present during summer excursions.

6

Thanks, we’ll have the carbs apart and check the needles. That said, he’s running non-ethanol with a sip of leaded racing fuel.

7

We fully warmed the engine to normal running temp. Also, it wasn’t a particularly cold day. We were in shirtsleeves.

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8

…and Joe Curto did the carbs. Man, they look beautiful, all new and shiny with new fasteners.

9

Ok I’ve had a similar problem here…. Check needle length they need to br exactly all equal as in to 2 decimal places…… if you have differing rates of travel as the carbies open up it maybe that a lack of fuel is getting to one carb causing a hesitation…. This is especially on acceleration from idle to 1800 rpm as this is wher the needles do most of the work on fuel flow.

The fouling of the plugs could be due to prolonged use of the choke….use the minimum choke to start and idle the car …reduce to no choke ASAP ……give it time to warm up …… I usually don’t drive mine until I see a movement in the temp gauge
….
If it were me get the car to normal running temperature ,I’d clean the plugs, turn each fuel mixture leaner ( anti clock) by half a turn ….go for a good run …… rinse and repeat until plugs are clean with no soot

I’d also run hotter plugs …I use 6 ers

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10

Not to add two cents but Tom said the car was running fine?
Then after 100 miles started breaking up or hesitating
Pop the distributor cap and swap out the condenser
It takes 5 seconds
I bet your done minus cleaning the plugs at high revs😀
Report back
Repro stock condensers are junk along with the rest under the cap IMHO
Once the condenser is swapped and it runs fine
Along with checking the ground and coil
Report back
I have a better solution
Funny NOW E10!is no good with stock needles?
I thought the gas was fine :crazy_face::crazy_face::crazy_face:
Report back
Gtjoey

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11

Yes, it had run perfectly. Are you saying a bad condenser can foul the plugs? I’ve got an NOS one laying around. Wouldn’t be hard to swap it out and give it a whirl.

12

Go. Go. Go
Check your base plate and make sure the little ground wire is tight as well
Gooooo
Gtjoey

13

So once again, as the thread heads towards the phone call and the 123 pitch. Ethanol has a higher oxygen content than gasoline, so it needs to run richer,. 14:1 vs 14:7 for straight gas at sea level. The currently available needles…all of them…are too rich. I would guess that you’ve been given a UE needle or richer.

I would suggest that fouled plugs are far more likely than a bad condenser, but try it and see.

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14

Two or Three years ago when I posted my 66 red Etype and poured in a couple of cans of VP non ethanol , which I do in all my stored for winter classics
All the old farts said…….
It’s a waste
There’s no difference
There’s no science to prove different
Well as time goes by Joey dumbass was right again
And again
And again
Even Wiggles has seen the light and science!
I never mentioned the 1-2-3 at all
But again as Jaguar Heritage, Eagle , Donovan’s , Terry’s and all the rest use 1-2-3
If it is the condenser or the 55 year old distributor
What do all the above do?
Like Joey dumbass put in a 1-2-3 and drives thousands and thousands and thousands of miles
Your grumpy lately Mike , go for a drive in the fresh air across the Theogs Neck Bridge let’s do lunch❤️

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15

Cheeses K. Reist. Let’s get off the ethanol thing. As mentioned, this car is running on ethanol-free gas, easily available in my area.

@Michael_Frank, which needles are appropriate with non ethanol fuel?

Note, we cleaned the fouled plugs and a short drive around the block fouled them again. We’re talking mere minutes.

I have a hard time believing a set of Joe Curto’s SU rebuilds that were functioning perfectly could suddenly be running rich and fouling plugs and causing a lope on acceleration. Also, remember at idle, the exhaust note is perfect out of both pipes. Tuning by the book…

So, can it be a faulty condenser, yes/no?

16

Stock needles…and
Yes, Try it tomorrow, if its the condensor its a 2 minute fix…
Then Ill call you at home and twist your arm to BUY a 1-2-3 distributor . :rofl:
We do understand I have nothing to do with the company…But its like Jesus telling the Oxen and Ass to go to the well…If they dont drink? WELLLLLLL :grinning:
p.s. what spark plug wires are you using Copper core or Carbon? Just another thought.

17

A condenser can cause many “strange” issues, mostly centered around a miss. Not sure about a lope. Doesn’t really sound like one, but give it a try.
Tom

19

image
image1920×2560 456 KB

Can you read this one?
Read the purple highlights

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20

Nobody has asked what oil he has in the pots?

21

The standard UM needles should work for non-ethanol gas. Check the needles that were installed in the carbs. It’s probably a perfect rebuild, but he may have anticipated the use of E10. If they are UE, UB, UO or UX, and you are using straight gas, try going back to UM and that should fix your fouling problem. All of these needles are identical at idle. If the needle is right, the tune will hold throughout the rev range, if the needle is wrong, then the engine will become either rich or lean whenever you’re above idle.

If the spark plugs had been fouled, replace them rather than cleaning them. They’ll continue to soot up until the overrich condition is resolved.

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