If I press down more than 1/4 throttle engine stumbles and shuts off

Something like this?

https://shop.advanceautoparts.com/p/mr-gasket-fuel-regulator-9710/6340000-P?searchTerm=universal+fuel+pressure+regulator

The Medic

I think this is it... I'll have to check mine to verify the pressure range, but it seems right. Initial setting was the 6psi,I mentioned before. (Either way it looks and connects the same.)

https://shop.advanceautoparts.com/p/holley-fuel-pressure-regulator-12-803/17120441-P?searchTerm=Holley+fuel+regulator

The Teflon tape or Teflon paste will work for the fittings.

Are you still using the original type fuel filter which has 3 connections, one being the return line to the fuel tank?

The Medic

Good deal, just finished reinstalling the regulator with Teflon at the fittings. Wasn't sure it'd hold up to the fuel

No, I haven't got the 3 port filter or return line installed.. had some issues removing the fuel tank to install the new return.
He'll eventually have the factory setup again.

Took a little 15 second video of the stumble. Going to try to figure out what it takes to upload to YouTube. Once I do, I'll post a link to it for ya.

Let's see if this works.

https://youtu.be/rGrExHFPP8g

You don't have to upload to YouTube, you just upload directly to this site. Could you do that again without the air cleaner on, want to see what the secondaries are doing as the throttle opens, also open it a bit slower please.

I'll get one this evening. Kinda doubt my neighbors want to hear me racking the pipes at 7:00 am. Lol

Oh and to add to it, while you are testing, get a can of carburetor cleaner and as you rev the engine and it starts to die off, spray some into the carburetor, if it suddenly wakes up and runs better, you know it's starving for fuel.

That seems so obvious that I'm wondering why I haven't already done it! Hahaha
Thanks bud

Good call on the carburetor cleaner while accelerating, Steve W.
I have 2 videos. 1 with slow acceleration to stumble the other I think I accelerated a little too quickly, but it does include carburetor cleaner with an improvement. I'm hoping you're able to see the butterflies in both videos.

Let me know if you can't and need a better view or anything.

Is Mr. Regulator directional? (arrows?)

Sounds fuelish.

Running the proper pressure?

Maybe too much pressure?

Bowl level is correct?

Mix screws are correct?

Maybe the jets are too big for the 258 (I'm running 52s-soon to be 51s soon!

Has it ever run well with this carburetor?

The Medic

It looks like the secondaries are not adding any fuel? Cannot tell for sure but I can see the accelerator pump squirt on the primaries, and fuel spray there. The other side looks dry. Do you see fuel on the other side?

Medic, from his earlier posts it seems it hasn't run with this set up for at least two owners.

CJ MEDEVAC

Regulator is directional (in through bottom abd an outlet either side)

Fuel pressure is at 6psi and my gauge was leaking fuel a little. (Very little) Carburetor had the same reaction with 10psi unregulated.

Have not had a chance to double check bowl level. However, I believe I had them set correctly

Mix screws are each out 1.25 turns from seated

Jets are the stock 57s (I thought about testing with smaller, maybe the 52s you're running???)

I bought the jeep with this carburetor thinking it was going to be a simple mixture screw adjustment issue and ended up here when it wasn't

Steve W

From what I've heard from Holley. The vacuum secondaries will only engage under a load and will not be visible "in the driveway" (No, I haven't seen fuel in the secondaries.)
From what I've noticed this stumble is preventing the engine from pulling enough load to open the secondaries while going down the road. I'm now thinking I need to try the "paperclip test" to see if the secondaries are opening.

both of y'all
Can you see my frustration? Lol
I will happily retest anything I've tried and any/all new tests y'all have. I want him on the road!
Thanks again

That picture was meant for my last answer.

I don't think the vacuum secondaries can kick in with the vacuum being high.

I think his is like mine, no squirters on the secondary side, I feel sure the other end will be dry until it's on the road under load.

The Medic

No squirter on the secondary side (single pumper not double) there are jets. The jets are stock on both sides at 57.

This carb wants 7psi at idle (optimal per Holley specs) I'm 1psi low right now
I think it wants 4.5psi to run & can't remember off hand how many gpms it wants

Edit: I'll try to get a pic of my regulator and filter setup in the morning (still only have the 2 port filter installed.)

Try reaching in there with a tool and opening the secondaries as it stumbles. If it starts running better it shows a definite lack of fuel. Pressure wise I don't think you need to worry yet, The higher pressure just ensures the bowls are kept full under higher flow, at the moment you cannot get that engine to run hard enough for that to be an issue.
I'm wondering if a tear down and trip through an ultrasonic cleaner would help. It sure acts like a fuel issue. How old is the fuel in the system and is it pure gas or ethanol?

I've manually opened the secondaries as it stumbled and, yes, it picked up and ran/sounded great.

I was just sitting here wondering; if my jets are too big and my vacuum is a lot higher than Holley expected... could my vacuum be sucking all the fuel outta the primary bowl?

Here's why I'm thinking that; stock power valve is 2.5... makes me think Holley built it for about 6 in hg. Whereas I have nearly 20 at idle (full manifold vacuum) I've tried the 10.5pv but still had the 57 jets.

It seems to me that I should be running a smaller jets (maybe the 52) with something like a 10.5 or 11.5 power valve.

Am I way off track or does any of this seem logical?

Edit: forgot to answer your fuel question... it is ethanol gas, less than a week old. Been started everyday up to operating temp too

That's one of the things I'm wondering if the engine needs more flow. Perhaps a bit of power valve and spring changes to get the secondaries to tip in earlier?

I've got a vacuum spring set. I'll install the lightest and change to the 10.5 pv tonight.
It'll have to be after dinner with my daughter thi, so a bit later than usual. (Probably around 730-8 Central time)
Cross your fingers for me!

I don't think messing with the secondaries is going to solve the problem with the primary circuit.

Holley has this selector thingee.

https://www.holley.com/retailer/carbselector/

You might call their support number and tell them what you have, see if they can help with the jetting.

The Medic

Installed the 52 jets and 10.5pv... no change.
Gonna try to drop the tank so I can get the return line and 3 port filter installed.
With my regulator having 2 outputs should I keep one plugged and setup like on Mr. Jeep (regulator on return line), should I install the regulator before the filter, or use the 2 port filter before the regulator with 1 output to the carb and the other to the return?

I know, too many options... I'm thinking I'll start with the setup like Mr. Jeep and regulate the pressure in the return side.

I'm all ears gentlemen

I think I'd stay with the latest Mr. Jeep pic I sent.

Regulator on the return line, Gauge on the carburetor feed line.

This will let you see and adjust the actual pressure to the carburetor.

(Before, the regulator was before the filter, I finally realized with the "open" return line the pressure/ volume was being bled off and could only build pressure to a certain point.

This better way, regulator on the return, still allows fuel to return to the tank, not over-powering the needle and seat. It now allows better pressure and volume to the carburetor. It's sort of like squeezing the return line with pliers to increase everything before.)

Sorry, I'm still learning as I go too!

One other option

I gave $100 for sick "Willy" back in 1991

I'm willing to go $150 if you get desperate! Lol!

The Medic

Who says I'd need to be desperate to buy an old Willys? Lol.
That much of a project would keep me busy for a LONG time!
Is that a pic of willy when you first got him or is that a different one?

& that meme is hilarious! People whine too much nowadays.

Unfortunately, didn't get anything done on Carl today. I'll post as soon as I do.

My wife sent these to me recently. Thought I'd share.

I really liked your 1st meme, I reckon I'm maybe to old to understand the other one.

Yep, that was Willy, here's a few more.

Unfortunately, back then pictures required developing or were VHS (in this case).

I wasn't much of a picture taker, but my buddy had a cam corder and that was high tech in '91!

A while back, another friend converted my few VHS tapes to digital and I was able to make some screen shots.

This was shots from "My" day 1 with Willy till he was street legal again two years later. All within a one car garage on my side of the duplex I was renting. Next to the last pic is my four year old little girl who helped all along. Last pic, she's now 32 and Willy is 73.

No sense in yours sitting idle, you need to jump on it! For two long years I longed to drive my own Willys Jeep.

The Medic

Just had a coworker suggests converting my distributor to a points and condenser type... pro's? Cons?

Fyi: I don't own a dwell meter or possibly other tools for that setup, so I'm rather hesitant to go that route. Still thought I'd throw it out here&get other thoughts on it

Electronic is a lot better that points. Hotter spark, better control and less messing around as they don't wear like points.

I concur!

Stay OEM

Everybody wants you to convert to something totally odd and hard to work on. On a Jeep, there's really no more betterment in changing stuff, just more confusing to hook up and use. I suggest leaving the distributor and ignition system alone. Unless you want to make a backup system to use after the ICBMs stop falling and the EMPs have destroyed all electronics. A point system could be installed fast and be usable.

A dwell/ tach is a really good tool, I like it better than using a vacuum gauge to tune the carburetor. A plain Jane non-adjustable timing light works well too.

I see them cheap in pawn shops now days.

The Medic

You guys definitely confirmed what I was thinking.

As far as tools. I have an adjustable timing light (not a fan, using my father in laws normal one). Vacuum gauge and tachometer... I mount it under hood when needed, later I'll install inside the cab, cause I tend to watch rpm's while driving.

Thanks again... sorry no updates on Carl yet

IF y'all are interested... here's Beatrice "Trixie" my wife's TJ. Picked her up for a steal because she needs a lil work on the frame (2 weld-on patches @ $150 each) otherwise, runs and drives great...

Always game to see a "real" Jeep.

"Real", to me, does not include the station wagons types!

Looks good!

I still prefer carburetion.

Jump on Carl, he needs to be on the road!

The Medic

Or go real old school...

Guys, I finally had a little time to work on Carl... in the meantime I've been reading anything I can on tuning Holley carbs.

To keep this under 5000 words... once I got home today I changed out the pump cam. First I tried the blue, then the brown. Gotta say, MAJOR improvements! Actually got to drive him down the road today & made it up to 50 fairly quickly.

From what I was reading, looks like I still need to get a much smaller shooter (pump nozzle) to extend my pump shot a little longer.

Can't say how excited I am that something improved the way he runs the way I was expecting it to... especially after so many attempts and misses.

Btw, I wish I had some of those tools. I absolutely love old tools (they don't make then like they used to)
My collection is primarily somewhat cheap automotive tools, and basic stuff. And recently I've been building up tools for my woodshop. Mostly "craigslist" tools that I can afford when I need them, with a few new tools of varying quality.
However, I picked up a skilsaw that's absolutely a beast.

Anyway, I'm gonna grab a drink and relax a while. But I wanted to share the success with you guys, cause I'd already have him at a mechanic if it wasn't for y'all.
Maybe not be quick results, but it's much more satisfying this way.

Great to hear. I prefer a lot of the older tools myself, back when they were built to be repaired instead of replaced.

Well gentlemen, it's time for an update.

It seems that I was not properly setting my timing. Specifically my vacuum advance... I might not have understood there was an adjustment for that. (It's okay to laugh, I laughed at myself)
Once i learned of my mistake, i spent a few minutes adjusting and voila! He's not falling at his face every time I open up the throttle.

I still need to finish the fuel system rebuild (replaced everything except the tank and carburetor) and get things properly bolted down, verify idle and total timing, hit the road for a test drive, and make any necessary adjustments. After that, I've got him road ready!

Turns out I could've fixed the problem before I drove him home! Live and learn, am I right?

You guys are awesome and I can't thank you enough for everything I learned from y'all.

I'll still be here from time to time... might even share some advice I've received via this thread.

Have a great one, and happy Jeeping.


Last thing. Saw a quote the other day. It said basically: if you want to know if you're a Jeeper, buy an old CJ, spend months sourcing parts, bleed, sweat, maybe even cry, trying to restore it then drive and enjoy... otherwise, just buy a wrangler.

Thanks again, gentlemen.
Jeff
86 cj7: Carl "the scarecrow" (if I only had a brain) lol

It's about time!

We thought your GPS took you somewhere else!

Glad to see you returned to the world of Jeeping!

Just a thought, I've answered bunches of CJs, and a lot of other vehicles too. As far as the CJs go, you might Google search 2carpros, cj medevac, Jeep and then hit "images". You might find something that interests you. All of the stuff is not mine, but quite a bit is.

Well my pictures did not win either the front or back cover of the recent Willys parts catalog contest. :-(

These were some I did/ or was going to send in.

Send us an action shot of yours!

The Medic

Great to hear you've had some success.
Around here the CJs don't survive the salt and winter. These days many are buying the Cherokees and making them into off road beasts. They hack the fenders open, add in sheet metal to close the holes and lift them up 6" or more.