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1968 Jeep CJ 225 Dauntless V6 Dies After Warming Up


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New to the Jeep family and picked up a '68 CJ5 Willys Overland. Needs a little work. 225 dauntless odd fire, SM 420 4-spd,  Model 20 Spicer transfer case, Saturn overdrive, Dana 44 Jeep Wagoneer axles, 538 gears and Warren hubs. Current issue is that after it warms up, it stalls out. Sit for a few minutes and you can start back up and go another 1/4 mile or so before repeating the issue. A couple of thoughts that may be causing this.... mechanical fuel pump going bad, coil collapsing, distributor issue?? It does have the Rochester 2 jet, single barrel carburetor on with stock manifod.

Thanks in advance for feedback.

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B Rad...Let's consider some possibilities based on what you've shared.  See my comments/reply in red:

5 hours ago, B Rad said:

New to the Jeep family and picked up a '68 CJ5 Willys Overland. Needs a little work. 225 dauntless odd fire, SM 420 4-spd,  Model 20 Spicer transfer case, Saturn overdrive, Dana 44 Jeep Wagoneer axles, 538 gears and Warren hubs. Current issue is that after it warms up, it stalls out. Sit for a few minutes and you can start back up and go another 1/4 mile or so before repeating the issue.

Sounds like a possible fuel supply or coil issue...Check both the fuel pressure and volume at the line from the pump to carburetor.  You not only need pressure, you also need fuel volume.  Symptom sounds like a vapor lock possibility.  Check the fuel line routing near headers, hot intake, etc...Electric or mechanical (stock) fuel pump?

See whether the coil has a ballast resistor.  Straight 12 volts to the coil will overheat it.  You're on the right track, coils fail when hot.  A bad or missing ballast resistor can create the same condition.

A couple of thoughts that may be causing this.... mechanical fuel pump going bad, coil collapsing, distributor issue?? It does have the Rochester 2 jet, single barrel carburetor on with stock manifold.

If the engine runs well when it does start, that somewhat rules out the distributor other than a bad condenser.  If still a breaker point ignition, the 225 Prestolite distributors are notorious for bad shaft bushings that throw off the breaker point dwell angle.  That would not be an intermittent problem, but a Delco distributor was always the solution.  Aftermarket distributors are also popular.  If the distributor has a Pertronix conversion from breaker points, that could be causing the symptoms you describe.

Separate the issues:  fuel versus spark.  Systematically eliminate possibilities like a clogged fuel pickup, restricted fuel flow, bad fuel pump diaphragm from setting for a long time, a bad gas cap, a short fuel pump stroke from a bad fuel pump eccentric, etc., etc.

The 2GC Rochester, if in good condition, should be okay.  It could have a sticking float needle that's starving the float bowl for fuel.  Symptom would be somewhat like vapor lock.  The two-barrel 2GC is a good carburetor for easy service and tuning.  It may need both.

See if any of these factors are at play, we'll go from there...How long did this vehicle park without running?  Rust and scale in the fuel tank?

A few details to help orient you to your "new" Jeep:  1)  the Rochester is a two-barrel carburetor, and 2) if you have a Saturn Overdrive, the transfer case is a Spicer Model 18 not 20.  The Saturn fits into the rear facing PTO access of the Model 18.  The transfer case should be a side drive with both driveshafts outputting from the dropped portion of the transfer case. 

Do your front and rear retrofit axles have offset differentials that align with the transfer case outputs?  (I see that the front does.)  The rear axle could be a stock '68 CJ rear axle with the offset differential.  However, that would be a narrower track width than a stock Wagoneer 44.  Some photos could clarify what you have here.

The Spicer 20 (1972-79 CJs) has a direct output to the rear driveshaft that's on the same plane as the transmission's output shaft.  The front driveline's output would be a side drop.

Moses

Thanks in advance for feedback.

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Thanks for the response, Moses. I believe this Jeep has had a great deal of mods done to it. I will take a look at the fuel line placement, as they have rubber running up from the mechanical fuel pump vs steel with fittings, and I know it's right near, if not tight to, the front of the block.

I'll take a look at the coil as well...I'm not recalling a blast resister, but that may be remote located as well I believe. The coil itself is mounted directly to the front of the engine block as I recall.

The fuel tank has been upgraded to poly and is located at the rear under the bed. The filler neck has been relocated to the passenger side, rear. I will see about getting a new cap, just to rule that out as well.

After looking at these issues, if no success, I will pull the carb and check out the float to see if all is working proper.

I did replace the plugs last night, albeit, they were unremarkable. I've not pulled the distributor cap off yet. I've been thinking of upgrading to an electronic/HEI distributor/system, just to eliminate issues from that direction.

I will follow up with additional photos and info when I get back to the shed later today.

Thanks again, greatly appreciated!

Brad

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Brad...You're taking a thoughtful, appropriate view of these needs.  I'm glad to be a sounding board and field your questions.  Your CJ originally had a ballast resistor, sounds like you know what that looks like, here's an image just in case:

https://www.quadratec.com/p/crown-automotive/ignition-coil-ballast-resistor-jeep-cj-5-cj-6-and-sj-j-series-6

The HEI distributor would be useful for the ignition system.  HEI operates directly on 12VDC current and is certainly as reliable as breaker points, etc., with far better spark delivery.  Keep in mind that you have the odd-firing engine when picking a distributor.  Curious which distributor your engine currently has:  Delco or Prestolite.  Photos when you have time...

Moses

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  • Moses Ludel changed the title to 1968 Jeep CJ 225 Dauntless V6 Dies After Warming Up

Hello, Moses. I found a couple of thing that may be contributing to the problem. 

- First, the balast resister is present on the fire wall, but had been removed from the circuit.

   > I will be wiring this back in/replacing the balast resistor.

- Next, the coil is mounted tight to the front of the engine block.

   > I will need to fab up/find the proper coil mount to get the coil off of the engine surface.

- Finally, the gas line is zip tied to the front of the coil, with ample space around it other than where it is tied to the coil.

   > Considering options and leaning towards replacing the rubber hose with a proper steel line from the fuel pump to the carburetor.

Not knowing how long the Jeep had sat prior to us looking at and driving/riding in it, I decided to throw some Seafoam in the gas tank. I put a couple of Mike's on it, having one instance of it stalling again. This past evening, I started it up and let it idle a bit. I had a 9 mile drive to go in to a fund raiser with our Jeep Club, and the ride back home. Prior to leaving, I grabbed my dead blow mallet and tapped the carburetor, hoping to dislodge the float if it were sticking.

I made it all the way into town, had dinner with the Club and drove home with no trouble. One additional factor is that the outside temperature was also down apx 10-12°. This along with the Seafoam and tapping beith the dead blow, are the only actual things having been done so far.

I have attached a few more pictures for your review as well. The underbody shot is not the best, but does show that the rear differential is offset to the right to align with the transfer case.

Thanks again...I will follow up with more as I work through the list! Have a great rest of the week and Labor Day weekend.

Sincerely,

Brad

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B Rad...Photos help.  See my comments in red below...

On 9/1/2021 at 2:24 AM, B Rad said:

Hello, Moses. I found a couple of thing that may be contributing to the problem. 

- First, the balast resister is present on the fire wall, but had been removed from the circuit.

Running straight 12V to the coil without the ballast resistor is a good way to burn up a stock coil.

   > I will be wiring this back in/replacing the balast resistor.

- Next, the coil is mounted tight to the front of the engine block.

One common coil mount location was on the intake manifold of the earliest Buick 90-degree V6s.  The engine-to-coil (shell) ground is important.  See the coil on the intake manifold of this stock Buick car (not Jeep CJ) 225 V6.  The two-barrel carburetor likely relocated the coil to the front of the cylinder head.  Your coil is currently in one of the stock Jeep CJ V6 positions.  The coil bracket isolates engine heat, and the coil makes plenty of its own heat.  Do an Ohms-resistance check on that coil both cold and hot...

buick_dauntless_v6

   > I will need to fab up/find the proper coil mount to get the coil off of the engine surface.

- Finally, the gas line is zip tied to the front of the coil, with ample space around it other than where it is tied to the coil.

Personally, I would restore the OEM steel tubing with preformed brake/fuel, double-flared tubing.  Make suitable, good looking bends with a quality tubing bender.  If you run an inline filter, find one that accepts flare nuts at each end.  I don't horse around with rubber hose at the fuel filter, that's a fire hazard.  (If you do attach rubber to steel pipe, be sure to make a bubble flare at the tubing end to keep the hose from blowing off.)  I make a metal support bracket for the tubing that reduces the risk of vibration.  The intake manifold or coil mount threads are a good place to attach the support bracket.

   > Considering options and leaning towards replacing the rubber hose with a proper steel line from the fuel pump to the carburetor.

Not knowing how long the Jeep had sat prior to us looking at and driving/riding in it, I decided to throw some Seafoam in the gas tank. I put a couple of Mike's on it, having one instance of it stalling again. This past evening, I started it up and let it idle a bit. I had a 9 mile drive to go in to a fund raiser with our Jeep Club, and the ride back home. Prior to leaving, I grabbed my dead blow mallet and tapped the carburetor, hoping to dislodge the float if it were sticking.

I made it all the way into town, had dinner with the Club and drove home with no trouble. One additional factor is that the outside temperature was also down apx 10-12°. This along with the Seafoam and tapping beith the dead blow, are the only actual things having been done so far.

Sounds like a sticking needle and float, which may free up—or maybe a vapor lock when the ambient temp rises.  The Sea Foam helps with the needle and seat.

I have attached a few more pictures for your review as well. The underbody shot is not the best, but does show that the rear differential is offset to the right to align with the transfer case.

Thanks again...I will follow up with more as I work through the list! Have a great rest of the week and Labor Day weekend.

Sincerely,

Brad

See my comments below, Brad...

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Looks wide (like Wagoneer) but is offset.  The axles came from a seventies Jeep SJ or J-truck model equipped with a Borg-Warner Quadratrac transfer case (used with the THM400 automatic transmission in '76-'79 CJs).  These transfer cases, used through 1979, have an offset, dropped output for the front and rear axles' differentials.  This gets confused with earlier Model 18 transfer case axles, but you can see that your axles are wide track and an open knuckle at the front.  My guess is a J10 pickup, Wagoneer (as you note) or full-size Cherokee application.  Good stuff axle wise.  The Quadratrac was "okay", a chain drive transfer case often converted to have a true part-time 2WD mode for use with front axle free-wheeling hubs.  You have the Spicer Model 18 transfer case, noted by the Saturn (Warn-type) Overdrive that we can't see, but you share is there.  Here are the models that used the Quadratrac transfer case.  The SJs and J-trucks use a 44 front axle, the CJ uses a Dana 30.  Some models use an AMC 20 rear axle, your donor vehicle obviously had the Dana 44.  You should have factory disc front brakes if a 1974-up application.  These models had the Quadratrac/automatic transmission option:

1973-1979 Jeep Wagoneer (SJ)
1973-1979 Jeep Cherokee (SJ)
1973-1979 Jeep Gladiator
1976-1979 Jeep CJ-7 [would not have a 44 front or rear axle]

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You have the Delco-Remy, much preferred distributor with the "window cap".  If the shaft bushings are okay, this is a "keeper" distributor.  You can run it with breaker points and condenser or a Pertronix electronic module conversion.  Either works.  If you use the Pertronix, have a spare unit or a set of points and condenser in your off-road kit.  The Delco-Remy distributor (Buick style) is an easy distributor to service and re-curve, including the vacuum and centrifugal advance.

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Yep, it's a Dauntless V6, the classic nailhead Buick design.  Still a runner after all these years, a testimonial to the solid components in this odd-fire, fiesty engine.  Best thing that ever happened to a vintage Kaiser era Jeep CJ and the Jeepster.  The L- and F-head four cylinder designs from Willys left a lot to be desired.

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Not a fan of open face air cleaners on any 4x4 used for stream crossing.  A bow-wave will not prevent water from sucking through the radiator or sloshing into and through that air cleaner, causing hydrolock.  Edelbrock makes quality products—for the street.

Moses

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  • 4 weeks later...

Good evening!! Been a while...working on fuel issues now. Starves out. Carb was supposed to have been rebuilt according to the old boy we bought it from. Going to check for a filter behind the carb inlet. What pressure range should the 2 barrel run at? Pulling the mechanical pump and converting to electric. Thanks in advance!!

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B Rad...There are a few possibilities:  1)  as you suggest, lack of fuel pressure and volume from the tank to the carburetor, 2) a sticky carburetor float and needle or 3) a low float level setting. 

You can check fuel pump pressure and volume with a "T" fitting from the fuel line between the pump and the carburetor.  Pressure with the engine idling should be a minimum of 3-3/4 PSI with the vapor return hose (if equipped) squeezed off or 2-1/2 PSI minimum with vapor hose open.  Buick recommended a fuel pump output of 4-1/4 PSI to 5-1/2 PSI for its passenger car engines.  The difference depends upon the rpm when testing the pump.  More importantly, there should be steady fuel flow and good fuel flow volume.

If the pump pressure is low, this could be either the pump diaphragm or a badly worn pump drive eccentric at the front of the camshaft, which causes a short pump stroke.   In either case, an electric pump would be one solution.  This engine's fuel filter is a canister between the pump and carburetor, there shouldn't be a carburetor inlet filter.  If the pump is putting out the correct pressure and volume, check the carburetor for a low float level setting or a sticking needle.  Float level is important.

The 2G series carburetors are easy to rebuild.  A rebuild kit with gaskets and a new needle/seat is still readily available.  If necessary, do a bench rebuild of the carburetor and pay close attention to each of the linkage adjustments shown in the kit's instructions.  A factory service manual reprint is available and very helpful for this work.  Correct gasket positioning is important to avoid blocking fuel and air passages.

Make sure that the PCV  valve works properly with vacuum hoses routed correctly.  This is an inexpensive item that can cause tune and performance issues.  If the fuel system and carburetor check okay, check the vacuum and centrifugal spark timing.  With Prestolite distributors, I always look for defective/worn distributor shaft bushings and erratic dwell readings.  Fortunately, you have the Delco-Remy distributor, much more reliable.

Moses

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