MKII stalls after reaching operating temperature

[o2bdriving]

I think I may know the source of your misery, that is, IF that Holley is the "center pivot" style of fuel inlet. Going on 7 years ago, we fought a similar problem on the return to Oregon from SUNI in Colorado Springs. The car would run fine for a while, then start to bog, losing power. Seemed to have good fuel pressure, and to help, we bought bags of crushed ice to improve fuel pump pressure. Made it all the way home with some creative driving!! I was certain is was a fuel related problem. I FINALLY found the problem! Both carburetor fuel filters, front and back, were badly restricted. I will never forget the euphoric feeling when I blow tested those two filters and knew I had finally nailed it!!
Gary Haslip

Thanks Gary, looking forward to eureka moment. Yeah, my carb doesn't have the center pivot or Banjo fitting for the fuel inlet.

 

[o2bdriving]

You might want to consider a spacer. I had this issue back when my MK I was my daily driver. There's a real possibility that the warmed up engine is boiling the fuel in the carb bowls and causing starvation. I was running a Holley straight on top of an F4B then.
Check everything else - fuel pressure, spark etc. after it has warmed up to eliminate them first.

Added a Fuel Pressure Gauge as well as a Vacuum Gauge. Fuel Pressure is 3PSI which is in line with the SU LP Fuel Pump. Switched out Ballast resistor as was suggested by another. Still stalls after reaching operating temp. Bought a Pertronix Ignitor and will likely install that. Looks simple, just pop out the condenser and points and drop in the Ignitor and wire to coil and Ballast resistor.

 

[pfreen]

Some carburetors have a screen pressed into their fuel inlet. This filter is easy to miss.

 

[o2bdriving]

Some carburetors have a screen pressed into their fuel inlet. This filter is easy to miss.

I'll give a look today. Thank you.

 

[CLIFF_MK1]

Here's some pics of heat shields between gas line and exhaust and muffler and fuel pump on MK1.

 

[o2bdriving]

very nice, love the look of all the stainless. Thank you for sharing.

 

[o2bdriving]

Update: Changed Fuel Pump as the Holley carburetor wants 4-7 psi and the SU pump only delivers 2.7 psi. The SU HP version is 3.7 PSI so put a facet fuel pump in. The starvation issue seems to be resolved. Added LAT fan and the temp seems stable 180-190 while driving. Been enjoyable to drive. Appreciate all of the tips that you provided.

 

[Warren]

Wow, after a few minutes of searching even I wondered where to place a fuel pump question. For those new readers. As a appointee of the first Admin. I/we moved all content then to the current categories. That said please don't worry if you are placing a thread. It takes longer to sausage finger this sentence than to move a thread

Now to the point.
I recently had some fuel problems at the last United. The Holley red pump became overactive and was pushing raw fuel down her throat. Had I not have taken SPMDR advice it could have been a car bque . As I was pulling the air cleaner the fuel was vaporizing and inundating the carb body. He said stop the fuel pump. Luckily the small spark created by the removal of the white wire at the fuse block was not a source of ignition. Apparently the spring check valve had failed as the pump was happily drowning the car.
I limped back to the Hotel by switching the pump on running it dry then repeat.
Part of the road kit is exact replacement of the pump.
Which is only silenced by the throttle and the boom box. As Dan would say it worked fine until it didn't. In this case over 15,000 miles and close to 20 years.

So I'd appreciate your comments on how your stock pump works with a 250 ish R.W.H.P. car. In addition have any used the below service. Better to just buy a new one from S.S. or ? or is it just quicker. The stock S. U. Is quiet but so are the Facet block pumps.


https://www.catmbr.org/cat-forum/resources/categories/tiger-product-and-service-white-pages.3/

 

[o2bdriving]

My 271hp Holley 4-barrel engine wouldn't run with the standard su pump as it was only putting out 2-3psi. Switched to the facet, added a filter and pressure regulator. Still running great.

 

[michael-king]

My 271hp Holley 4-barrel engine wouldn't run with the standard su pump as it was only putting out 2-3psi. Switched to the facet, added a filter and pressure regulator. Still running great.

Psi isnt as much as issue as flow.. High flow low pressure is good for carbs. 😉

 

[Warren]

I have conflicting but some what reasonable opinions.
The new Holley pump mostly requires the boom box or 15 mph to become tolerable.

Steve you you probably have a little more HP than me at 271 . The car isn't built for autocross outside of the usual dialed back first or second gear course. Of course that doesn't include the infamous event where 70% or more had to hit reverse

One suggested his double pump carb may suffer on longer tracks, while another says the brick or cube ones can keep up. Naturally I have the over think it that fuel line I. D. and possibly the capacity of a fuel filter may have some positive effect.

Then there's the SU that is a higher psi then the stock unit. After seeing E type ones with dual motors hoping that is not the solution.

I do have 2 core SU pumps.
Has anyone used the rebuilding service listed in the resource section.

 

[0neoffive]

Back to the original confab: Regardless of fuel pressure (within reason), the carb should have sufficient fuel to run along without stall. If you have a module ignition, they can fail and become sporadic when they get hot. I first stumbled across this type gremlin in the 80's. The tech has not improved and the condition still pops up now & then. just sayin'

 

[Warren]

Well also I like alcohol but my girlfriend not so much.

 

[IvaTiger]

Well also I like alcohol but my girlfriend not so much.

View attachment 16384

Are you saying you like alcohol more than you like your girlfriend 😮

 

[Warren]

My car is my girlfriend, she just doesn't like 10% ethanol at all. The fuel was less than 7 or 8 months old. Mainly because the Hayes device's in Calunicornia make it a major PiTA to fuel a Sunbeam . I'd gotten in the habit of fueling a 5 gallon non CARB motorcycle jug. I'll be more careful keep the caps on really tight and get rid of the discolored Stabil. It was almost as hard on the Falcon to add fuel.

 

[IvaTiger]

My car is my girlfriend, she just doesn't like 10% ethanol at all. The fuel was less than 7 or 8 months old. Mainly because the Hayes device's in Calunicornia make it a major PiTA to fuel a Sunbeam . I'd gotten in the habit of fueling a 5 gallon non CARB motorcycle jug. I'll be more careful keep the caps on really tight and get rid of the discolored Stabil. It was almost as hard on the Falcon to add fuel.

Ah gotcha !