Truck died last night

[chrismoore701]

Took the truck for a 30 mile ride last night and it died at intersections a couple times. Truck has been running great until now. Start to diagnose it last night. Has 430 miles on it. Maybe the fuel filter. Looks clean. Maybe the trans is bogging the motor down, nope started to die before I came to a rest. 3:00 in the morning. Ah ha. What have I done to the truck in the last day? Replaced the gas cap. Looks like the old one is going back on. Bought the new one for $1. I think I can afford to throw it away

Just wanted to share

[chrismoore701]

So I changed the gas caps back and she is still dying out when I slow to a stop. Plan to check the fuel filter but I have 450 miles on the motor. But this is a total frame off wonder is something got into the tank and clogging something up. Any thoughts?

[hatzie]

What RPM do you have the idle set to?
Did you set the idle in gear? Assuming it's an automagic transmission.

[cadillac_al]

The first thing I do when a vehicle dies is pop the breather off and look down the carb and pump it to see if it has gas. If the gas stream is strong then it is time to check fire. If it has fire too then something is out of adjustment.

[chrismoore701]

I am not sure about the rpm. It was set real good. I increased Kathy 200 rpms and now it is hard to stop so I know it is too high. And that didn't help. I will check the squirters. I am fully convinced that it is fuel by the way it is starving and dieing out. Everything is new on the motor. Not saying it is not the electronics. How would I check that? It runs good if I pop it out of gear. I do know my Trans fluid is low and it is not shifting right. Need to have that looked at. But the motor is stalling out when I slow down before I stop

[chrismoore701]

What about a. Vacuum leak? Especially for the Trans line?

[nonstop]

Originally Posted by chrismoore701

What about a. Vacuum leak? Especially for the Trans line?

Or the booster...

[wilkin250r]

I second the vacuum leak idea. Any time I get a motor that doesn't want to idle, my first three suspects: Idle mixture. Idle setting. Vacuum leak. It sounds like you've tried the second, I assume you tried the first.


What kind of carb are you running? Maybe putting the vacuum advance on manifold vacuum rather than a ported vacuum? (after you check for a vacuum leak, of course)

[Wgesnerjr]

Carb float setting?

[chrismoore701]

Here is the set up
Brand new holly 650
Booster hooked to intake
Pcv valve to the base of the carb
Trans to a small front port
No advAnce hooked up. My engine builder said he installed an advance delete kit
Notice the Trans is shifting fast. I got on it the other day and I was in third before I hit 20 mph

[hatzie]

Don't be so aggressive with idle changes... I usually bump Idle speed up by 50 RPMs at a whack. Try setting the Idle 50 RPM above the original baseline. Original Idle is 650? Set it to 700...

Trans shifting fast... I'm poking around in the dark here. What transmission do you have? Stall speed on the torque convertor? What engine is this behind?
Holley 650. Did you buy the correct Holley 650 model Throttle Valve cable or Kickdown cable bracket for your carburetor?
3rd by 20MPH at light to medium throttle seems, at first blush, to be too aggressive for a TH350 but it would be almost OK on a TH700R4. Is she bogging on this shift?
Make sure the Kickdown cable on the TH350 or the TV cable on the TH700R4 is properly adjusted.

PCV should be at manifold vacuum. I doubt that's your problem tho.

Vacuum leak... Maybe the vacuum brake booster?

Who set the idle mix and float level(s) on your Holley?

What's the fuel pressure? Holley carbs always seemed to be a bit less forgiving than the Rochester Quadrajet and 2G on fuel pressure. You either love em or hate em... I found Holley carbs to be fairly temperamental so I'm not a fan... but they can be made to perform very well if you're willing to tinker with them.

[chrismoore701]

I have a mild built 350 bored out. About 375 horse. Turbo 350. No stall. New everything. Went home tonight and checked things out. Does not seem to have a vacuum leak. Sprayed carb cleaner around the carb to see if I could hear a change in rpm. Well that didn't show anything. Going to change the little line from the Trans to the carb. Pretty loose at the carb. But seemed to have a good seal

[Super_Dave]

Vacuum diaphragm in the brake booster can develop a hole, causing a leak and a stall condition when stopping.

[Gregski]

where is your fuel filter and what kind is it, I had a similar problem with one of them fancy shmancy chrome and glass ones right in front of my carb, I tossed it and went back to the bulky ugly plastic one and no problems since

[chrismoore701]

I have that one in front of my carb about 10 inches away.

[chrismoore701]

Originally Posted by Super_Dave

Vacuum diaphragm in the brake booster can develop a hole, causing a leak and a stall condition when stopping.

How do you test it?

[Gregski]

Originally Posted by chrismoore701

I have that one in front of my carb about 10 inches away.

Yank it

[hatzie]

Originally Posted by chrismoore701

How do you test it?

With the engine off, pump the brake pedal to remove any residual vacuum in the booster. The pedal will get very stiff.
Hold pressure on the pedal while you start the engine. When the engine starts, the pedal should drop some, this indicates that the assist function of the booster is working properly.
Let the engine idle for two minutes. Just before you turn off the engine, push down on the brake pedal and hold it. Turn the engine off, and then continue holding your foot on the pedal for another 30 seconds. If the pedal stays where it is, then the brake booster probably isn't leaking because it can maintain a vacuum.

You can test the booster with a vacuum gauge and vacuum pump. Here's how.

http://ssbrakes.com/attachment/85301...0Diagnosis.pdf

Originally Posted by Gregski

Yank it

Most inline filters cause fuel supply headaches.
Most Holley carbs have bronze or paper filter(s) on the side of the float bowls inside the fuel feed fitting(s). If these filter(s) plug up quickly you need to clean or replace your fuel tank(s).

On my 1976 K20 and 2000 C2500 GMC 6.5L Diesels I have a Racor 645 45gph filter/water separator just after the tank valve or fuel pump. I mounted it high on the frame rails. I use an R45T ten micron element in the Racor and a Baldwin BF1201 five micron element in the GM Stanadyne FFM on the rear of the 6.5L intakes. I mostly fill out of a 1,000 gallon storage tank. The storage tank fuel pump has four spin on filters ranging from thirty to two micron and two Gulf Coast F-1 filters on a recirculating pump that I run for @ 24 hours after a delivery. That's roughly 3 passes through the F-1 filters. Much easier to strip the crud and water out in storage before it gets to the fuel tanks on my machinery. No water and low crud = no algae.

My onboard setup is overkill for gasoline... However. If it gives you warm fuzzies... the Racor 645 will filter gasoline just as well as diesel fuel. The elements are available for either and the hard parts don't care what liquid you run through them. You could install one on the frame just after the tank valve. The elements come in two to thirty micron. Ten or even twenty micron elements are plenty fine for gasoline.

[Gregski]

Originally Posted by chrismoore701

I have that one in front of my carb about 10 inches away.

look familiar, this was my smoking gun

[chrismoore701]

That's what I have. But not mounted like that. I am going to pull it apart and clean it with carb cleaner and see what that does. What was your problem that caused you to replace it?

[Gregski]

Originally Posted by chrismoore701

That's what I have. But not mounted like that. I am going to pull it apart and clean it with carb cleaner and see what that does. What was your problem that caused you to replace it?

truck would start fine, run and drive ok for a little while, but would barely take me to the closest gas station, it would want to die at Stop signs, and was hard to start after I turned it off at the gas station to get gas

removed and replaced that fuel filter with this one and no more problems

[chrismoore701]

See I would agree that like be a filter issue. Mine sputters and dies when I stop. But fires right back up and drives great until I slow down again

[chrismoore701]

My setup. You can see the location of the filter.

[hatzie]

Unless Holley has made drastic changes there should be bronze or paper filters and bypass springs behind the inlet fittings just like the Rochester carbs.

You shouldn't need another filter if your tank isn't rusty and nasty.

http://www.vintagemusclecarparts.com...terservice.pdf


Holley also made full flow filters for the 4100 series, on Ford and GM cars and trucks, that threaded into or replaced the fuel intake fitting on the carburetor. Not sure about availability. Autolite 9155A is one of them...

[jjzepplin]

If you have a turbo 350 it does not have vacuum at the carb. It is supposed to be manifold vacuum at the rear of the carb there is a fitting that screws into the manifold and goes to the vacuum modulator on a th350. The modulator is sometimes adjustable to fine tune your shifting. You may have the trans connected to ported vacuum and this would be not so good.