What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Holley experts I need your help (FIXED IT)

mrdrinksalil

mrdrinksalil

1/2 ton status
Joined
Apr 4, 2005
Posts
1,618
Reaction score
60
Location
Atlanta, Georgia
Hey guys I have a somewhat brand new 670 truck avenger on my 350 and I went to putt around in the back yard with the truck today and very quickly ran it out of gas before it was even warmed up. No biggie just put 5 gallons of good gas in it that I bought the other day for the lawn mower. Well now it aint runnin right. Stumbles real bad, wont idle. Acts like not enough fuel (or flooded) at idle and way too much fuel when I rev is up. There was some fuel on the linkage side of the carb puddled up on the manifold and the linkage for the secondary was wet. there was also a ton of fuel on top of the butterflys for the secondarys (sp?) . Anyone know whats goin on???? I loved my truck avenger until about 30 min ago.
 
Last edited:
I just went out to investigate further and it ran great for about 5 seconds cause it wasn't flooded and after a min o it finaly flooded itself to the point where it wouldn't run without giving it a lot of pedal. I looked under the hood and saw one of the secondary venturi booster dumping fuel...

Whats causing this>?
 
Thats kinda what I was thinking. Any quick way to get it unstuck or do I gotta take the carb apart??

I was reading up on holleys website and saw this too.

"QUESTION After I shut my car off and come back out the next morning there is gas on the throttle shaft and puddled on the intake. What causes this?
ANSWER This is usually caused by percolation. This is when the engine is shut off and the engine temperature rises it causes the fuel to boil in the bowl and leak out of the boosters. There are a couple of things you can do to cure this one is make sure the fuel level is not too high. You can also lower the fuel level about 1/8" below the sight plug hole and this will cure it sometimes. The heat from the engine will rise into the carburetor sometimes and will cause the fuel to boil. Installing a phenolic heat spacer between the carburetor and the intake or a heat shield can cure this. These parts will prevent heat from getting to the carburetor and boiling the fuel. "

The truck has been sitting in the sun all day and its like an oven under that hood.
 
Running the tank empty has no doubt brought some crud up into the needle and seat. You're probably going to need to remove the float bowl and clean out the debris. If you don't have a fuel filter inline somewhere you need to get one and if you do already have one you need to change it now. The worst thing you can do is to run out of fuel just for this simple reason.
 
I had the exact same problem before on basically the same carb. It was a stuck float caused by the secondary needle seat being bad. They come new in a rebuild kit and you don't even have to take the bowl off the carb to replace it either.
 
Welcome to the wonderful world of Holley. Get used to tearing it apart.
You will soon become very intimate with it.
Kinda like zen bhudaism.................... I will become one with my carb...............
Oooohhmmmmmm
 
Had a brand new holley on my new 350 I bought from a friend

threw it away and put my 30 year old Qjet on it...
 
yeah, I just have a small screen type filter between the pump and carb. It has a bit of junk in it but I didn't think it would get past the line. The fuel lines and fuel call are all new but the pump was old and had some crud in it. I have a big summit paper filter type that isn't on it but maybe I should put it on.

Looks like I might be going propane sooner than planned if I have to get intimate with this carb frequently.
 
I had a Truck Avenger with the same problem. I chased that SOB around for over a year and could never get it to run right. I ended up throwing it away and putting an Edelbrock on it. Runs great now.
 
I did that with my demon...but i sunk the float.

I prefer my demons over my old Q-jet. Maybe it's because I don't understand how to tune Q-jets... haha
 
Everyone gets fustrated with Holleys because either they have the wrong Holley for their application or they don't spend the time attempting to understand the carb to tune it right. The secret to tuning Holley carbs is all over the internet, in fact this site has quite a bit of good info too as well as many who are well versed in Holley tuning.
 
well I pulled the carb off the truck and took of the secondary float bowl. found only a tiny tiny bit of sludge at the bottom of the seconday metering body down by the jets. The float and needle seat all looked fine. what do I do now? Could there be something stuck in the metering body?
 
mrdrinksalil said:
well I pulled the carb off the truck and took of the secondary float bowl. found only a tiny tiny bit of sludge at the bottom of the seconday metering body down by the jets. The float and needle seat all looked fine. what do I do now? Could there be something stuck in the metering body?
Click to expand...

Throw a rebuild kit in it - gaskets, needles. Blow the metering blocks and air bleeds out with air while you're at it. Of course, check for vacuum leaks as well.
 
rcamacho said:
Throw a rebuild kit in it - gaskets, needles. Blow the metering blocks and air bleeds out with air while you're at it. Of course, check for vacuum leaks as well.
Click to expand...

I'll try blowing out the metering block but as for "throwing a rebuild kit in it" goes I'm going to politely say No... I dont see throwing parts at a carb with about 3 total hours of run time. Mechanics who throw parts at trucks are about as worthless as broken axle shafts IMO. I'm an engineer for a major equipment company who makes a living helping dealer techs diagnose complex hyd/ diesel engine/ powertrain issues when they dont know what to do. I dont "thow parts at" anything. If I did I wouldn't be worth a d*mn at what I do and the warranty department would prolly wanna kill me eventually. I see dealers do this to customers all the time and can't help but feel bad for the customer when hes just got a $10,000 service bill cause the tech couldn't find a little metal fragment in a valve. And if he would step back and think he'd know right where that metal fragment was in a huge control valve stack without even picking up a wrench.

I will however pleed ingnorance on Holley carbs cause this is my first...
what in that metering block keeps fluid from getting up into the nozzle?? as this point I'm thinking the float was just stuck or float needle stuck with a piece of trash in it that I didnt see fall out when I got the bowl off.
 
Excess fuel pressure? My truck avenger didn't like the 9 psi that my BIG holley mechanical pump made - flooded at low rpms and made it difficult to tune
 
mrdrinksalil said:
I'll try blowing out the metering block but as for "throwing a rebuild kit in it" goes I'm going to politely say No... I dont see throwing parts at a carb with about 3 total hours of run time. Mechanics who throw parts at trucks are about as worthless as broken axle shafts IMO. I'm an engineer for a major equipment company who makes a living helping dealer techs diagnose complex hyd/ diesel engine/ powertrain issues when they dont know what to do. I dont "thow parts at" anything. If I did I wouldn't be worth a d*mn at what I do and the warranty department would prolly wanna kill me eventually. I see dealers do this to customers all the time and can't help but feel bad for the customer when hes just got a $10,000 service bill cause the tech couldn't find a little metal fragment in a valve. And if he would step back and think he'd know right where that metal fragment was in a huge control valve stack without even picking up a wrench.

I will however pleed ingnorance on Holley carbs cause this is my first...
what in that metering block keeps fluid from getting up into the nozzle?? as this point I'm thinking the float was just stuck or float needle stuck with a piece of trash in it that I didnt see fall out when I got the bowl off.
Click to expand...

A rebuild kit isn't "thowing parts" at it. A kit includes all the gaskets and seals you could ever need including the ones you will need to put this carb back together. And conveniently a kit includes the needle seats, so as preventative maintenance you might as well replace them. A complete genuine Holley rebuild kit is on the expensive side but you still have a ton of parts left over that you can use later.

No one has doubted your knowledge on diagnosing strange problems on diesels, but you have to replace the gaskets when you take a carb appart, and they are only available in a rebuild kit.
 
mrdrinksalil said:
I'll try blowing out the metering block but as for "throwing a rebuild kit in it" goes I'm going to politely say No... I dont see throwing parts at a carb with about 3 total hours of run time. Mechanics who throw parts at trucks are about as worthless as broken axle shafts IMO. I'm an engineer for a major equipment company who makes a living helping dealer techs diagnose complex hyd/ diesel engine/ powertrain issues when they dont know what to do. I dont "thow parts at" anything. If I did I wouldn't be worth a d*mn at what I do and the warranty department would prolly wanna kill me eventually. I see dealers do this to customers all the time and can't help but feel bad for the customer when hes just got a $10,000 service bill cause the tech couldn't find a little metal fragment in a valve. And if he would step back and think he'd know right where that metal fragment was in a huge control valve stack without even picking up a wrench.

I will however pleed ingnorance on Holley carbs cause this is my first...
what in that metering block keeps fluid from getting up into the nozzle?? as this point I'm thinking the float was just stuck or float needle stuck with a piece of trash in it that I didnt see fall out when I got the bowl off.
Click to expand...

My bad for not reading the entire post. If fuel is leaking out of the boosters or vents excessively it's either float adjustment, float leak/interference or excessive fuel pressure.
 
yeah I think it was just some trash between the needle and seat for the float that I didn't see fall out. I'm just gonna put it back together, check the float height and see what happens.
 
Put the carb back on the truck and she runnin like a champ again. Put the sight glasses in to check float height and the rear is just a little too high but its hard to say cause its not on the road and I didn't have anywhere to really let the secondarys open up so I might leave them for now. Thanks for the help guys. This site has saved my a** more times than I care to admit.:bow: Back to roll cage building 101 now.
 
You must log in or register to reply here.

Latest Posts

Top Bottom