|
|
 Holley Truck Avenger rear float
#949160
06/12/09 06:24 PM
|
Joined: Sep 2005
Posts: 1,087
OP
Body Damage is Cool
|
I have a relatively new Holley 670 cfm Truck Avenger carb on the AMC 360 in my CJ7. On a couple of occasions, the needle on the rear float has stuck closed. When that happens, the engine immediately bogs down (usually dies) when I stick my foot in it going uphill and the vacuum secondaries open. When that happens, all I have to do is tap the rear of the carb with a screwdriver handle and it will unstick the needle (the float is adjusted properly) and it will usually work properly for the rest of the day.
Is there something special that I can clean the needle and seat with to prevent this from happening? Do I have to replace the needle and seat?
Thanks in advance for any suggestions.
--Bob
1977 CJ-7, fiberglass body, AMC 360 w/ headers, DUI ignition, Edelbrock intake and Holley 4150 carb, TF999, Dana 300, 4.56 gears lockers, York air comp, 4" susp lift, 2" body lift, BFG 35" M-T tires, Megashifter, AGR pump & box, REP8000 winch.
|
|
 Re: Holley Truck Avenger rear float
[Re: BobRowe]
#949161
06/12/09 07:36 PM
|
Joined: Oct 2003
Posts: 7,768
Web Wheeler
|
Bob, I'm thinking you are WRONG! Since the needle is pushed open by fuel pressure, 6 or 7 pounds, and it appears you have assured yourself the needle isn't clogged up with crud inside the seat... Your problem is the float being misaligned. It isn't floating as it should. When at full-bowl the float is hanging, probably on the side of the bowl...but the hang could be anywhere along the length of the float. When you tap on the carb you are dislodging the float which allows it to drop and the needle is allowed to open for more fuel. Your float is holding the needle shut! Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />
professional bovine relocation specialist
|
|
|
Re: Holley Truck Avenger rear float
[Re: BigJim]
#949162
06/12/09 10:19 PM
|
Joined: Sep 2005
Posts: 1,087
OP
Body Damage is Cool
|
Sounds good, BJ, except the first time it happened I didn't think to tap on the carb. I just restarted the engine and drove on mild hills that didn't require the additional power of the secondaries.
When I got back, I took it to a highly rated tune-up shop in the area. They put it on a dyno where they could load it down and get the vacuum secondaries to open. When they did, the engine leaned out so badly it quit. They took the float bowl off and found that the float was operating correctly, but that the needle was stuck in the seat. They dislodged it, put the bowl cover back on and (using the sight gauge) said that the float was adjsuted correctly. They suggested that I try it again, and if it acted up again to change the needle and seat.
It did act up a couple more times on the trail, but tapping it fixed it (at leas temporarily). I figure I'll have to replace the needle and seat, but since the thing is practically new, was wondering if I should clean up the needle and seat (even if I put in a new one) with something that might help prevent sticking.
Also, on a subsequent occasion when it did it on the trail, we removed the float bowl right after the engine quit. The bowl was not full of fuel, it was almost empty. So, that makes me think that it's a case of the needle sticking closed, not sticking open. Also, due to the design of the TA float bowls, I don't see how a mis-aligned float could hang up on the side of the bowl.
Is there something I'm missing here?
Last edited by BobRowe; 06/12/09 10:20 PM.
1977 CJ-7, fiberglass body, AMC 360 w/ headers, DUI ignition, Edelbrock intake and Holley 4150 carb, TF999, Dana 300, 4.56 gears lockers, York air comp, 4" susp lift, 2" body lift, BFG 35" M-T tires, Megashifter, AGR pump & box, REP8000 winch.
|
|
|
Re: Holley Truck Avenger rear float
[Re: BobRowe]
#949163
06/13/09 12:25 AM
|
Joined: Oct 2003
Posts: 7,768
Web Wheeler
|
Sounds good, BJ, except the first time it happened I didn't think to tap on the carb. I just restarted the engine and drove on mild hills that didn't require the additional power of the secondaries.
When I got back, I took it to a highly rated tune-up shop in the area. They put it on a dyno where they could load it down and get the vacuum secondaries to open. When they did, the engine leaned out so badly it quit. They took the float bowl off and found that the float was operating correctly, but that the needle was stuck in the seat. They dislodged it, put the bowl cover back on and (using the sight gauge) said that the float was adjsuted correctly. They suggested that I try it again, and if it acted up again to change the needle and seat.
It did act up a couple more times on the trail, but tapping it fixed it (at leas temporarily). I figure I'll have to replace the needle and seat, but since the thing is practically new, was wondering if I should clean up the needle and seat (even if I put in a new one) with something that might help prevent sticking.
Also, on a subsequent occasion when it did it on the trail, we removed the float bowl right after the engine quit. The bowl was not full of fuel, it was almost empty. So, that makes me think that it's a case of the needle sticking closed, not sticking open. Also, due to the design of the TA float bowls, I don't see how a mis-aligned float could hang up on the side of the bowl.
Is there something I'm missing here? Yes Bob you are missing the 7 pounds of fuel pressure that is pushing against the needle at all times the engine is running. You would have to have a BUNCH of crud in the needle area to hold that much pressure. However, the length of the float overcomes the 7 pounds rather easily.. In the past I have opened and adjusted hundreds of carbs. The only ones that had stuck needles were carbs that had setup with gasoline in them and the varnish had stuck the needle to the sides of the seat. Even these went back to work after loosening and cleaning the needle and seat area. Many times a sticking float must be CLOSELY examined to find the problem. But you seem to be ready to install a new one so go ahead and see if it repairs your problem. Bad needles usually slowly leak and cause a rich condition. You have the opposite. Remember there is constant 7 pounds of pressure trying to push the needle open. Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />
professional bovine relocation specialist
|
|
|
Re: Holley Truck Avenger rear float
[Re: BobRowe]
#949164
06/13/09 12:38 AM
|
Joined: Sep 2005
Posts: 692
Rock Warrior
|
This may be a bit of a long shot, since itÆs been a few years since I have had the Holley 4150 series on my Ford apart, so I canÆt remember all the details of the guts. I have recently been inside the carbs on a handful of my yard equipment engines though, and all of them had a little wire clippy piece connecting the float to the needleà Should there be one connecting the needle to the float on the Holley? I honestly canÆt remember, I am just throwing the idea out there.
If it were me, I would pull the needle and seat out and look at them, and see what I see. Maybe there is a bur, or a piece of debris, or something in there that is hanging things up that could be cleaned up.
I wouldnÆt ever put anything in a carb ôthat might help prevent stickingö other than fuel, or carb cleaner though.
I am surprised the fuel pressure is not enough to push the needle down though, are you sure the inlet to the secondary bowl is not plugged with something? Thinking since the carb is ôrelatively newö maybe there is a piece of shipping/ packaging debris that is between the fuel inlet tube and the bowl, and it is just too big to pass through, but its small enough to move around in the fuel tube area and sometimes plug things up.
Like I said, if it was me, I would be taking things apart and taking a look.
Sean
99 XJ Sport 2 Door, 4.0L, 5 speed, all stock. Daily Driver
79 F150 Standard Cab Short Box, 400ci, NP435, NP205, 35" SSRs
|
|
|
Re: Holley Truck Avenger rear float
[Re: BigJim]
#949165
06/13/09 02:33 AM
|
Joined: Feb 2000
Posts: 6,247
Trail Leader
|
I have been fuel injection for a few years but did the carb battles in a 304 with both Holley and Motocraft carb.
Personally, the Holley was a waste of money. I had constant problems with float and needle. I did have great success with changing the jets to where it was great in slow speed off-road performance but would not go more that 50 mph on highway. However, it appeared as fuel pressure was a culprit.
Overall, my best performance was when I added a fuel regulator to keep a constant 7 lbs pressure. However, that was not a consistent fix as the mechanical fuel pump can at times drop below its rated level and cause problems.
I finally went back to a Motocraft 2100 that was jetted for high altitude. Once adjusted, the engine ran smooth. However, I needed to adjust it frequently....
In short, check fuel pressure; it may be a fuel pump issue. Other than that, due to the quality of fuel, you may need to be running some type of cleaner solution to keep the needle moving free.
|
|
|
Re: Holley Truck Avenger rear float
[Re: 4x4Wire]
#949166
06/14/09 06:18 PM
|
Joined: Sep 2005
Posts: 1,087
OP
Body Damage is Cool
|
Thanks for everybody's suggestions. I'll take it apart and see what I can see.
1977 CJ-7, fiberglass body, AMC 360 w/ headers, DUI ignition, Edelbrock intake and Holley 4150 carb, TF999, Dana 300, 4.56 gears lockers, York air comp, 4" susp lift, 2" body lift, BFG 35" M-T tires, Megashifter, AGR pump & box, REP8000 winch.
|
|
|
Re: Holley Truck Avenger rear float
[Re: BobRowe]
#949167
06/17/09 05:10 AM
|
Joined: Sep 2005
Posts: 692
Rock Warrior
|
alright, it's been 3 days, what did you see?  Sean
99 XJ Sport 2 Door, 4.0L, 5 speed, all stock. Daily Driver
79 F150 Standard Cab Short Box, 400ci, NP435, NP205, 35" SSRs
|
|
|
Re: Holley Truck Avenger rear float
[Re: Bigbird79]
#949168
06/18/09 07:38 AM
|
Joined: Sep 2005
Posts: 1,087
OP
Body Damage is Cool
|
alright, it's been 3 days, what did you see? Sean Got a broken foot that is flaring up. It will be a while 'til I get a chance to work on the CJ.
1977 CJ-7, fiberglass body, AMC 360 w/ headers, DUI ignition, Edelbrock intake and Holley 4150 carb, TF999, Dana 300, 4.56 gears lockers, York air comp, 4" susp lift, 2" body lift, BFG 35" M-T tires, Megashifter, AGR pump & box, REP8000 winch.
|
|
|
Re: Holley Truck Avenger rear float
[Re: BobRowe]
#949169
06/19/09 06:24 AM
|
Joined: Sep 2005
Posts: 692
Rock Warrior
|
alright, it's been 3 days, what did you see? Sean Got a broken foot that is flaring up. It will be a while 'til I get a chance to work on the CJ. My apologies sir. I wish you and your jeep a speedy recovery. DonÆt I feel I like an ass now. Damn the curiosity in my to want to try to fix everything. <img src="/forums/images/graemlins/cheers.gif" alt="" /> Sean
99 XJ Sport 2 Door, 4.0L, 5 speed, all stock. Daily Driver
79 F150 Standard Cab Short Box, 400ci, NP435, NP205, 35" SSRs
|
|
|
|
