THANK YOU SIR!!! i just bought an 86 squarebody for my step father and he loved it but it was gutless. found out the old carb had an issue with the rod for the secondary... got a "new" holley 4 barrel exactly like the one you have here and it would bog and even stall on takeoff sometimes. i made every adjustment i could think of until watching this video and it made perfect sense! found out my pump arm was bent up exactly where yours was but id say more like 1/4"!! i did the vice fix you did and she SCREAMS now buddy!!! i absolutely NEVER would have known this! lifesaver!!! (subscribed and deleted the unsubscribe button)
I currently run with a Holley Street Avenger 770 carb on a ZZ4 engine, and respect to the accelerator pump arm, those were somewhat problematic and needed adjustment. The lever end that was supposed to ride on the pump cam(green/1 position), was actually sitting on the return spring. So as you progressed, it would finally start riding on the pump cam, that was causing a slight bog as soon as you hit the accelerator. So the cure was to bend the the arm that rides the pump cam upwards about an 1/8th of an inch so the heel of the lever would actually rest on the pump cam at the carb's resting position.
I've been having an horrible bog/backfire through the carb issue with my 0-1850S for years now that makes it mostly undrivable (can't get enough juice to cross a street quickly without stalling) and could never figure it out. Was just about to begrudgingly slap on an Edelbrock carb or an EFI kit as a last ditch attempt at making the vehicle run. Well I watched your video and sure enough, the rocker arm is as straight as Elton John. I'm going to bend it flat and give this a shot. Fingers crossed! It is really strange that all of them I could find online are also bent, seems intentional to me, but if it works it works! Thanks for the video!
Figured I would post an update.. Car is a 78 Cherokee S with an AMC 360. Ended up confirming the vacuum advance was working. Checked all my wires and inspected the HEI distributor, all looked good. Thanks for the tip though, good to know it can cause that issue. Decided to check timing one more time for good measure and ended up making a change of about 20 degrees before it sounded great by ear! Now there is no more issue. In fact, I can't even get it to backfire on WOT. I feel silly for assuming the timing was still set correctly but sometimes it's the simple things. I'll keep your fix in mind for future diagnosis. Cheers
@@Foxcanfixithave you ever found the the arm, where it rides the cam, is wide enough to rest on the throttle shaft spring next to the cam? I have found 2 like that. The throttle lever pulled about 3/8“ before the arm even contacted the cam.
So would you say that your carb had a Bog from lack of fuel? I am having similar issue with my Holley. From idle to WOT or really any position off idle it I just give it a quick slam it bogs and then takes off but it sounds and acts like it flooding and getting to much fuel
Yes mine was lean due to no pump shot because of the bent accelerator pump arm. Your issue sounds like your secondaries open too soon. Is it a vacuum secondary carb? If so get a Holley vacuum secondary spring kit and a quick change cap. Install a heavier spring so your secondaries open a little later
THANK YOU SIR!!! i just bought an 86 squarebody for my step father and he loved it but it was gutless. found out the old carb had an issue with the rod for the secondary... got a "new" holley 4 barrel exactly like the one you have here and it would bog and even stall on takeoff sometimes. i made every adjustment i could think of until watching this video and it made perfect sense! found out my pump arm was bent up exactly where yours was but id say more like 1/4"!! i did the vice fix you did and she SCREAMS now buddy!!! i absolutely NEVER would have known this! lifesaver!!! (subscribed and deleted the unsubscribe button)
That’s great! I’m glad it worked for you. It’s not always the problem, but it’s something to check for sure.
Been messing with these for along time, it’s a science to get them right sometimes
Sometimes it’s also an art 😀
I currently run with a Holley Street Avenger 770 carb on a ZZ4 engine, and respect to the accelerator pump arm, those were somewhat problematic and needed adjustment. The lever end that was supposed to ride on the pump cam(green/1 position), was actually sitting on the return spring. So as you progressed, it would finally start riding on the pump cam, that was causing a slight bog as soon as you hit the accelerator. So the cure was to bend the the arm that rides the pump cam upwards about an 1/8th of an inch so the heel of the lever would actually rest on the pump cam at the carb's resting position.
I have recently found a grand new pump arm that was just like that too! What the heck is going on with manufacturing right now?
I've been having an horrible bog/backfire through the carb issue with my 0-1850S for years now that makes it mostly undrivable (can't get enough juice to cross a street quickly without stalling) and could never figure it out. Was just about to begrudgingly slap on an Edelbrock carb or an EFI kit as a last ditch attempt at making the vehicle run.
Well I watched your video and sure enough, the rocker arm is as straight as Elton John. I'm going to bend it flat and give this a shot. Fingers crossed! It is really strange that all of them I could find online are also bent, seems intentional to me, but if it works it works!
Thanks for the video!
Also have you checked your vacuum advance if you have one? A bad vacuum advance would do this too
That is a good idea, I have not checked the vacuum advance (it does have one). I'll bust out the timing light too. Thanks :)@@Foxcanfixit
Figured I would post an update..
Car is a 78 Cherokee S with an AMC 360.
Ended up confirming the vacuum advance was working. Checked all my wires and inspected the HEI distributor, all looked good. Thanks for the tip though, good to know it can cause that issue.
Decided to check timing one more time for good measure and ended up making a change of about 20 degrees before it sounded great by ear! Now there is no more issue. In fact, I can't even get it to backfire on WOT. I feel silly for assuming the timing was still set correctly but sometimes it's the simple things. I'll keep your fix in mind for future diagnosis.
Cheers
@@zacharya6833 man that’s great! A free fix is the best fix! Glad you found the issue. 👍😀🤜
@@Foxcanfixithave you ever found the the arm, where it rides the cam, is wide enough to rest on the throttle shaft spring next to the cam? I have found 2 like that. The throttle lever pulled about 3/8“ before the arm even contacted the cam.
Great breakdown and visual to help understand!
Great job 👍
Great video. My pump shot only utilizes half the diaphragm stroke. I think someone fussed with the arm.
Make sure you check out Holleys online instructions. They can walk you thru checking and adjusting everything to narrow the culprit.
See this is the kind of classes i can pay attention too ha ha! good video brotha!!!
Thanks man! I did a lot of refresher reading on this one.
the fuel goes drippy drippy like its supposed to 😂
Good info, thanks for sharing!
So would you say that your carb had a Bog from lack of fuel?
I am having similar issue with my Holley. From idle to WOT or really any position off idle it I just give it a quick slam it bogs and then takes off but it sounds and acts like it flooding and getting to much fuel
Yes mine was lean due to no pump shot because of the bent accelerator pump arm. Your issue sounds like your secondaries open too soon. Is it a vacuum secondary carb? If so get a Holley vacuum secondary spring kit and a quick change cap. Install a heavier spring so your secondaries open a little later
I wonder if the accelerator pump was stuck from sitting and the cam bent the arm before the pump popped free.
That is possible, I got it as a used carb. I have seen people bend them instead of changing pump cams too.
nice drawing!
@@ebifurai415 thank you! I can’t to auto cad, but I can do sharpie and cardboard
@@Foxcanfixit sometimes a simple visual is all you need!
Great video
Thanks!
Interesting! Thanks
7:47 you can skip here for the answer