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Dead spot

6058 Views 48 Replies 17 Participants Last post by  95lightiningguy
I got it idling at 1000 rpm, If I put the gas pedal to the floor, She pretty well dies out then kinda comes back to life then revs. I expect foot to the floor rpms to sky rocket. I hace a 770cfm holley truck avenger carb, edelbrock performer rpm air gap intake. I had the truck insured 3 months, it ran great. Then I parked it and while it was parked I swaped on the new intake, Marked the timing but it could be out a tad. I have played with air fuel mixture as well. I cant figure out why its doing this.

EDIT: I dont think its a vacuum leak, I got 21 psi at idle.
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I got it idling at 1000 rpm, If I put the gas pedal to the floor, She pretty well dies out then kinda comes back to life then revs. I expect foot to the floor rpms to sky rocket. I hace a 770cfm holley truck avenger carb, edelbrock performer rpm air gap intake. I had the truck insured 3 months, it ran great. Then I parked it and while it was parked I swaped on the new intake, Marked the timing but it could be out a tad. I have played with air fuel mixture as well. I cant figure out why its doing this.

EDIT: I dont think its a vacuum leak, I got 21 psi at idle.
Sounds like the accelerator pump circuit is not working. Either a ruptured rump diaphgram or the passage from the pump to the metering block has some crud in it.
i agree, check the carb.
timing, reset it for the new intake.
Sounds like the accelerator pump circuit is not working. Either a ruptured rump diaphgram or the passage from the pump to the metering block has some crud in it.
i agree, check the carb.
I'm going to try the timing again, Since someone else thinks it still may be that, The carb is pretty damn well new. If timing dont help Ill try another carb.

timing, reset it for the new intake.
How much taller is the new intake? Say Going from a Torker to a Victor adds much more plenum volume and you will have to have some air moving before stabbing it. What does it act like if you bring it up to 1300-1400 then hit the throttle?
How much taller is the new intake? Say Going from a Torker to a Victor adds much more plenum volume and you will have to have some air moving before stabbing it. What does it act like if you bring it up to 1300-1400 then hit the throttle?
It is quite a bit taller. About 1500 rpm put it too the floor she takes off.

Here is intake height differnce, Cant tell a hole lot in the new intake pic though.





Buddy of mine has the edelbrock performer intake, Just no air gap. When he puts it too the floor it takes off right away.
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It is quite a bit taller. About 1500 rpm put it too the floor she takes off.
If it accelerates after reaching 1500 RPM then you may need to either change the pump cam or move the position so that it comes in sooner.

Look at the pump cam and see if the screw is in the middle hole. If so, move the cam up to the top hole and try that.

http://www.youtube.com/watch?v=eiRIfcrc2yA
If it accelerates after reaching 1500 RPM then you may need to either change the pump cam or move the position so that it comes in sooner.

Look at the pump cam and see if the screw is in the middle hole. If so, move the cam up to the top hole and try that.

http://www.youtube.com/watch?v=eiRIfcrc2yA
Thanks for the video because you had me lost, Im going to check and change that right now

EDIT: I changed that thing to the top hole, Better trottle repsonce, But. Still there, If I gradually push the gas its fine, But as soon as I kick it, it dies out. Gotta be Air/Fuel or timing But neither thing changed that dead spot. Im just uploading a few videos so you can see.
As SOON as the throttle plates START to move it needs to be squirting fuel out of the squirter nozzles. If it doesn't, then adjust what you need to to make it so.....
Rob
As SOON as the throttle plates START to move it needs to be squirting fuel out of the squirter nozzles. If it doesn't, then adjust what you need to to make it so.....
Rob
It's squirting, I was making sure it was getting fuel.. Here is one of the 2 videos, 2nd one just uploading



EDIT: thats about half throttle, If I pin it, it will die. I was just trying to keep it running even though its struggling



wow that video blows ***.
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Can you look into the carb and actually see 2 strong streams of fuel coming out of the squirter when you open the throttle? It doesn't need to be running.
Can you look into the carb and actually see 2 strong streams of fuel coming out of the squirter when you open the throttle? It doesn't need to be running.
Yes I can.

Also, I was playing with the timing and forgot that when I put my dist. back in I remember it not looking right, So I thought maybe I was a tooth out, So I went back a tooth and foward a tooth, Back a tooth it barely cranked over. Forward a tooth it wouldnt even run, Had the timing set normal, well what it was always at, And I pinned the throttle, Backfired out of the carb, I seen flame, Which would mean timing, Which is why I tryed a tooth back and 1 forward. I am lost now. Well I was before but even more now lol
So just tonight I started pissing with it again because the truck is getting insured this wednesday.

I retarded the timing a bit, Didnt check how many degree's.

But it ran alot better, Rpms jumped faster, Only a tad dead spot. But I turn the truck off and then turn it back over it has tough time starting, How come I cant find the happy medium here? Maybe I got a vacuum leak after putting the new intake on since I reused old gaskets on the intake,But they looked to be in perfect shape I just added some more silicone. I also sprayed WD-40 down where the heads meet the intake, No rpm jumpage. fml :eek:
Maybe I got a vacuum leak after putting the new intake on since I reused old gaskets on the intake
Start there. Before you put another minute into diagnostics get some fresh gaskets on the motor. Make sure they are the RIGHT gaskets, too. Lots of people have found out the hard way they should have used CJ/SCJ gaskets and not standard units. I can speak from experience because I'm one of them. No lesson better learned or longer remembered than a know-it-all teenager being undone by their own know-it-all-ness. Three decades later and I can remember it like it was yesterday. So can my father who never misses an opportunity to laugh about it. Again.

Brad
Start there. Before you put another minute into diagnostics get some fresh gaskets on the motor. Make sure they are the RIGHT gaskets, too. Lots of people have found out the hard way they should have used CJ/SCJ gaskets and not standard units. I can speak from experience because I'm one of them. No lesson better learned or longer remembered than a know-it-all teenager being undone by their own know-it-all-ness. Three decades later and I can remember it like it was yesterday. So can my father who never misses an opportunity to laugh about it. Again.

Brad
I dont want to waste 60 bucks on gaskets if thats not the problem, I have blown so much money by just chucking new parts into it, You know a good way to check for vacuum leaks? WD 40 didnt do the trick ill pick up a can of starting fluid I guess. But hey what are CJ/SCJ gaskets??
What intake did you install?

Brad
Edelbrock performer air gap.
The Performer RPM Air Gap manifold uses the regular port size so standard non-CJ/SCJ gaskets will work.

Don't know who told you $60 for gaskets. Whoever it was lied to you. A set of Edelbrock gaskets will set you back $20-25 from an number of online retailes or $21.99 from Autozone.

Also don't know who told you it was okay to reuse an intake gasket. That's an almost guaranteed leak. Also keep in mind that when checking for leaks with carb cleaner or WD-40, for every place you can reach with the fluid there are an equal number of places under the intake you can't.

New gaskets. Now. Even if it's not the problem now it will be soon.

Brad
The Performer RPM Air Gap manifold uses the regular port size so non-CJ/SCJ gaskets will work.

Don't know who told you $60 for gaskets. Whoever it was lied to you. A set of Edelbrock gaskets will set you back $20-25 from an number of online retailes or $21.99 from Autozone.

Also don't know who told you it was okay to reuse a gasket, especially an intake gasket. That's an almost guaranteed leak. Also keep in mind that when checking for leaks with carb cleaner or WD-40, for every place you can reach with the fluid there are an equal number of places under the intake you can't.

New gaskets. Now. Even if it's not the problem now it will be soon.

Brad
Ok ill try that, And those are the prices from my local auto part store, Ill try napa or fortins, Put in new gaskets. Set air/fuel and time it a tad bit advanced, Then ill let you guys know how it is.
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