Quick Holley help needed...

[n737nc]

Got a freshly rebuilt 700DP on my motor tonight.
It starts fine, but will not idle.

As long as you give it gas, it runs fine. But as soon as you try to hold the throttle in one position, it dies.

Anybody have any ideas?

Thanks,
Nick

[bigjimzlll]

check the power valve(replace) make sure your idle adjustment is adjusted far enuff out. The four corner idle adjustments should be around 1 turn out. Open the secondary butterflys a little. Make sure your timing is correct.

[n737nc]

timming is right, I had and Edelbrock on there so it the motor was running.
I played with the idle adjustments, with no luck.
This thing is basically new. I had them replace the power valves.

Even if you try to hold it at 1500rpms, it jumps around and tries to die.

[bigjimzlll]

do you have the vacuum advance hooked back up? To the right port?

[n737nc]

Acually, I tried it on both ports, still the same thing.

[Harold Shepard]

Does it have the "correct" power valve? It should be based on the vaccum of the motor. It has been a while but if the power valve is too weak it will allow the main circuit to come in too early. What type of intake to you have and have you checked around the base plate for vaccum leaks. Check your float levels, the gas should just barely trickle out of the inspection holes on the side. Just some suggestions. Harold

[n737nc]

I don't know if I have the correct power valve or not. This is my first experience with a Holley. I have always been too scared of them. Now I know why.

I can't check for leaks anywhere because I can't keep it running. It dies as soon as I take my foot off of the throttle. As far as a visual inspection, everything looks fine. I also replaced the gasket with a new one after it would not run the first time.

The shop that rebuilt it too all of the specs of my engine, then built the carb. The powervalve in the front is a 30, and the one in the back is a 50. I'm not sure if that is right or not. But, something is not working.

[Harold Shepard]

Holleys are great carbs once you get them right. Check your float levels right off the bat and be sure that the bowls are not too full.... or too low. If this is up to snuff then look and see if gas is trickling down the boosters of the primarys and or the secondaries. It could still be a power valve especially with the 30 up front but it will still run like this. One question did it back fire or pop back when you tried to start the motor? If it did the valve is blown, unless the shop drilled the bleed off hole in the base plate to prevent the power valve blow out. Let me know what you find. Harold

[Harold Shepard]

One other thing, did they say why they used a valve in the back? Generally they place a dummy valve in the back to prevent issues with it. I would question this, also what carb is this? 4150 or 4160?

[n737nc]

No, it didn't backfire.
Thanks for your help. I am going to take a break from it for the night, and try it again tomorrow.

Nick

[n737nc]

Also, it's a 4150

[67shortie]

Hate to question the shop who rebuilt the carb here but I wonder if they used the wrong metering block gaskets? I say this because if the wrong one is used, a passage for the idle circuit will be blocked and the bowl cannot supply fuel to the idle circuit at all=wont idle or run at all until it gets into the main system. But even then you would have to push the engine to get it to run down the road without the idle circuit, this makes for a miserable owner.

Other than that, dirt or debris in the passages, or a float setting way to low/high.