help setting up carb....???

[ford1386]

i have a 94 ranger i put a 302 in with a holley 670 street avenger and an msd ignition and if the truck sits for a week or so and i go out to start it, it wont start. and i have a hard time getting it to start but if i go out every day it starts right up. and i have a hesitation on throttle opening i've tried changing squirters, changed the power valve, changed jets numerous times nothing is making it better at all. I called mcnew's performance in dillsburg,pa and they said they have a guy they pay to come down from lewistown and he is really good at setting these up........... but they want like $350. I was hoping to find someone that could help me out for less, because its probably something that can be fixed in 10 mins but i dont know that much about carbs..........

 

[kimcrwbr1]

The hard start sounds like the float bowl vent is allways open and the fuel evaporates out of it and also are you sure you have the wet float level correct. I cant help you on the carb but someone here can just hang out and save a bunch of money maybe someone close to you can come over and dial you in.

 

[kimcrwbr1]

Oh yea try blueovaltrucks.com a sister to this forum

 

[cody93]

did u pump the gas pedal a few times before starting it? gas probly evaporated out of the bowl. i know i sound stupid, but hey, just wondering.

 

[originalnitro]

What is your timing set at? Most of the carb problems i've seen is an ignition prob.

 

[Psychopete]

Definitely check you basics, like timing as suggested, fuel pressure, float levels, etc. But if everything were right, seems like your accelerator pump needs some tweaking. Can't just mess with different squriters, you also need to test with different pump cams in different positions since they work together. Check out some of the videos on Holley.com, they are some help.

 

[fordmike1]

i have a 94 ranger i put a 302 in with a holley 670 street avenger and an msd ignition and if the truck sits for a week or so and i go out to start it, it wont start. and i have a hard time getting it to start but if i go out every day it starts right up. and i have a hesitation on throttle opening i've tried changing squirters, changed the power valve, changed jets numerous times nothing is making it better at all. I called mcnew's performance in dillsburg,pa and they said they have a guy they pay to come down from lewistown and he is really good at setting these up........... but they want like $350. I was hoping to find someone that could help me out for less, because its probably something that can be fixed in 10 mins but i dont know that much about carbs..........

Is your accelerator pump leaking fuel? Sounds like it leaks out all of the fuel over time causing it to be hard to start after a week. The hesitation could be from the bad accelerator pump also. Take your aircleaner off and work the throttle as you are looking inside the front two venturi's. You should see gas squirt as soon as you move the accelerator lever. If you dont that could be your hesitation problem and posibley your leak draining the float bowl. Check it out and let us know what you find.

 

[originalnitro]

If you can check vacuum at idle and post reading. Also what discharge nozzle,pump cam,power valve,and jet are you running?

 

[ford1386]

If you can check vacuum at idle and post reading. Also what discharge nozzle,pump cam,power valve,and jet are you running?

18 inches of vacuum at idle so I put a 9.5 inch power valve, stock holley jets 68 in primary. squirter,cam,discharge nozzle is factory holley. I tried different combinations of jets and discharge nozzles but nothing makes it better just worse. But I adjusted the choke spring cap and truck starts right up so that is good prolly just need to adjust it once in the spring and once in the winter but still a hesitation....

 

[fordmike1]

still a hesitation....

You need to check the accelerator pump setting and make sure that is working proper to help the off idle hesitation.

 

[Sasquatch_Ryda]

Personally, I think you have too big of a carb period. People are constantly over carb'ing these engines which will cause a bog/hesitation under acceleration.

A 550-600cfm carb is MORE than enough for a 302.

 

[Will]

A 550-600cfm carb is MORE than enough for a 302.

A small carb is ALWAYS easier to set up than a big one. The fuel metering signal is much stronger on a small carb.

At 5,500rpm and 100% volumetric efficiency a 480cfm carb would be perfect. You don't have 100% ve. After all of those turns and bumps and valves closing a surging the air back and forth you would be lucky to see 80% on a good set of heads at the rpms we really run. A 390cfm would be great on that. A 500cfm AFB would be perfect.

So why is your carb not working well? It's too damn big. Try to blow through a 2' section of 3" pipe and see if you can feel the air on the other end of it. The carb needs to feel ther air. It draws off of air moving through. A carb doesn't force anything--the engine does the work. Does a little 302 move enough air to create a reliable signal in a 670cfm carb?

No.

I'm sure it could be crutched to run okay, but it will never have crisp response and you will not need the secondaries. You need a carb with will have the throttle plates standing wide open at full power. Forget all the homerisms about carbs. You have to drive this on the street. I would find something around 400cfms.

I could get that running, what you have, but it won't run as well as the right carb would.

 

[originalnitro]

I ran a 670 for over a year on my old 306 it ran damn good and got 18-20 mpg. You might want to try my old setup timing was set at 15 degrees, run a 35 discharge nozzle, orange pump cam set in #2 hole,and 70 main jets. Have you checked your timing?

 

[Psychopete]

Have you even tried anything that anyone has suggested? Changing your jets is not going to make a damn bit of difference on your off idle hisitation problem. Squirters work with accelerator pump cams, you need to be tweaking them in both at the same time. Changing either by itself won't get you too far anytime soon.

 

[ford1386]

I ran a 670 for over a year on my old 306 it ran damn good and got 18-20 mpg. You might want to try my old setup timing was set at 15 degrees, run a 35 discharge nozzle, orange pump cam set in #2 hole,and 70 main jets. Have you checked your timing?

My 302 is also bored .030 over but my timing is at 14 degrees now but I was gonna try advancing it a little. If that doesn't work then I'll try ur setup....would it help me at all to change cam positions now?

And on top of that the holley street avenger carb is dry flow tested whereas most carbs are wet flow tested to get their cfm so the holley street avenger 670 is really only a 600cfm