670 Street Avenger on ZZ4 - a few problems
 

Hi All,
I just bought a new 670 street avenger w/ electric choke for my ZZ4. At first I thought i was in business but I am now having a few problems and I wonder if these are common and if fixes are known:

1) I can't get the fast idle cam to move freely. When I start the car the chokes kicks on and the choke plate comes back off in time as it should. However, the fast idle cam never moves past the middle position causing a 1500 rpm idle. I can force it down with my finger and idle drops to about 700 rpm but as soon as I kick the throttle even the slightest bit it moves back to the middle position and sticks there. I have tried turning the choke housing both directions in hopes it might free up, no luck. Am I missing something?

2) I opened the throttle all the way to check the fast idle screw and noted that it comes in contact with a delete plate on my intake manifold. As I understand it these are the carburetors offered on the ZZ4 from the Summit if ordered fully dressed so I don't think this is right either. I would estimate I am getting 90%+ towards WOT before it hits. Could this be the problem? I am having a hard time thinking it is because the fast idle cam sticks if I just flick the throttle the slightest amount. In that scenario the fast idle screw is no where near bottoming out on the obstruction. I could potentially solve the clearance issue by screwing the fast idle screw in some or by adding a 1/2" spacer between the carb and the intake. Has anyone seen this before? Solved it?

I did run a new 12V source just in case. It is good and so is the ground.

I'm on the verge of sending the carb back for another, any input would be helpful.

Thanks,
Dan

With a new carb the part should move freely without bind. I would send it back and get another. SA's have troubles with tolerances in manufacturing and some need adjustment to function mechanically. Brand new, get another

I have no answers, but I know what kind of heck the SA is putting you through.

I could never get my SA working right. I took it off and replaced it with an Ultra Double Pumper which worked great right out of the box.

Good luck! :cheers:

As long as you are messing with the SA, pull it and set it on a stand. Ck the choke plate tied to the choke housing has free movement. Ck the fast idle cam and screw and linkage to the choke for free movement. Make sure the choke is set in the middle. If all of these move free there is not reason for it hang up unless when on the engine some of the linkage is catching on something around the mount. Go through the adjustments in the Holley manual for fast idle, choke plate break gap and the rich/lean settings.

Last slowly open the throttle and manually move the secondary butterfly to make sure they open and close freely. I have seen several of these come from the factory with the butterfly's having burrs on them preventing them from shutting fully.

Thanks for the advice so far. I'm not opposed to sending it back and even swapping it for something else. My last SA wasn't working right and I finally got sick of messing with it so i replaced it. I need vacuum secondaries for the TH400 that I have in there right now. Recommendations welcome.

Shame, too. It really runs great with this new one on there except for the problems presented above. I think I'll try a few of the suggestions here and then call Scooter at Summit and send it back if it isn't perfect.

Your mentioned that if you move the fast idle cam with your finger that the motor will slow to idle but as soon as you blip the throttle it will go back to fast idle. This don't sound like a sticking fast idle cam, if it were sticking it would not return to fast idle.

Neal

I stand corrected. I see that the tab with the rectangular slot in the top moves with the primary throttle shaft. Still don't understand where/how the adjustment is made

Fast idle speed is set by sticking a screwdriver in the slot and bending the tang. The choke duration is set by rotating the choke housing. The SA carbs are not set up correctly out of the box, and require setup and adjustments to run right. I've been receiving quite a few of them for test and "new carb setup" from people. Once set up correctly, they run reasonably well.

Lars

Got it. thanks...moved the tab. will check out how it does later today

TC

This is true....but I will add that I have NEVER seen a Street Avenger not need to be jetted out of the box........floats adjusted, vac sec spring swapped out......
To me they are a miserable carb and although can be made to work well.....why?
Send it back and get a Crate Motor carb from Pro-Systems or AED......
BTW....your choke is set too far favoring the closed position......open it up some and the cam will drop right out when it heats up.
Personally.....I would put a 770 TRUCK Avenger on this......single feed, billet boosters, secondary metering block.....a Great Unit for engines under 400 horsepower.


Jebby

I'm confused This thread started in 2014 concerning a 670 Street Avenger. Yesterday this user Tcheairs38655 posted onto this thread but he has a C2 with a Holley 3247 and his thread is in the C2 forum see below
https://www.corvetteforum.com/forums...ey-3247-a.html

I keep getting responses to this Street Avenger post I guess because it's somewhat related, but I don't know how to opt out of it. I guess I'll have to opt out of the Holley 3247 thread I posted. How does one opt out of "related" threads?

Sorry...Tcheairs

Ha....I got snafu'd because I did not look at the date of the thread!!!!:hide::leaving:

Jebby

What's happening a lot on the Forum now is that they have added that "Related Threads" feature at the bottom of every thread. If you're reading a thread and choose to respond, you have to be very careful about scrolling down for your response... if you scroll all the way down to the bottom of the thread, you're actually in the "Related Thread" section, and you unintentionally will be posting in an old, unrelated thread that you never intended to participate in, making you look like you're reviving an old topic with a comment that is completely irrelevant... I've done it myself several times already, and it makes you look like an idiot... (I'm guilty). I then quickly delete my unintentional post in the wrong thread to try to avoid looking like a fool.... a tough task for me.

Lars

Click your screen name in top right corner then click 'control panel' From there click 'settings and options' then 'edit options'. From there scroll down and select/deselect 'default thread subscription mode' (this will or wont notify you of posts in a thread you subscribed to. From there scroll down more to disable 'show similar threads'