Biochem

I did the Ed Maher list of mods a while ago (they work great). One was to loosen the AV tension to 1/4 turn past zero (I think that is right). The only mistake I found in his article was that he said it was a 5/16" wrench, but mine was only a 3/16"... Bad ED!

Anyways, I am wondering what the signs are if the tension is now at zero. Will it bog when you hit the gas? Will it do so in park too, or only in drive? I am just wondering if my spring is wearing out and 1/4 turn of a year ago is now equal to no turn at all...

------------------
1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock... all the suspension stuff... 9-bolt posi disk is in... K&N filter... 93 octane...

I got the GO... I need the SHOW... Interior is next!

Ed Maher

If you don't have a bog then you are fine (the only purpose of the spring is to band-aid the opening of the AV to prevent a bog.) i don't think the spring is going to wear out, at least not a lot.
About the size...oops. Maybe there are different sizes in different years. Like i said in the article, some qjets have torx set screws, a real pita to get to.
...ed

Biochem

Well, my problem is only when the engine is cold. It starts up fine, but then I get a few blocks down the road and it wants to stall and hitting the gas it wheezes and then kicks in and goes.

When I hit the peddle, I think I can hear the gas shoot in, but it is like there is no vacuum pulling it in. I just can't figure it out.

novadude

Secondary air valve tension only comes into play at over half throttle. It has no effect on light throttle operation. Heavy throttle on a cold carbed engine will always result in a bog... no way around it.

Ed Maher

Right on novadude. Think of that bog when cold as your engine yelling at you for trying to beat on it before it is ready.
If it's really bad, you might need to do a couple things. You might need to adjust the choke a little tighter. It also could be related to general tune-up issues like plugs/wires/cap&rotor/timing. Also, a bad/maladjusted TPS can give you a stutter.
...ed

MRZ28HO

Well, if you hook up a vacuum gauge you'll see that there is no (or loss of) vacuum when you go WOT initially. After vacuum starts to "acumulate" then the secondaries work. Hence what novadude said.

As for hessitation, are you letting the engine fully warm? If so, do as Ed said.

------------------
George P. Lara
1994 Z28 LT1 T56
1984 Z28 High Output
Member: SCCA, SCFB, SC3GFB

Biochem

No, this is a bit more then just the carb not being warm enough. It has progressively gotten worse over the past few weeks. I sprayed some carb cleaner in there the other day, and it helped, but it is still wrong. If I sit at a lite and try to go, it wants to wheeze and cough. Even when I am going 45mph and not hitting the gas, it sometimes stalls.

Do I need a special tool to adjust the TPS or just a voltmeter? I am to the point where I am going with a non-ecu carb anyways, but I need this thing to run for a few more months. I will check the plugs this weekend.

Timing is at 8 and the wires/cap etc had no effect. I re-adjusted the choke over the weekend, but nada. Would a mal-adjusted TPS get better when the car warms up?