It's lean....pure & simple. Richen it up on the secondary jets & see what happens. Street car? I wouldn't use a Holley...not that they're bad carbs, but the E carb seems to really work better for a driver. Might give up a few HP compared to the Holley, but you get it back with driveability and mileage. Been there, done that....had an '84 Mustang that got an honest-to-goodness 38 mpg at one time (yes, it was a mildly built 5.0 with a 5 speed & 3.73's)...with an Edelbrock carb.
Thanks for the suggestion, mavman, it is lean, but not THAT lean. I have richened it up as much as I can by replacing metering rods (but not the jets, there are still two steps up in richness I can go, according to the Edelbrock graph), furthermore, it ran great until just recently, with no modifications made in the fuel/carb/electronics. The secondary flaps just do not open. Has anyone messed with the insides of these carbs, to see how the secondaries are connected to everything else? If not, I have a weekend project. Good thing the local track is still closed...Plus, messing with the carb won't eat into my recently acquired rear spring replacement funds
if you can move the secondaries by the little "counter weight" freely, then it should be working correctly. the secondaries arent technically vacuum, but they open from the engine sucking them open. the tech seems to assume your engine is on.judging by your other posts i think your rod springs are too strong, but im not the master of these things yet either. edit: i mean too soft, the secondaries open the last bit and it goes lean because the rod isnt coming up anymore
Please explain "rod springs are too strong" as I havent messed with anything other than just swapping out the metering rods. I have a couple extra sets of springs that came with the Edelbrock metering kit. If I need to change them, it should be no problem.
the manual that came with the kit probably explains it better, but im thinking that the metering rods are pushed up by the springs as the amount of vacuum decreases the weaker the spring the longer it takes for the rod to rise. your reaching a point where the rears are opening further, but more gas is not coming in at the same pace once you reach that point. if the spring is too soft it wont push the rods up as far so that is when you are "running lean" I could be off on this and a good edelbrock person could probably say this is wrong. sounds like the company tech you spoke too isnt that person though. it could also be that the jets are too lean, but id try the springs first.
The stiffer the springs, the faster the carb transitions from running on the idle circuit to running on the main circuit. Vacuum holds the rods down and when vacuum drops (actually when manifold pressure increases) the rods are forced up by the springs.
Well, I tried the propane test before I read the responses, and it did nothing. I shot the propane straight into the open carb, and you could just barely note an increase in rpms, but if I wasn't shooting it in at the time and expecting an increase, I would have never noticed the change. I will get on the phone with Edel again, and ask about the springs. My kit came with a couple different sets, so maybe one will work with my setup, unless it is just a disconnected linkage somewhere that is preventing the 2ndaries from opening. Hopefully, I will get a more knowledgable person to walk me through it...
you cant tell where its leaking if it is by squirting into the carb. using the WD or brake fluid you spray it where the carb mounts to the manifold and where the manifold meets the heads and listen for any changes in idle while you spray each location. this tells you if its leaking and exactly where.
Naw...I was shooting it into the carb JUST to see if it would raise the rpms. If it didn't make it rev going into the carb, it wouldn't work anywhere else either. I am on hold with Edel right now, waiting for tech to walk me through the opening of the secondaries. IF he says it is working correctly, I have some "gun scrubber" which is basically compressed acetone, which should make it rev nice, plus dry quickly without leaving a greasy residue. Pretty much the same as brake cleaner spray.
OK, secondaries ARE opening, I was unaware that I had to look under the rear weighted flap to see them. Like a couple of you said, the Edelbrock guy agreed to install 8 mm HG springs (silver springs from the set) and remove the stock yellow 4mm springs from under the metering rods. It made a bit of difference, but still does it. I would guess it fixed half the problem. I am not sure now if maybe it isn't a timing issue? It now only does it if over 3000 rpms. If under, it will just accelerate until I hit 3000 then spit and sputter. STill cannot do the leak test...my gun scrubber is "non-flammable", so is ZEP penetrant (mildly flammable), even starting fluid just flooded the motor and killed it???!!!??? I will have to buy some good old fashioned WD-40 and try it later. How can I run a vacuum test on the timing and maybe the carb to test everything is running smoothly?
if the springs fixed it some at the first step i would try the next step up on them and see if that takes it up higher. brake fluid should work as well. it sounds like your still trying to spray it in the carb though? the leak is changed by fluid hitting the vac leak. thats why even water will help you find the leak.
OH!!! I thought we were looking for the rpms to rise when a flammable substance was introduced to the intake! That is why I have been shooting into the carb first, just to find something that will "flare up" the rpms when it gets into the fuel/air mixture. When I found that combustible material, I was then going to shoot it around other areas of potential leak and see where it is being sucked in. If I used a non-flammable liquid, what am I listening for, or am I just looking for bubbles or the liquid being sucked in? AS far as the springs, I installed the stiffest ones that came with my kit. I am starting to think it just might be the vacuum advance/springs and weights on the advance in the distributor. It shows that it advances a bunch (unknown how much until I figure out how much each hash-mark on the balancer is) when I rev it.
sorry i didnt get back to you yesterday (stupid job) the rpm should change when you spray the area that has the leak. as far as the jetting, could you step up the jet and rod combo richer then go to leaner springs? let me know because im still on a learning curve on thos myself.as for the dizzy, i was told to watch the timing with a light when you rev it, it should not advance past the 25 degree mark maximum.
I very much know how old this thread is, but I am having the EXACT same problem and can't figure it out. How did you solve it? Thanks!!
