My car has been pissing me off. When I take off and mash the pedal, it bogs down and then takes off. Sometimes it will die instead.
I have checked the carb over as well as I could and it doesn't seem to the problem. I checked manifold vacuum and get a steady reading of about 18. I also pulled the plugs to check them and they are nice and evenly tanned. The only thing that seemed weird was I hooked the vacuum guage up to the vacuum advance and was told that it should read 15-18, I only got about 10. Does anyone have any ideas?

 

The engine is a '92 350 4-bolt, .040-over, flat tops 9.5:1cr, TBI truck heads, performer intake and 600cfm carb, stock GM HEI upgraded with ACCEL parts, 8mm wires, and plugs are AC Delco upped one temp range.

 

The usual reason for a bog and dying is a lean condition. The carb is not feeding enough gas.

Edelbrock sells a jet kit for their carbs, I would recommend that you get one and experiment a bit. The jets are easy to get to in those. Get the kit, take it apart and see what's in tehre, replace them with a couple of sizes larger, and see if it helps. I suspect it will. Odd as it may sound, an excessively lean condition will make the car use too much gas: if you're driving down the road and you're 10% too lean (that is, there's only 90% as much gas per volume of air as what you need) it may make the engine require 20% more mixture to produce the same power, which will result in a net fuel consumption increase of 10%.

The vacuum advance gets ported vacuum, i.e. it comes from a port that is located above the throttle blades, such that there is little or no vacuum there at idle. It should only have vacuum when the throttle is partway open.

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"So many Mustangs, so little time..."

 

ever heard the term quadrabog?

 

Replace your fuel filter first, if you haven't done so for a while. I had the same problem a month ago. I am amazed at how sensitive the Quadra-bog is to less than perfect fuel pressure or volume.

 

Very true Jrr

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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Livin' the Stereotype

 

The carb is an edelbrock 1406, 600cfm w/elec. choke and manual secondaries.

 

Right, contrary to the other posts, not a Q-Jet, it's the Carter AFB with the weight-controlled air valve. Can you say "Stone Age"?

Have you got the jet kit tried some larger primary jets yet? Was it any help?

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"So many Mustangs, so little time..."

 

Quadrajets will do the same thing (experieince with 83Z HO 5.0 liter) when the vacuum pot that holds the top rear plates is bad and the return spring on those top rear plates is broke. If the top rear plates open too soon you get way too much air before you get gas and that sucker will flat die at 50 mph with the pedal to the floor. With the engine idling, those top plates (on a quadrajet 4 brl anyway) should not open when you press on them with your finger. That vacuum pot will hold them shut. Is the edelbrock the same?

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Z's r Best