hi guys!
I have bought a Ford Crown Victoria '86 5.8L Do you have any idea where I can get some information how to tune the carb? The plugs get Carbon Fouled
Peter POLAND
PS This is my wife's comp. so for the while my nick is going to be sylvia.
First, get a very inexpensive code scanner to help guide you - the small ones for EEC-III will also scan your MCU system.
From:
Other computer-controlled carburetors have a stepper motor that controls the air flow past a tapered valve on the motor stem into the main system. This stepper motor is popular on some variable venturi carburetors .
The stepper motor has four field windings, and the travel on the motor stem and valve depends on which field winding the computer grounds. As the computer grounds the various field windings, the motor stem and valve move horizontally in steps with a maximum travel of 0.400 in (1.01 cm).
A lean O2 sensor signal causes the computer to move the stepper motor stem and valve inward to close off some air flow to provide a richer air-fuel ratio. If the O2 sensor indicates a rich air-fuel ratio, the computer moves the stepper motor stem outward and allows more air flow into the main system to make the air-fuel ratio leaner. Since a certain amount of fuel is moving through the main system with the engine idling on a Ford variable venturi carburetor, the stepper motor controls air flow only into the main system.
This should point you in the right direction, anyway.
Rob
ALSO: the common failure: from:
Its main weakness is that big vacuum diaphragm, which tends to rupture. That results in ultra-rich running, a fouled O2 sensor, and perhaps even an over-filled crankcase from gasoline dilution. An approved modification that'll make the diaphragm last longer is to drill a drain hole in the bottom of the cavity 1/8 in from the gasket surface with a #46 (.081 in.) bit. This eliminates the nasty fluids that eat up the rubber.
Another common problem with the 7200 version is a jammed stepper motor that won't respond to computer commands. You may be able to free it up with electrical contact cleaner.
An R&D engineer at a company that makes carburetor repair components gave me a good tip: "When you pull the top off a VV, don't disassemble it and throw it into the solvent. Instead, use spray cleaner so you don't have to remove the enrichment rod levers, etc. That way, there'll be much less to adjust." Actually, the idea of doing no more disassembly than necessary can be applied to any carb.
Rob
PS... the police 5.8 had the VV carb through 1991...
Thank you Rob. This is surely helpful since I've just got rid of that stepper motor thinking it was the choke :-) Haven't looked at the plugs since. Hope it is some solution until I get the stepper motor running correctly.
The point is that I had the carb rebuilt (using the kit) and it looks pretty now. I had the stepper motor checked and it should run fine BUT it doesn't. It might be the computer steering it causing problems or the O2 sensor.
Another thing that comes to my mind is the float level. Do you think it might be too high?
Thank you for your opinions as it it virtually impossible to get any constructive help from any wrench down here.
Peter
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