Fast Ez Efi Throttle Body Fuel Injection System Reviews
I recently bought an EZ-EFI throttle torso fuel injection arrangement from FAST for my '70 Buick Skylark. I installed information technology according to the instructions and it started and ran pretty good for the kickoff few days. I've noticed at present that the engine runs very rich and it's starting to load up the spark plugs. I've not changed whatsoever of the settings withal it runs a lot richer than before. My idle air-fuel ratio is 13.0, the prowl setting is xiii.five, and wide open throttle is 12.5. I don't understand why the engine seems to run much richer than these settings. Y'all have whatever ideas?
H.L.
This is an EZ-EFI throttle body on a large-block Chevy we did a couple of years ago that worked out very well. Attending to the details will make a big difference in how the system works.
Jeff Smith: We've installed several of these new-generation, self-learning fuel injection systems and they seem to work very well. But there are a couple of areas where it is essential that the initial installation be performed properly and then attention to details can make all the difference. Allow's run into if we can focus in on your problem.
The first thing to emphasize is that the main power and ground wires are in fact connected straight to the battery. All EFI systems operate on electrical signals from sensors that normally operate on a 0-five-volt scale. This leaves very little room for error with regard to proper grounds. Then information technology is essential that the primary power and ground leads get directly to the battery. This allows the battery as well to operate like a giant voltage spike suppressor which allows the electronic side of the arrangement to operate unremarkably. Don't be afraid to lengthen either or both power and basis leads if that what it takes to plumb them directly to the bombardment.
The next item to effort is to run dorsum through the initial calibration process again. This essentially purges the calculator'southward memory of the previous tuning changes. This ways starting with engine deportation, idle rpm, rev limit, fuel pressure, and resetting the throttle position sensor (TPS) calibration. Then set your idle, cruise, and WOT settings the same every bit before. Once all this is complete, the engine should run equally it did when you first installed the organisation. Drive the car for a couple of days and make sure to shut the engine off and restart it several times during the examination. Yous may notice that the engine begins to run rich once more after several cycles of running and then shutting the engine off. If the over-rich condition returns, I call back what y'all may be experiencing is a very mutual trouble where there is a leak in the exhaust system that is causing the over-rich air-fuel ratio trouble.
If you've ever driven a car with an exhaust leak, y'all can oft hear a very audible tick-tick-tick from the exhaust. The tick you hear is the result of an exhaust pressure spike that travels downwardly the exhaust pipage, finally exiting later the muffler. When that pressure spike hits the atmosphere, it sends a reverse or low-force per unit area pulse support the pipe and back to the engine. This low-force per unit area spike volition pull in exterior air every bit information technology passes through the leak area. Think of it similar a siphon pulling fresh air in from the outside. Unfortunately, this tin crusade problems with a self-learning EFI organization.
All of the self-adapting EFI systems use a wide-band oxygen sensor placed roughly at the header collector, downstream in the exhaust system. The sensor reads the exhaust gas and the engine command unit – the computer (ECU) uses the information as feedback to the melody. Equally their name implies, these wide-ring sensors (WBOS) operate over a much wider surface area of air-fuel ratio from very rich at 10:i to very lean at xx:i. All WBOS operate the same way. They do non actually mensurate the ratio of air to fuel. Instead, they are calibrated to sense the corporeality of costless oxygen in the exhaust system. The ideally-balanced chemical air and fuel ratio for whatsoever fuel is called the stoichiometric ratio. For gasoline, this ratio is 14.7:1. With lean air-fuel ratios such as 15.8:1, in that location is more free oxygen in the exhaust because there is minimal fuel to consummate combustion. This is called an excess-air ratio. An air-fuel ratio of 12:ane for instance would be considered an excess-fuel ratio and comprise very little free oxygen considering there is more than fuel available to apply more than air to combust the fuel.
The reason it's of import to know how a WBOS works is because in that location are several conditions that tin can fool an oxygen sensor into thinking that the engine is running lean. The first state of affairs is actual misfire. Oft, an engine might create a misfire that you may non necessarily feel as a hesitation. This happens quite often under high load at WOT. When this misfire occurs, that unburned fuel and gratuitous oxygen travel out the frazzle where the WBOS reads the free oxygen. This is then interpreted that the engine is running too lean and needs more fuel.
If, as may be the case with your car, you lot either have an engine misfire or – more than likely – a leak in the exhaust system, this higher oxygen content in the exhaust volition rapidly fool the WBOS into reporting to the ECU that the engine is running lean. This adds fuel to the engine. What makes matters worse is that well-nigh (if not all) self-learning EFI systems store the new air-fuel ratio tune to the ECU when the engine is shut down. Then the procedure starts all over again because the leak in the exhaust system is still fooling the WBOS, each time the engine is operated and and then close downwards, the new, richer cocky-learning table is added to the existing tune. This is the downwardly spiral that makes the engine run richer every time it is started and run.
Then it could exist the solution to your problem is to bank check the exhaust organization very carefully. Two logical places for air to enter the frazzle system is the gasket betwixt the header and the head and the other at the collector flange where there is oft a gasket that tin can easily allow fresh air into the exhaust. This tin occur even if there is no aural tick or leak in the system. If the header gasket shows black frazzle tracks past the gasket, it'southward likely that it is besides allowing exterior air into the frazzle. Another possible leak path is the WBOS mounting bung itself. Brand sure that this plumbing equipment is fully welded into place with no pinholes that could allow air very well-nigh the WBOS itself. Some other possible leak path could be whatsoever identify where two exhaust pipes are welded together. This is a very common identify for leaks to occur. Look for these holes at the top of the pipe where it is most hard to weld when the pipes are in the car.
A great style to bank check for exhaust leaks is to pump smoke into the system. There are several commercial fume generators on the market designed for this kind of testing, only we have too seen some ingenious home-built fume leak detectors built with liter soda bottles that can do the job. Eliminating even a very small-scale leak or crack in an exhaust system will brand a huge difference in improving the performance of your fuel injection organization.
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Source: https://www.onallcylinders.com/2016/03/11/ask-away-jeff-smith-troubleshooting-tuning-fast-ez-efi-fuel-injection-system/