Terrible idle and then dead, tought to keep running "FAST EFI"

[Blue85]

I would contact the company and ask them to upgrade the system so that it's designed to be compatible with an automotive electrical system.

Seriously. They need to know that their stuff has issues.

 

[folkenheath]

So what I gather from this thread is that Luke's favorite EFI is FAST, because of their excellent prices and poor ground compatability?

Seriously though, FAST was the first to come out with a self tuning system that works well with high pressure injectors below the throttle blades, most systems will be susceptible to poor grounds, but I am sure some are more sensitive than others. It doesn't have a lot of tuneability or ignition control (the EZ 2.0 is improved), however, that is not what it was designed for, it was designed to be extremely simple but work, and it is. Tuning time spent is literally a couple minutes and it does the rest itself. Now other companies have followed suit and you have more self tuning options.

Ignition control is nice, but it really doesn't give you much benefit when you have to phase the rotor and spend time setting that up. Unless you go DIS like you did, then it's definitely more worth it. But EZ 2.0 has ignition control, and you can add it to the EZ with a $300 MSD box, so it's not really that big of a deal, I can't justfiy spending the $300 on my truck because I already had an MSD box and once the timing curve is adjusted there is no need to touch it anymore.

If you want extreme adjustability then the XFI will leave the factory stuff in the dust. However, these days I would rather have Big Stuff 3 or a Holley Dominator system because they can control DIS coil packs, injectors, and a GM trans all with one computer box. FAST still requires seperate boxes for all of those, so they are in need of an upgrade. But all of those fully programmable systems will leave the factory stuff behind when it comes to racing controls and custom capabilities.

I am sure you got your system working for much cheaper than $2k, I applaud you for that, it's impressive to convert your engine over to DIS. I don't have the patience to build electronics, I would rather spend it fabbing stuff or tuning the engine.

 

[Blue85]

OK, maybe I'm unfair because I spent years in automotive component design. Asking your customer for a direct battery connection is like a joke and would probably get you thrown out of the building. Suppliers even fight over the order ring terminals are stacked on a stud. A factory installed part would be validated at temperature extremes, with lots of various noise thrown in and all the other electronics running. There's about 50 injected noise waveforms injected that can't cause any deviation in performance, not to mention all the RF tests. I understand that the aftermarket can't do full validation like this when they will only sell a few hundred units, but power conditioning and voltage compensation are pretty basic to any automotive EE design.

That small quantity makes FAST users a small community and the company needs feedback on what problems crop up in the field. Otherwise they can't improve since they likely only have a handful of test mules in a handful of configurations. Hopefully there is a clear root cause for what was going on here.

 

[folkenheath]

I'm pretty sure they are aware of the issue, because their latest intructions that came with my friends kit have a paragraph that states (don't quote word for word, but it's pretty accurate), "the power and ground wires need to be hooked DIRECTLY to the battery, do not think you know better and splice it somewere else or it will cause problems".

I have to admit I almost did it myself (spliced them into a solid power and ground junction), but after speaking with one of my EE friends he explained why that was not the same, so I did hook it directly to the battery from teh beginning and I have not had any problems with it.

But to be fair, every aftermarket EFI system I have ever seen had the exact same instructions, hook the main power and ground directly to the battery. So it does not seem to be limited to FAST.

Also, I hear you on the factory stuff. I used to work for Honeywell and we made cam and crank sensors for some of the American vehicle manufactuers (2 of the top 3 automakers). And the amount of testing that those sensors went through was crazy. Made me think I don't ever want to buy an aftermarket part because they can't possibly come even close to the same amount of testing the factory stuff goes through. Chemical dunks, heating and then dunking in saltwater repeatedly, high heat and pressure at the same time, EMI bombardment, almost limitless electrical tests, vehicle testing, etc. I remember doing EMI radiation tests in the lab at one of the customers, and they had a bunch of safety sensors so no one would get trapped in the vehicle chamber when the system turned on. If something wasn't right they could literally shut a car down by generating EMI in the vehicle chamber, if you simply wrapped the offending part in aluminum foil, then the car would continue running and you know what the culprit is. I said, why is it so critical that no one is in there. The guy said, "because the EMI in there could kill you". I said, " so you are saying the vehicle has to continue running past the point that the driver dies from it, isnt that a little overkill?".