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Senior Charter Member
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Discussion Starter · #1 ·
Curious if anyone else has the FAST EZ-EFI and if your having the same trouble as I am? Initially I thought it was a great upgrade but I have been having a continual intermittent problem of either the idle changing or it falls flat on its face and dies at stop signs. I have called FAST for help and they thought first I didn't have the butterflys set up properly but I did their setup and the problem persisted. Then they thought it was the IAC but refused to send me a replacement. I bought my own for $85 and the problem is still there.

My IAC is at around 16 at a 1% TPS which is what FAST told me it should be. The handheld will show the same numbers when the idle changes (2500RPM VS 800 rpm). I noticed if it idles fast, I can reset it by shutting down and restarting but I can't figure out the stumbling problem. When it kills at a stop, it won't start unless I floor it while cranking.

Any thoughts would be appreciated, especially if you solved a similar issue with one of these.

Thanks
Jerry
 

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you might PM Karen (VNMSSS) on the coupe forum. I believe she is racing her coupe with that set-up, and is pretty tied into their tech department.

Rob
 

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section 8
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yep sounds like too much fuel . Since its efi rich is lean . Computer adding fuel to compensate for lean. This is too simple but triple check for vacuum leaks . Not real familiar with Fast but if it's the same as most , check the fuel pressure as stated above if it's constant then the trouble is with the air (maf,tubing, vac leak etc) or the control bits (map/temp sensor etc) . Bob
 

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PM Sent

As others have noted here......First suspiscion would be a vacuum/manifold leak, but with that eliminated, IAC/TPS and/or some kind of base table miscue would be the next place to look. Long PM sent, along with name of FAST tech to contact......

Wayne Presely, Dave Borden, John Card, and many others here have probably fogotten more about tuning EFI systems than I'll ever know....Hoping they'll weigh in, as they are wizzards at this stuff....Good luck and hang in there, help is on the way....

K
 

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Discussion Starter · #6 ·
I got it!

well as others have said, it was definately running rich. I read up in the instructions and got back in the car and went for a long ride with many stops to adjust the handheld. As I watched the Actual AF against the Target AF I noticed the idle fuel was rich so I leaned that out a bit. The stumbling still persisted so I checked the Accel Fuel which was at 0. This really threw me off at first because the instructions don't give you the span for any of the adjustments which is a real negative of the manual in my mind. It was by total frustration that I pressed the down arrow, not expecting anything less than 0 when it went negative! A simple adjustment to -2 fixed 90% of the stumble and I settled in for now at -3 and it has not stumbled once. I don't know what the span is but 0 is not 0! The idle never went nuts so I'm crossing my fingers the computer was just trying to burn all that extra fuel when that problem happened and that I fixed it now.

I know a lot of guys are considering the system and I feel I need to give it a fair review after all I have gone through, so here I go... Ease of installation is definately there. Ease of adjustments is also a plus. The best way I can describe my experience is that the advertising is misleading. Before I purchased the system I had watched a video they put out where a 10 year old did the initial setup. Furthermore, you are lead to believe the adaptive learning will take care of everything from there. This was reinforced by an episode of two guys garage where they did several dyno runs and it put out better HP each time. I would have been much better served if they had produced a video which describes how to fine tune the system and better yet, explain the limitations of the adaptive feature. Now that I understand this better and I no longer am afraid of messing up the "smart" computer. I honestly thought the advanced options were for racers and for pleasure driving you wouldn't need to go into them but I was wrong for my engine at least. As a result I was convinced there had to be a problem with a sensor or the computer. I'd buy it again but my expectations would be different now. Plug and play??? In my case not really. Easy to tune with a little understanding? Yes. In my opinion the manual could be written better to include spans, default points, and expand the troubleshooting section to include drivability issues like what I had instead of obvious installation errors. Hope this helps someone else in a similar situation.

Jerry
 

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Discussion Starter · #8 ·
Interesting. This is what I found:

Quote from above article- Since the 240SX is a light car with a big engine, it requires very little gas pedal effort to get the car rolling. During these light throttle situations, we noticed the engine wanted to run rich and bog momentarily. An “accel fuel” option you can adjust in the ECU works just like a carburetor accelerator pump, and by pulling a few percent out, were able to make the vehicle run perfectly under those light throttle transitions.

Seems a correction chart for displacement vs weight would be handy. I can give one data point for the chart... 302" displacement installed in a roadster = -3 on the Accel Fuel setting.

Jerry
 

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What else do you need to convert to this EFI system?

I see Summit Racing has the kit for about $1700.

I have a 347 with Vic Jr heads and Vic Jr intake now.

I'm assuming I would need to go to an EFI fuel pump. I have the Aeromotive SS carb pump now. It's noisy.
 

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section 8
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All I know is 10 year old probably can tune it 10 minutes, getting technologically challenged in my old age . Plus they keep making the dang buttons smaller !! Glad you fixed it and quick too .Bob
 

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Discussion Starter · #11 ·
What else do you need to convert to this EFI system?

I see Summit Racing has the kit for about $1700.

I have a 347 with Vic Jr heads and Vic Jr intake now.

I'm assuming I would need to go to an EFI fuel pump. I have the Aeromotive SS carb pump now. It's noisy.
They have 2 options. The first is without fuel pump, the second is with the pump. I'm not sure if the latter has a regulator or not. I purchased mine for around $1550 without the pump or regulator. You need a pump capable of 43psi and a regulator with a vacumm port and a return bypass. I'm using a stock mustang pump and a Mallory regulator.

There are a few options out there, be sure to look into each of them to be sure you select the best system for your engine. I have a few regrets in hindsight but now that I have it tuned I'm happy for now. Time will tell.

Jerry
 

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Jerry,

What would you do differently?


****
 

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Can you elaborate on the regrets?

Thanks,
Tommy

I have a few regrets in hindsight but now that I have it tuned I'm happy for now. Time will tell.

Jerry
 

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Charter Member
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What else do you need to convert to this EFI system?

I see Summit Racing has the kit for about $1700.

I have a 347 with Vic Jr heads and Vic Jr intake now.

I'm assuming I would need to go to an EFI fuel pump. I have the Aeromotive SS carb pump now. It's noisy.
Michael,

I have the same heads and intake on my 331. I am going with this in the next upgrade. The only thing you will need is a fuel pressure regualator for EFI and weld an O2 bung into the headers. I am running the Aeromotive A1000 pump with the A1000 carbed bypass regulator. I just need to switch to the A1000-6 injected bypass regulator.

Atlantic Speed has it for the same price, although I have seen it on sale in the $1599 range. They also have free shipping.

http://www.atlanticspeed.com/productcart/pc/viewPrd.asp?idproduct=6175&idcategory=172

Rob
 

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Discussion Starter · #15 ·
Jerry,

What would you do differently?


****
I guess my biggest regret and what I would do differently is that I probably would have kept it carbed and spent the money on a set of jets, springs, etc., and just learned to better tune the carburator or maybe just purchase a better carb. I was running a Holley Street Advenger and it had some choke and hesitation issues but nothing that couldn't have been worked out.

The system installs easily but to be honest, I spent quite a bit of time getting all the wires spliced in nicely and when you look at the money I spent, I would have been able to have purchased 3 carbs! I was suckered into believing you just bolt the system on and it self tunes itself but that is obviously not what happened in my case.

I suppose in the end it is all good but I've been annoyed with it for the past 3 months and my perception of the cars reliability has been tainted. It will need to win back my trust for sure.

Jerry
 

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Having problems with Fast EZ-EFI

I've read through the other posts concerning problems with the EZ-EFI. I have a roadster with a Ford SB 347 stroker, cam is fairly wild. I just installed the master system and it runs great except for idle. I've been through the calibration procedures a dozen times and have even experimented with the 500 c.i. and over settings trying to eliminate my idle problems. Like others I've read about, sometimes it idles ok and other times it will stall out when coming to a stop. I have a pcv valve, so I'm going to plug that vacuum port and see if it make any difference. If anyone has experience with this issue and has a solution, I would much appreciate haring about it.
 

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It sounds like you are having issues with the IAC motor. I have had issues with those in the past.
 

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well as others have said, it was definately running rich. I read up in the instructions and got back in the car and went for a long ride with many stops to adjust the handheld. As I watched the Actual AF against the Target AF I noticed the idle fuel was rich so I leaned that out a bit. The stumbling still persisted so I checked the Accel Fuel which was at 0. This really threw me off at first because the instructions don't give you the span for any of the adjustments which is a real negative of the manual in my mind. It was by total frustration that I pressed the down arrow, not expecting anything less than 0 when it went negative! A simple adjustment to -2 fixed 90% of the stumble and I settled in for now at -3 and it has not stumbled once. I don't know what the span is but 0 is not 0! The idle never went nuts so I'm crossing my fingers the computer was just trying to burn all that extra fuel when that problem happened and that I fixed it now.

I know a lot of guys are considering the system and I feel I need to give it a fair review after all I have gone through, so here I go... Ease of installation is definately there. Ease of adjustments is also a plus. The best way I can describe my experience is that the advertising is misleading. Before I purchased the system I had watched a video they put out where a 10 year old did the initial setup. Furthermore, you are lead to believe the adaptive learning will take care of everything from there. This was reinforced by an episode of two guys garage where they did several dyno runs and it put out better HP each time. I would have been much better served if they had produced a video which describes how to fine tune the system and better yet, explain the limitations of the adaptive feature. Now that I understand this better and I no longer am afraid of messing up the "smart" computer. I honestly thought the advanced options were for racers and for pleasure driving you wouldn't need to go into them but I was wrong for my engine at least. As a result I was convinced there had to be a problem with a sensor or the computer. I'd buy it again but my expectations would be different now. Plug and play??? In my case not really. Easy to tune with a little understanding? Yes. In my opinion the manual could be written better to include spans, default points, and expand the troubleshooting section to include drivability issues like what I had instead of obvious installation errors. Hope this helps someone else in a similar situation.

Jerry
Hi, I have a Fast efi 2.0 for my ford motorsport 302, 345 hp. After considerable tuning I have set the idle at 14.4, cruise at 14.7 and WOT at 14.0, accel fuel to -7. Ignition 20 up to 35, load 70->wot. It runs very good at load up to 70 at any rpm, and it is learning. However at wot it gets to much fuel, and hesitates a little, so I my tactics are to lean out the wot until it starts learning and then back it down slowly to 13.4.
 

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I have a friend that can't quite get his tuned in either. He has also had drop back to idle stalling.
 

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I have a friend that can't quite get his tuned in either. He has also had drop back to idle stalling.
I run a FAST EZ system. Had this same problem which on the screen showed it going lean as it dropped back to idle. Dropping a couple of points in the AF ratio for cruise mapping took care of it. Something simple to try.

Geoff
 
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