FAST EZ EFI self tuning system issues

I currently have a Borla eight stack with the EZ EFI FAST self tuning system. Idle and acceleration issues developed after a year of running great . I changed the plugs, TPS sensor and IAC and the same issues persist. I contacted FAST and was told they are in the process of discontinuing production of their systems and none are available. I am shit out of luck if my ECU took a dump and forewarning anyone who currently have one or thinking of purchasing one from another source. Any suggestions would be greatly appreciated.

Sorry to hear of your misfortune. An obvious solution is to find a reseller/installer with good depth of experience and have them take a shot at trouble shooting. FAST might be able to direct you to such if you can't find one on your own. Second, that installer may have a back stock of ECUs in case yours does take a dump, assuming your tune can be ported to the replacement. Then of course, there are drag racers who might be changing systems and have an old ECU they are willing to part with for little $.

From memory that system uses a dead head system and pulses the fuel pump to regulate the fuel pressure in the system.

Now if you are running HP pumps direct in your gt40 tanks you are likely to have sucked air and trashed the pumps, Happens in a few seconds when pumping air.

So now possible failing fuel,pump that when pulsing does not get to pressure as the system expects.this in turn would cause the poor running.

Ian

Can you check/access your ECU for error codes?

Once I also had issues with performance.
After changing random parts I purchased the Accel software key etc. to access the ECU > Sure enough I got an error code for no intake air temperature value. Checking the intake air sensor revealed that it was brocken. Changing the IAT sensor fixed all problems.

I’ve had issues from the start with my TBI version of the FAST EZ EFI 2.0 on a 392 crate motor (stroked 351W). Replaced a couple sensors to finally get it to start and idle...still haven’t road tested it more than a few minutes around the neighbor but continually seems to sputter and run rich despite my attempts to reduce A/F ration and the learning mode. I’m almost to the point of throwing a good ole carb on it so it can be more reliable . Unfortunately the pain of all the additional wiring and computer/etc. make it another pain to get rid of it. Needless to say it’s really soured my desire for any future computer assisted builds.

I feel your pain!

Wolfman said:

I’ve had issues from the start with my TBI version of the FAST EZ EFI 2.0 on a 392 crate motor (stroked 351W). Replaced a couple sensors to finally get it to start and idle...still haven’t road tested it more than a few minutes around the neighbor but continually seems to sputter and run rich despite my attempts to reduce A/F ration and the learning mode. I’m almost to the point of throwing a good ole carb on it so it can be more reliable . Unfortunately the pain of all the additional wiring and computer/etc. make it another pain to get rid of it. Needless to say it’s really soured my desire for any future computer assisted builds.

I feel your pain!

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This is certainly very dissapointing for you, but do yourself a favor and get a carb. One of the best moves I made when ordering my car's engine from Roush was to keep the Holley Street Avenger 770 that came with it. The Street Avenger works fine and is cheap and easy to replace if needed, which I have not needed to do. Additionally, I was somewhat leery about having high pressure EFI fuel lines running around this car. Yeah, EFIs make good bragging rights, but I read about technical issues all the time and these cars have enough issues without creating any more.

/s/ Chris Kennedy

Chris Kennedy said:

This is certainly very dissapointing for you, but do yourself a favor and get a carb. One of the best moves I made when ordering my car's engine from Roush was to keep the Holley Street Avenger 770 that came with it. The Street Avenger works fine and is cheap and easy to replace if needed, which I have not needed to do. Additionally, I was somewhat leery about having high pressure EFI fuel lines running around this car. Yeah, EFIs make good bragging rights, but I read about technical issues all the time and these cars have enough issues without creating any more.

/s/ Chris Kennedy

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I was originally going to use a mechanical stack injection on my car but decided that it was another thing with a learning curve that I did not want to tackle. I finally settled on a Proform 850 racing carburetor- mechanical secondaries, no choke, etc. It is essentially a modernized & upgraded Holley 4-barrel. It worked right out of the box on my 383 Donovan running a Crower 00427 cam. The Injection sure wins on looks!

A friend tried a similar setup on his Cobra. After a lot of heartache, he learned the FAST EZ-EFI will not work with the EightStack system. I believe it was that it wouldn't support Alpha-N. Comp/FAST traded out his EZ system for a Sportsman system and issue was partially resolved. (he has a lot of issues with the system but it is finally running)

I'm running a Performance Electronics system on my Borla EightStack and it performs like a champ. Suggest looking to a different ECU

Paul

Wolfman said:

I’ve had issues from the start with my TBI version of the FAST EZ EFI 2.0 on a 392 crate motor (stroked 351W). Replaced a couple sensors to finally get it to start and idle...still haven’t road tested it more than a few minutes around the neighbor but continually seems to sputter and run rich despite my attempts to reduce A/F ration and the learning mode. I’m almost to the point of throwing a good ole carb on it so it can be more reliable . Unfortunately the pain of all the additional wiring and computer/etc. make it another pain to get rid of it. Needless to say it’s really soured my desire for any future computer assisted builds.

I feel your pain!

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I worked off and on over a few months to debug an Easy Fast 2.0 system to work.. No matter what it continually crashed with a Communications Error message on the hand-held unit And it would immediately flood the engine.. Brian Macy et al could do nothing. I insisted that it was a bad ECU. They would not exchange it. $3500 worth of their equipment now sits in a cardboard box waiting for the day when the owner finally gets tired of looking at it and throws it in the trash. Bolted a $300 Holley 670 onto the engine and it’s been flawless for 3+ years now.

George, I also have the Borla Eight-Stack with FAST XFI, XIM and VTC on a Coyote engine. I've had nothing but problems with the system and absolutely no support from FAST. I'm making plans to replace the system with Holley as recommended by Borla and several tuners. You mentioned that FAST plans to discontinue production of their systems - this makes sense especially since they were purchased by Comp Cams/Edelbrock.
I talked to Borla Machine Shop Manager, Chris Roberson, at the SEMA Show last week. He is going to send me the recommended Holley system part numbers for the Borla Eight-Stack.

I have read that older versions (not sure about new ones either) of self learning systems can't cope with hot motors as their lack of vacuum degrades the primary tuning parameter used by these systems.

Kurtiss and Randy I absolutely agree with your assessments, FAST technical support is lousy and their product sold as plug and play is false. They refuse to even check the ECU and see if its the issue. I’m sure someone with skills above mine can make it somehow work. I left a couple of messages for Chris Robertson and waiting for his call. I’m I right to assume that changing the ECU would require a new wiring harness??? I will also look at the Performance Electronic system. A Carburetor definitely makes sense but I like the look of the eight stack and hopefully I can salvage it.

If you're willing to become your own expert, Megasquirt has a great feature in the newer firmware. It's a Speed Density/Alpha N hybrid mode.

When the MAP is below 80%, it runs in speed density, but when the vacuum drops to a level you map, it switches to Alpha N.

I have it on a 383 in a vette with a cheapy chinese speedmaster 8 stack and it runs great.

With the logging, tuning was easy. Megalogger creates a histogram with RPM on the X axis, Vacuum on the Y and the AFR dictates the color. After driving around for 30-40 minutes, it'll color all of the map you use, then process the data into a corrected fuel map. With a couple of itterations of this and extrapolating the missing data, it's pretty well dialed in.

I did modify the manifold by adding 2 separate chambers in the valley. One with large 3/8 tubes to each port and to a Ford solenoid type idle air controller. It gives the added benefit of letting a lot of air bleed from port to port making the sync on the throttles far less critical. The second chamber is with small 3/16 lines for a good MAP signal.

spud said:

.......... hot motors ............

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Hot motors have hot injectors..
Injectors have an impedance. With that impedance taken the ECU calculates the opening times of the injector and so on the fuel delivery to the engine.

When an injector gets hot, its impedance changes (higher) resulting in less opening times and so less fuel but no aftermarked ECU will see that and so on compensate for this.
Thats why EFI always should have a return fuel line, on the other end of the fuel rail, so fuel keeps circulating to the tank and so on cooling the injectors.
Experimenting with raising fuel pressure 14 psi above factory setting will sometimes help also.
Injectors have their capacity numbers given by factory specs at factory pressure settings. If you raise fuel pressure the factory numbers will also raise. So the ECU has to be remapped for that.
Some injector suppliers will have data of their injectors at several pressure settings.

To ad one more important thing.
8 Stack has to be synchronised out of the box with a synchrometer and regularly checked, if one of more is our out of sync it will not forgive and splutter all over and no ECU will compensate.
The same as quad Webers.

The 3/8 copper tube on my setup gives enough air to make the sync not critical.

But you are correct in saying it is critical without this provision. Far more so than with 4 webers because the EFI will dump the same fuel in each cylinder. With 4 webers, 2 may pull harder or less, but they will at least have a consistent AFR. with EFI, the AFR will go all over the place at idle unless the throttles are perfectly synced.

George Cadavid said:

Kurtiss and Randy I absolutely agree with your assessments, FAST technical support is lousy and their product sold as plug and play is false. They refuse to even check the ECU and see if its the issue. I’m sure someone with skills above mine can make it somehow work. I left a couple of messages for Chris Robertson and waiting for his call. I’m I right to assume that changing the ECU would require a new wiring harness??? I will also look at the Performance Electronic system. A Carburetor definitely makes sense but I like the look of the eight stack and hopefully I can salvage it.

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I wouldn’t think you’d need a new wiring harness if they’d exchange your ECU for a good one.
I agree that the 8 stacks look much better on these cars..
This was the throttle-body with internal injectors we have.

Thought I'd throw this option out there. I'm using the Holley HP EFI set-up (installed in 2012). Allows a LOT of configurations (e.g. using the old LS crank sensor with a new cam sensor, which I never thought would work), and after some considerable fiddling, I got it working fine on my home-fabricated 8-stack set-up. Not perfect yet in open loop, but closed loop works fine. Was a big learning curve, 'cause I was in Neil's position on my lack of EFI knowledge. Uses MAP, temperatures, TPS and engine inputs for its metering.

When I was first looking at an engine for my SLC I gave an EFI some thought and made a few calls to Holley among some of the other EFI manufacturers. In general, the sales staff are really not versed well enough to help to any real extent with high compression and big cam engines. So after a lot of phone calls, I finally got an engineer on the phone at Holley by telling them I needed some support on a "NASCAR type race car engine" They had me call back to another number and I talked to someone that knew enough to convince me that he was the best I was going to get on the phone.

The first thing he wanted to know was how much intake manifold vacuum I had at idle. I told him it was around 8-12 inches of vac that jumped around with the big cam. He said right away that any of the self-learning single throttle body type systems like the Sniper or the Atomic will not work and that I need at least the Terminator type but he wasn't sure that would be the best choice, I really should use an individual port injector type system (LIke NASCAR) or either the HP multiport kit or the EFI-R system. He also was very clear that tuning these systems wasn't intended to be done by a first-timer and that I should seek a profession shop with a lot of experience.

The big takeaway is the EFI-R system allows for the very precise mapping needed to replace the wide range of vac signal missing in a radical cam engine, The wide vac range is required to allow the self-learning systems enough variation to derive a fuel map from. That would be something on the order of at least 16-18 inches of vac. 10 just gets you an on-off fuel map that just can't regulate fuel requirements at part throttle or low load power requirements and doesn't work.

That was nearly 10 years ago so maybe the new self-learn systems are better but I believe the low vac signal is still a factor.

Here is what is needed to complete the individual throttle body type system.


That IS a LOT of money. I did a Proform 750. Works well.

Howard Jones said:

When I was first looking at an engine for my SLC I gave an EFI some thought and made a few calls to Holley among some of the other EFI manufacturers. In general, the sales staff are really not versed well enough to help to any real extent with high compression and big cam engines. So after a lot of phone calls, I finally got an engineer on the phone at Holley by telling them I needed some support on a "NASCAR type race car engine" They had me call back to another number and I talked to someone that knew enough to convince me that he was the best I was going to get on the phone.

The first thing he wanted to know was how much intake manifold vacuum I had at idle. When I told him it was around 8-12 inches of vac that jumped around with the big cam. He said right away that any of the self-learning throttle body type systems like the Sniper or the Atomic will not work and that I need at least the Terminator type but he wasn't sure that would be the best choice, I really should use an individual port injector type system (LIke NASCAR) or either the HP multiport kit or the EFI-R system. He also was very clear that tuning these systems wasn't intended to be done by a first-timer and that I should seek a profession shop with a lot of experience.

The big takeaway is the EFI-R system allows for the very precise mapping needed to replace the wide range of vac signal missing in a radical cam engine, The wide vac range is required to allow the self-learning systems enough variation to derive a fuel map from. That would be something on the order of at least 16-18 inches of vac. 10 just gets you an on-off fuel map that just can't regulate fuel requirements at part throttle or low load power requirements and doesn't work.

Here is what is needed to complete the individual throttle body type system.

https://documents.holley.com/199r12258.pdf

That IS a LOT of money. I did a Proform 750. Works well.

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Thanks for the insight Howard. I wish I would have heard info like this from the manufacturer before purchasing and installing. Hard lesson about aftermarket EFI systems but hope others will learn from this too.

Devin