Unhappy With Holley Sniper

I purchased a pretty 1972 Grabber Blue Convertible Stang. Purchased through an auction house south of Chicago. Paid way to much for what I got. Thats not the story here. Npv 20 2019 took her to a mechanic friend of mine and is is an excellent certified mechanic. He said he could work on it on weekends. I had saved up and purchased several thousand bucks on parts. The most expensive of such was a Holley Sniper complete kit with distributor wires and linkage everything. The Holley EFI has been difficult at best. A Holley tec said it is wired right.. 361C starts but then stalls.. Holley was kind enough to send him a new ECU. NOW THE cleveland won't even start. Come on Holley let's get it together. I've spent over$2,000.00 on my mechanic on added labor above the quote.. he my mechanic used to have hair.. my next step is to buy a HEI distributor . If that doesn't work. Take it all off. Demand a total refund. And Holly can see me a new carb linkage and mechanical fuel pump for my added cost and trouble. Holley needs to give it up and quit selling EFI kits.

Very happy with mine, but install isn't as easy as they claim in their vids for sure.

I'd really ask your guy to check twice how he has set the IAC and its readings on the handheld, because it gave me too the prob you describe.
No ecu will fix that and it won't run fine till this isn't done correctly.

Okay, I have zero knowledge on these EFI installations. Personally I would not even bother with spending all that money on one unless this was my daily driver or used far more often than most of us are able to. A good carb set up properly might use a bit more fuel for sure, but I could buy a lot of gas for what one of those costs. Then the next thing I see all too often is HEI distributors. Again, my personal opinion and a pet peeve. WHY!! I would look more toward a good DuraSpark set up or a Pertronix II and coil in a stock distributor, curved correctly. You can do this yourself, buying the components, or get a DuraSpark done by a company like Performance Distributors. They build to YOUR engine specifications.

As I stress, this is not an area where I have any experience other than doing my own, but if I can help someone I see wanting to do something I would not do, then my 2 cents worth might be in order. At the end of the day, it's your car, your way. End of debate. 

I have the MSD Atomic, which is now owned by Holley, and will never go back to a carb. The only way I would ever go back is if the power out grows the system. It has made life so much simpler for a car that's driven mostly on weekends with trips throughout the week between home garage and storage garage. Just turn the key on wait a second or two and fire it up. No choke, no pumping of the pedal, etc... I can't speak for the sniper but we have the MSD on our two and three or four friends all have them. Now I have all the parts, new distributor and MSD box, to allow it to control the timing. I have chosen not to make that change for now because I have read so issues with that.  It just runs to good to mess with it at this point. Good luck

Roy, If you ever put all the MSD timing control stuff on please let us know the results. At that point it would be a 50 year old "modern" engine. With the heads you have the torque must be truly impressive. Chuck

@Stanglover "I could buy a lot of gas for what one of those costs."

The maths for fuel over here are 4 to 5 times less optimistic   And aside the money point, I can now for instance stay in garage during a cold start without risking to die within the next 3 minutes! That alone is priceless to me! 

Fabrice said:

@Stanglover "I could buy a lot of gas for what one of those costs."

The maths for fuel over here are 4 to 5 times less optimistic   And aside the money point, I can now for instance stay in garage during a cold start without risking to die within the next 3 minutes! That alone is priceless to me! 

Click to expand...

@Fabrice,  There is no doubt EFI or Throttle Body injection, as it was called back in the late 70's early 80's, has a lot of benefits. I worked on air induction systems for them back then and the testing done proves they are better than carbs. From my point of view, they're just not worth the money for the relatively small gain in convenience and performance. That is just my point of view, no debate.

EFI systems need certain critical  inputs to the ECU and if the system does not have all the information (i.e TPS, 02, timing, etc, etc) it isn't going to cooperate.  Period.

I've been running EFI since 2006 on my 69 vert and the learning curve transition from carburetor to EFI has been a steep climb for my old school knowledge brain.  One of the most important lessons I learned is that out of the box bad components from Holley are rare.  Missed & incorrect connections by the installer probably cause 95% of poor or non-running systems.  Talking to a Holley Tech will not guarantee the system has been installed properly because if the installer says "I did that right", the tech has to accept that as correct, even if it is not.

I've spent far, far, far more than any "savings from efficiency" I might have realized, but I've also gained a new (to me) body of knowledge about EFI as well as  being humbled by things like a simple loose connection that morphed into hundreds of man-hours and $$ until it was found.  The point I'm trying to make is these system do work, but sometimes a complete 'step back / take it apart and start over' approach is needed to find simple little thing(s) that prevented the system from functioning.

" The point I'm trying to make is these system do work, but sometimes a complete 'step back / take it apart and start over' approach is needed to find simple little thing(s) that prevented the system from functioning."  VERY GOOD advice! Chuck

For me, this has been a very informative discussion and how we/I learn. Still not for me with the type and amount of driving I do.

The one issue that has not been addressed is J-Bird's thought on adding an HEI distributor. My comment was to go to a DuraSpark system, but learning as I go, that may not be a sufficient system to be compatible with the EFI. It would seem to me that the MSD would be a better choice. Am I right in the interest of further learning?

Stanglover said:

For me, this has been a very informative discussion and how we/I learn. Still not for me with the type and amount of driving I do.

The one issue that has not been addressed is J-Bird's thought on adding an HEI distributor. My comment was to go to a DuraSpark system, but learning as I go, that may not be a sufficient system to be compatible with the EFI. It would seem to me that the MSD would be a better choice. Am I right in the interest of further learning?

Click to expand...

I can't answer that to be absolutely sure on it. The reason being 3 of the 5 we have installed have 1 mallory distributor with a MSD box, 1 MSD set up on both, 1 69 Camaro with a Chevy distributor with MSD box, and 1 69 Camaro and 57 Chevy with stock distibutor and NO box

None controlling timing

@Stanglover No worries m8, if carb is doing fine and you're happy with it no prob with that! 

I was mainly reacting to J bird's post where Holley gets a bit easy the full load, while it's possible there were some defects, I know by installing one myself that it's a pain to do so on our cars and quite easy to do it wrong despite how they have simplified the process, worse, it can easily be unsafe.

@Bill73Ragtop you told it way better than me!

I've btw used it today and drove 50 kms ( kuz my 73 finally passed the tech control WOOHOOO) and can tell you that this thing rocks!! Still shaking lol 

I went with Aces kill shot ego master kit will update after delivery and install

I have kind of a simplistic, "pragmatic" opinion of retrofitting our cars with aftermarket EFI systems. Simply stated, it's not a necessary modification when looking at the big picture. Sure, I agree EFI can potentially increase your gas mileage, but for the way MOST of the classic car owners really use their vehicles, just how much qas are you really saving driving to the doughnut shop, or local parking lot get together? The savings may add up when spread out over a long period of time, but inconsequential for most owner's minimal driving habits. Did you install EFI for a power increase? Oh yeah, that's why all of the Top Fuel and Funny car teams use Snipers and Fi-Tech, etc, for all the power they add. Willing to put myself in the crosshairs here, because frankly, I don't have the data, I'd like to see real world data on Economy and Power changes using these EFI units on our street cars, the way we really use them. A dyno pull will only show wide open throttle numbers, NOT how any car other than a dedicated drag car, responds. Lastly, and this is purely MY feelings about old cars, and classic cars. I enjoy them for what they are, and also for what they're not. Except for Wintertime, when there may be snow on the roads, I drive mine everyday and it drives fine. I accept the way I have to give the gas pedal a kick to set the choke, give her a few minutes to warm up, driving along it rides precisely like a 1971 Mustang, on a factory designed suspension, engine purring through tuned dual mufflers, steering effortlessly with factory power steering. Not like a NEW car at all! And isn't that the joy of driving an old car? Simpler times. Know that when the day comes that you sell your car , that EFI unit will have been obsolete or replaced with another model, and the next owner will likely take it off and be taxed with procuring the original induction again, assuming many will sell off or trash their carb set-up, fuel lines,, and linkage.
Now, aside from my personal take on things, I will tell you that I do have a name and phone number of a guy who's business is setting up EFI systems and Consulting, if this would be of any assistance to someone. I'll be gone for a week here, but I'll post the information for those interested.

I agree, EFI will not significantly increase horsepower, and the cost per horsepower gained is very high.

This link is for an older Holley carburetor/Holley Terminator EFI dyno comparison on Engine Masters. The carburetor edges out the EFI in their ranking. If you're replacing an existing carburetor for a 12.5 horsepower gain, and the only reason you're doing the swap is for horsepower, the $1,800+ cost for EFI (EFI, tank, fuel pump, fuel lines, etc) is ridiculous. However, newer EFIs can also control timing, which can negate the need for an ignition box, and drivability, as well as easier starting, especially cold starts, have benefits. But, you also have to take into consideration the complexity and troubleshooting and repair of an EFI. It's hard to beat a carburetor and point ignition system for dependability. Anyone that plans on going the EFI route really needs to do a thorough assessment of all of the pros and cons, as well as a risk analysis.

My Edelbrock Pro-Flo 4 on my 427 Windsor was a serious transformation from my original Smeding dyno tuned (witnessed as well as the build) package. Start up, throttle response are spot on. Just moving fuel and air I did not expect more power from the original build. As a daily driver it just works. Also, though not hard core tested but it appears GPM has improved. All in all more than pleased.

Learning to setup and tune a carburetor would solve a lot of problems people have with them.

Sheriff41 said:

Learning to setup and tune a carburetor would solve a lot of problems people have with them.

Click to expand...

I had a Holley on a Camden supercharger 13b rotary in my 79 rx7.

I tuned and tuned on it filling air bleeds with lead and redrilling to get the best results on a specific hill from 20-40mph.

Used an old vbox for info.

Shop I was prototyping for pulled the engine and rented dyno time. In 8 hours the got about 5 hp more than I had tuned.

I can tune a carb. It is just easier for me to plug a computer in and see a datalog/learned fuel and adjust a map. This is especially useful in my engine with the blower. I have it richer at certain areas to keep the blower cool.

Really nice to have my wife drive while I am tuning in the passenger seat to get cruise right where the engine is happy.

Like I said on another thread. You still have to tune EFI. You are just changing the tools you use.

Just to keep Apples to Apples, a side-by-side comparison on a 351c , which hadn't been designed for EFI, rather than an LS, and figuring in the added complexity of hook-up in the car on their 1 thru 10 scale, rather than on a dyno stand would have been a more realistic overall comparison for Mustang owners don't you think? Anyway, I am not sold.