Found a good deal on a Holley Sniper 550-511. Anyone install one of these? Are they worth the work? Where on the tank did you plumb the return line to, did you have to drop the tank completely? Any advice tips or tricks would be appreciated. 1978 with a 383 backed by a 700R4.

 

My advice , keep the carb.

 

Well, the fuel system is easy enough to set-up. But if you decide to do this there will be plenty of help on that.
For now. Consider where the ECU is mounted on the Siper. Any electrical or computer guy or gal will tell you a computer module should never be mounted in a area of high heat and high vibration. No OEM fuel injection system mounts the ECU on top of the engine.
Read all the Sniper and Fitech (similar unit) help forums.
The number 1 problem with these units is ECM failure.
I fuel injected my old girl and truly love the results. But my ECU is NOT mounted anywhere in the engine bay.

 

wat aftermarket system have computer in cabin? 4-vettes wat recomend you?

 

For OP: https://www.corvetteforum.com/forums...level-2-a.html

The biggest cost issue is ECM failure, but it is not the most common. The most common issue is improper installation, followed by a misunderstanding of what "self tuning" really means (Holley hasn't helped this with their marketing). When you start getting into issues with the Sniper itself, the internal fuel pressure regulator and injector wiring are far, far more common issues. After that, you're looking at sensor issues: TPS, CTS, & O2 tend to be most common. After that, ECM failures.

That said, while my Sniper has been problem free thus far, I'd step up to at least the Terminator X line if I were to do it again for the reasons you pointed out.

 

Statistically hard to prove but if I had a dollar for every Cobra guy who switched backed to a carb...I hear frequently ECM failed. Most professionally installed so they say. Not that difficult to install. There is a reason there are good deals on these.

 

Well, perhaps you have your finger on the pulse better than I as to most common issues. I joined a few trouble shooting/tuning sites, pages when I was in the beginning stages of tuning my system in.
What I commonly see, other than poor installation, is a number of people complaining of ECU failure. Often times covered by warranty but none the less removes there car from the road for weeks.
Also the advertising of "self tuning" is greatly misleading. Yes it will dial in the basic fuel map while running. But doesn't learn things like start up fuel, warm up fuel. Tip in, tip out, accerator pump, sensitivity of the accerator pump. And a number of other settings. So yes. Self learning is greatly misleading.
As per which system I run. I run a Summit MAX500. It does not control timing which many believe is the best part of going EFI. I wanted to keep it simple. My timing is controled by a custom curved distributor by DUI. And I'm very happy with that.
Bottom line is that there a number of ways to go EFI with a remote ECU.
Before one just buys the first thing they see. I think it would be important to do a fair bit of research first. Learn about all or at least a few of the other options out there and pros and cons of them. Talk with the guys at your local dyno tuning center. Which system do they have the best success with? As you may need help getting it dialed in. Going with a system the local tuners are familiar with and have success with is a fairly good idea.
Some guys just get used throttle bodies and ECU's from the local salvage yard and bolt em on, wire them up.
Many ways to do this.

 

"Professional" installation just means someone got paid to install it, not that they know what they're doing. Also, when talking Cobras, you're talking about Fords. Fords have the distributor up front, which puts it in the absolute worst place for EMI/RFI issues with the Sniper (which has the ECU on the front of the unit). The ECU likely didn't fail at all, but the owner was never able to fix the EMI issues because of the proximity of the ECU to the distributor. Holley really screwed things up with the EMI hardening of the gen 1 units. Supposedly that is fixed with the new Sniper 2, but the jury is still out on that.


To be clear, I am NOT saying that ECM failures don't happen. They do, for all the reasons you noted. But the simple fact is, most of these things are being installed by people who don't know what they're doing, and the owners don't have the first clue how to troubleshoot problems. I've seen people who can't even take a data log, and aren't willing to learn, trying to troubleshoot problems. Just doesn't work with these things.

 

Thank you all for your responses. And the link from CSIROCZ is very helpful. I will look for more info on this product. Like all things there are those that like them and those that don’t. What would be a good price for a slightly used one with all the wiring, just need a new O2 sensor and O2 bung put in the pipe.

 

After personally installing seven of these......I am going to tell you to take a hard pass.....they work well enough, when they work......a lot of quality problems. Holley has since redesigned the whole thing......so new unit is of unknown quailty.
I also installed the Edelbrock Pro Flo 4 and the MSD Atomic......and I personally like the Atomic better than all of them......
I don't recommend ANY of them without the distributor and timing control.......the EFI alone is not worth the money.......I can do just as well with analog components.....I tried to lock out a HEI and convert it to an adjustable trigger and that was a disaster......

Jebby

 

Thank you for the advice Jebby

 

proflow 4

 

around a grand would be fair depending on the condition. THey can be set up so you dont need a return line. I ran mine without. Go to this website and start asking questions and reading https://www.efisystempro.com/ also start googling or binging "Holley sniper ????" adding in the question you need, somone has solved your issue. I used the Holley youtube videos alot, some very good info in there.

I would spring for the Holley distributor to go with it and have it control your timing. You can use an MSD system but the Holley is alot easier to set up

Once you get it up and running, if you understand basic computer skills you can hook the sniper up to our laptop and build your on fuel map. If not find a local guy to do it. It will run much better than the self learning bit.

Its not a horrible system, but you wont get any miracles either. It can solve hard start issues, it can help with gasoline smells but a properly operating charcoal can will as well. It will not give you any more power than a carburetor or any better gas mileage than a carburetor if that carburetor was properly tuned. I had a Holley quadrajet style carb that I tuned with the Cliff Ruggles book and my 425 hp 327 got 16 mpg. never got better than 12-14 with the EFI after that.

before you buy it price out the intank pump with built in regulator, the fuel filters you require, proper high pressure fuel lines and hose clamps. the O2 sensors, bung installation, make sure the hand held is working, all the relays for the fuel pump and locate a place to install the EFI electronics. I stuffed mine behind the passenger dash pad

 

I picked it up for $500. I figure at that price I could play with it, if I don’t like it I can put the carb back on and at least have new fuel lines. If I do like it I will invest in the ignition system that goes with it. Thank you all for your advice on it. And the links are very helpful.

 

Good deal. tell us how installation is success or not. good luck