I Finally Did It.....EFI

[rmchrgr]

Here is a fuel graph after adding learn table and some smoothing.
View attachment 1060875

Been a while, bringing this back up. Any updates 3 Wood?

So, my fuel graph looks fairly similar to yours.

It's taken me a while to get to this point but I'm finally understanding what needs to happen with this Sniper thing. Building a config file was what really got me to this point and how it all started coming together. You really do have to put the time into it.

Looking at your fuel graph from way back in January, it looks like we both have a similar spot around 3,500 rpm and little vacuum. I have a theory about it because it's been difficult to tune it out. Since mine is a 4 speed, I believe it's from winding the car out in gear and then letting off the gas to shift. (no, I'm not power shifting) The inertia of the flywheel keeps the engine at close to where the rpm was when you let off the pedal so it's seeing 3,500 but since your foot comes off the throttle there is no TPS input at that instant and the ECU adds fuel to compensate to be safe. Not sure if there is anything I can do about it unless I do start power shifting!

My learn table is pretty decent right now except for that blue spot which is the same as the purple area in the fuel graph. Might be able to reduce the compensation values soon.

As far as driving experience with the Sniper - overall, it's been good. I'll admit that since I've been driving it regularly this summer I've been towed home twice but neither time was the Sniper's fault. First time was a wiring issue. The main ground wire for the ignition box came out of the back of the connector and caused the ignition to shut off and it wouldn't restart. I didn't figure it out until I got it home but there was no way I was going to diagnose that on the side of the road. Up until that point the car was running great. I built the harness myself so clearly I didn't do the best job crimping. Nothing I can really blame on Holley except for having to re-do their entire harness because none of it worked for my application.

Second time was because I ran out of gas. I had installed a new digital fuel level gauge and was certain it was reading correctly. Found out the hard way it wasn't when the engine just shut off going up a hill on a parkway. Not fun! I could hear the fuel pump screaming right before it shut off but by the time I realized what I was hearing it was too late. Again, not the fault of the Sniper but my own wayward hands.

One issue I have had with it though is the dreaded emi. EMI/RFI does not prevent the car from running and it's effect is subtle but it's there. You can see it in the data log trace because it drops out every so often for around 6/10 of a second. (yes, 6/10) I believed the source of it was the coil wire and it's proximity to the alternator. My coil is on the inner fender and the wire goes over the alternator to reach it. When I went to see if I could find anything obvious, I noticed the coil wire laying on the alternator case. I kind of re-routed it away from contacting the case and the data trace cleaned up. Doh!

Unfortunately it seems to be an intermittent problem because on two recent back-to back data logs one is clean and the other still shows it. Might be a little harder to pin down than I thought. I think the main concern is that the data is corrupt and the ECU compensates for it one way or another, like with spikes of fuel or wacky AFR readings. The car runs smoother when it's clear but it's barely noticeable. Have to look at the log file to be sure and use the "mark data points" feature which visually plots the traces.

How's your EFI experience going threewood?

 

[threewood]

No issues at all. But with the heat and lack of A/C I'm not driving it as much as I had been. I haven't played with the programming since the last post on here. It seems to be in a good spot.

I did have to replace a plug wire on #7 that was burnt through which was probably the cause of the fuzzy a/f trace. Definitely runs better.

As for your interference, I wonder if power wires too close to signal wires could be an issue. I don't know much about it but @Billccm brought it up a few pages back. He may have more insight than I would.

 

[BubbaMope]

I finally gave in to the dark side. Purchased a Holley Sniper EFI for my GTX. I've been having a weird lean pop at mid-low rpm that I just cannot tune out on my Edelbrock AVS carb. Said "F' it and bought it.

I already have the Holley Sniper EFI gas tank with 255 Walbro pump and an o2 sensor installed so it should make for an easy swap. I went with the EFI 4150 550-516 unit. 800cfm and good to 650 hp. Has a built in pressure regulator and is what sold me on it.

Going to document my install as I go. I'm curious as to how my throttle and kickdown stud fit. I am assuming I'll have to tweak it.

View attachment 1037855

I installed the same system. Had some health issues that slowed me down but it went pretty easy. You won’t need a ton of splices but get the good quality ones. I found I had enough wire length to mount the ecu just above my dimmer switch so it stays out of the heat. One problem I ran into was the Holley distributor was not indexed the same as my old MSD unit. I set it on #1 TDC before the install and didn’t realize the new unit actually pointing at #2 cylinder on TDC. After some backfires I figured it out…

 

[threewood]

Weather cooled so I have driving the GTX. Couldn't be more happy with how it runs. Throttle response is insane. From a red light, no traffic at night, when I punch it the Nitto 555 street slicks instantly go to smoke.

 

[64fury74charger]

Wow this is a great thread for learning about tuning the Sniper system. I have installed new fuel tank with the pump and Sniper efi and just recently got the Hyper spark components at my door. Weather here has been unfavorable for working on my car, but recently drove to work for a few days and there’s lots to learn.

I do not consider myself tech savvy but I can usually climb out of a learning curve fairly well. Starting whether cold and sitting for 2 weeks or at temperature after a drive is really crisp and as stated by others you can take off dead cold if you want.

I have noticed what seems like intermittent popping from the exhaust at cruising speeds which are currently around 2600 rpm at 60. Right now I have a no name r t r distributor and MSD blaster coil that have worked fine with the Edelbrock carburetor.
I am looking forward to upgrading the ignition system and see what changes.

 

[themechanic]

Weather cooled so I have driving the GTX. Couldn't be more happy with how it runs. Throttle response is insane. From a red light, no traffic at night, when I punch it the Nitto 555 street slicks instantly go to smoke.

No doubt due to the non-progressive throttle action. There is a progressive link for the throttle on the non Stealth models only that solves the sudden take off from a stop.

 

[threewood]

Wow this is a great thread for learning about tuning the Sniper system. I have installed new fuel tank with the pump and Sniper efi and just recently got the Hyper spark components at my door. Weather here has been unfavorable for working on my car, but recently drove to work for a few days and there’s lots to learn.

I do not consider myself tech savvy but I can usually climb out of a learning curve fairly well. Starting whether cold and sitting for 2 weeks or at temperature after a drive is really crisp and as stated by others you can take off dead cold if you want.

I have noticed what seems like intermittent popping from the exhaust at cruising speeds which are currently around 2600 rpm at 60. Right now I have a no name r t r distributor and MSD blaster coil that have worked fine with the Edelbrock carburetor.
I am looking forward to upgrading the ignition system and see what changes.

Nice! See what your A/F is doing during the popping. Could be a miss?

 

[Sweet5ltr]

Wow this is a great thread for learning about tuning the Sniper system. I have installed new fuel tank with the pump and Sniper efi and just recently got the Hyper spark components at my door. Weather here has been unfavorable for working on my car, but recently drove to work for a few days and there’s lots to learn.

I do not consider myself tech savvy but I can usually climb out of a learning curve fairly well. Starting whether cold and sitting for 2 weeks or at temperature after a drive is really crisp and as stated by others you can take off dead cold if you want.

I have noticed what seems like intermittent popping from the exhaust at cruising speeds which are currently around 2600 rpm at 60. Right now I have a no name r t r distributor and MSD blaster coil that have worked fine with the Edelbrock carburetor.
I am looking forward to upgrading the ignition system and see what changes.

Depending on if it's a 'B' or 'RB', please verify the shaft length prior to installing the new Hyperspark distributor. Long story short, they were cutting them short originally on 'B' motors and I had to send MSD a few of my distributors for them to acknowledge this.

 

[64fury74charger]

Nice! See what your A/F is doing during the popping. Could be a miss?

I think it’s a miss and it’s also intermittent or random may be a better description. My plan is to install the hyper spark distributor, cd box and coil for timing control instead of trying to dial in the current system. Time for me to update my computer skills and learn how to tune the entire system. The handheld monitor was not in a good position to check while driving so I couldn’t check the A/F reading.

 

[64fury74charger]

Depending on if it's a 'B' or 'RB', please verify the shaft length prior to installing the new Hyperspark distributor. Long story short, they were cutting them short originally on 'B' motors and I had to send MSD a few of my distributors for them to acknowledge this.

I will definitely check the shaft and it’s a B 400. I am aware of some issues with the tip being short . Thank you for your help.

 

[themechanic]

Holley has a bunch of tech how to videos on their YouTube channel.

 

[Sweet5ltr]

I will definitely check the shaft and it’s a B 400. I am aware of some issues with the tip being short . Thank you for your help.

By the way, I ran into an owner with a Sniper the other day at an exhaust / welding shop that was experiencing tuning issues. He was unaware of the Holley Sniper Facebook Group. While I'm no longer on FB, that was the place to be for tuning info, similar to the FiTech group which was the only place for tech support a few years ago. So if you're not on that group already, it may be beneficial or provide some assistance once you start really getting involved in the Holley EFI software.

If you look deep in the group docs, you'll probably still see my 'spare parts' list of all the user replaceable parts for the Holley Sniper EFI system (parts store #'s & OEM vehicle / year info to source). I was fairly involved in that group early on.

 

[rmchrgr]

He was unaware of the Holley Sniper Facebook Group.

Holley has forums specifically for their EFI products.

https://forums.holley.com/forumdisplay.php?82-Sniper-EFI

 

[Sweet5ltr]

Holley has forums specifically for their EFI products.

https://forums.holley.com/forumdisplay.php?82-Sniper-EFI

Yes they do, but most people are on the FB Group.

 

[rmchrgr]

Yes they do, but most people are on the FB Group.

Not trying to start an argument in threewood's thread about where to get your info from but I'm not so sure "most people" are on the FB group over the forums, suppose we'll have to agree to disagree on that. The Holley forums are pretty good, can't see looking elsewhere for Sniper-specific tech?

I'm not on FB so I really can't comment on the validity of the info there but as a general rule I wouldn't trust anything from there anyway.

To each their own I guess.

 

[themechanic]

I don't like the way customer support is farmed out to the internet. Phone calls with an actual expert who speaks English well is the only way it should be done.

These systems are advertised as working flawlessly out of the box. But I don't know anyone, 8ncluding YouTubers, who don't have problems with EFI conversions.

 

[Billccm]

I don't like the way customer support is farmed out to the internet. Phone calls with an actual expert who speaks English well is the only way it should be done.

These systems are advertised as working flawlessly out of the box. But I don't know anyone, 8ncluding YouTubers, who don't have problems with EFI conversions.

The latest issue of Chrysler Power magazine sort of addresses what you say, although they defend that they have never experienced a out of box defect.

 

[Sweet5ltr]

Not trying to start an argument in threewood's thread about where to get your info from but I'm not so sure "most people" are on the FB group over the forums, suppose we'll have to agree to disagree on that. The Holley forums are pretty good, can't see looking elsewhere for Sniper-specific tech?

I'm not on FB so I really can't comment on the validity of the info there but as a general rule I wouldn't trust anything from there anyway.

To each their own I guess.

Holley forums are great. As I mentioned before, I created a word document that listed all the user serviceable parts with standard OEM part numbers and a Holley Representative also assisted with the vehicle year / model info (where you could purchase these locally, and not from Holley) for the Holley Sniper owners group which has 20,000 members, and most of my information was found by searching through Holley's forum threads.

I'm no longer on FB, was banned last year. I've created an account recently to essentially browse the marketplace, and it's interesting to see that not much has changed on that group, owners are still having the same problems they were two years ago with injector & ECU related failures. It's really unfortunate they haven't sorted these problems out.

So, when people ask about info on these systems or need some help (general tuning questions), I always mention the group if they are on FB. Not all the information is relevant, but with a search, nearly all the issues myself and others had have been solved at one point or another.

 

[rmchrgr]

Holley forums are great. As I mentioned before, I created a word document that listed all the user serviceable parts with standard OEM part numbers and a Holley Representative also assisted with the vehicle year / model info (where you could purchase these locally, and not from Holley) for the Holley Sniper owners group which has 20,000 members, and most of my information was found by searching through Holley's forum threads.

I'm no longer on FB, was banned last year. I've created an account recently to essentially browse the marketplace, and it's interesting to see that not much has changed on that group, owners are still having the same problems they were two years ago with injector & ECU related failures. It's really unfortunate they haven't sorted these problems out.

So, when people ask about info on these systems or need some help (general tuning questions), I always mention the group if they are on FB. Not all the information is relevant, but with a search, nearly all the issues myself and others had have been solved at one point or another.

OK, fair enough. I'd like to see that word doc if you have a direct link for it. What I really would like though is a list of the terminals they use for their wiring harness. Most of them are Metri-pack variants but there are some oddballs in there. I searched them all out and have a jumbled up document with what they are but it would be nice to have a clear, concise list of them and where they go.

My take on the ECU and injector failures is user error. Like mentioned above, I think a lot of people fall for the "plug and play" advertising and then don't bother to do any research about it. It's definitely not as easy as they make it out to be. First and foremost wiring needs to be in good condition, have to wonder how many people out there are using quick splices and such on 53 year old wiring, they're bound to fail.

Case in point, a guy in my neighborhood called me to help him the other day with a Sniper install because he had seen it on my car and wanted it. He started in on it but didn't get very far. When he called he admitted he had no clue what any of it was about and was overwhelmed. I was polite and did my best to explain how everything works but he was clearly in over his head and likely would have fallen in to that category of fails. I told him point blank he needed to re-do his wiring or it would never work right. His main alternator feed was hanging on by a little strand of wire. It was crazy to me that he bought all this stuff and had no clue how it worked or what it did.

He also said he was not terribly computer savvy so I'm guessing that's also a stumbling block for many people. How many guys out there just use the generic wizard tune and then say it sucks and never ran right? You have to build a tune and get involved with it even if your combination is stock or whatever. It's not rocket science, the software is basically a graphical representation of air/fuel/spark tuning but I suppose looking at all the software could make your head spin if you don't know what you are looking at or what it's supposed to do.

 

[451Mopar]

There is a bit of a learning curve when going from a low pressure, carbureted, mechanical fuel system to a high pressure, EFI, computer controlled system.
First, don't think of EFI as a carb replacement, you really are changing the entire fuel system. The fuel pumps, regulators, filters, pump locations, fuel lines, will be different, and usually EFI will also use a return fuel line from the regulator.
The high pressure EFI fuel pumps are not good at creating suction. An In-Tank pump is usually the best, quietest, and adds lift to the pump. Most In-tank pumps come with an inlet sock type filter. If using an external pump, it should have a low restriction 100 micron or less inlet filter. Pump outlet filters are usually 10 micron, and I think Holley says max of 30 micron? The pump outlet side is high pressure, usually 3 or 4 Bar (43.5 psi or 58 psi) on normally asperated engines, and higher on boosted engines. The fuel lines, connectors, clamps, and fittings need to work with the higher pressure (and with todays alcohol enhanced fuels.) Most (if not all) aftermarket EFI conversions are setup to use -AN fittings too.
Using your old corroded fuel lines with EFI can be a problem if it is past the fine filter. Any crud that gets past the fine filter can clog up an injector.
Carbs can run OK with some sediment that gets into the fuel bowl.
If your used of seeing a constant fuel pressure going to your carb, the EFI fuel pressure will vary depending on manifold vacuum/pressure.

Anyhow, I think the fuel system is where many people new to EFI make mistakes to where they complain they have a "bad injector" when it is likely has trash in it from the old fuel system. I think the electrical wiring most people handle fairly well, but get lost with the EFI terminology used for programming/tuning the ECU software.