Sniper Efi 68 Charger

[Wietse]

My cam is 238/244 @ .050" (283/291 advertised) so just a little larger but .572/.576" lift and more area under the curve.
I had set my cranking timing at 16* and idle at 20*, it starts easy but it does not stay running by itself as well.
I need to give just a little throttle (3-4%) to maintain a 1000-1200 rpm idle for a few minutes otherwise it will stall.
If i slowely release the throttle the IAC will open up to 100% but cannot maintain the idle speed of 875 rpm and will slow down untill stall.
Once warmed up it idles fine, i only have 75-80 kpa manifold pressure which is problematic to say the least.
I think yours will need some learning time and to get the fuel learning table filled in, it will add/reduce fueling as a matter of learning.
Like i mentioned before, you can change the idle AFR to a little richer and see how that works, with your vacuum surely it will run better than mine.

And btw, that is a nice '68 Charger.
My Coronet R/T had originally that same color, but some PO had painted it Sublime green.

 

[Pool Fixer]

My cam is 238/244 @ .050" (283/291 advertised) so just a little larger but .572/.576" lift and more area under the curve.
I had set my cranking timing at 16* and idle at 20*, it starts easy but it does not stay running by itself as well.
I need to give just a little throttle (3-4%) to maintain a 1000-1200 rpm idle for a few minutes otherwise it will stall.
If i slowely release the throttle the IAC will open up to 100% but cannot maintain the idle speed of 875 rpm and will slow down untill stall.
Once warmed up it idles fine, i only have 75-80 kpa manifold pressure which is problematic to say the least.
I think yours will need some learning time and to get the fuel learning table filled in, it will add/reduce fueling as a matter of learning.
Like i mentioned before, you can change the idle AFR to a little richer and see how that works, with your vacuum surely it will run better than mine.

And btw, that is a nice '68 Charger.
My Coronet R/T had originally that same color, but some PO had painted it Sublime green.

Thanks for the info! I need to put a vacuum gauge on it too. Also I have an actual fuel pressure gauge I want to Plumb in.

When i start it, and first lights off, it’s barely running. One little shot of accelerator pedal and it settles immediately into a solid idle and I never have to touch pedal again even before it warms up. I’m also getting some of the dreaded whistling so I ordered a penoloc 1/2” spacer. It’s just they initial start that’s an issue for me

Thanks for the compliment. It will be nicer when I wash it. Also, I have a dr diff 13” brake kit going on. That’s next.

 

[Wietse]

I considered a fuel gauge but realized it is another leak potential, i checked it on the test port and is at 60 psi which is all i need to know.
To get mine started i just cycle the ignition 2x and allow a initial pump shot 2x and it starts straight away.
There is another fuel setting (post start fueling) that allows you to increase or decrease the fueling once it started.
Note this is not the initial pump shot prior to start, it is regarding the fueling once it is actually started.
Since yours starts ok, but stalls directly after i think that is where you can look at next, see what the numbers are and increase it with say 10% (i.e. it states 50lbs/hr of fueling, you increase it to 55lbs/hr)
I think that once you reconnect the pcv again, which will allow more air to enter, it might need even more fuel post start.
Not sure if you already played with the EFI software with a laptop?
I just started fingering it with this, very interesting but lots to learn there.
Though there are many options that can be easily changed on the fly and see what the changes are.
Just be aware that the sniper file you change is the one on the ECU and not on the SD card.
If you want to save a copy of your tune you can save it on the SD card.

 

[Pool Fixer]

I considered a fuel gauge but realized it is another leak potential, i checked it on the test port and is at 60 psi which is all i need to know.
To get mine started i just cycle the ignition 2x and allow a initial pump shot 2x and it starts straight away.
There is another fuel setting (post start fueling) that allows you to increase or decrease the fueling once it started.
Note this is not the initial pump shot prior to start, it is regarding the fueling once it is actually started.
Since yours starts ok, but stalls directly after i think that is where you can look at next, see what the numbers are and increase it with say 10% (i.e. it states 50lbs/hr of fueling, you increase it to 55lbs/hr)
I think that once you reconnect the pcv again, which will allow more air to enter, it might need even more fuel post start.
Not sure if you already played with the EFI software with a laptop?
I just started fingering it with this, very interesting but lots to learn there.
Though there are many options that can be easily changed on the fly and see what the changes are.
Just be aware that the sniper file you change is the one on the ECU and not on the SD card.
If you want to save a copy of your tune you can save it on the SD card.I

I think you may be onto something. I did see that setting but was afraid to touch it lol. I also went into the iac settings and saw the AC kick was set to 50%. read some online from other users that the system behaves poorly unless tha'ts zero. I did reset it which may help with my IAC issue but not with starting issue. it's inside my shop on my lift and I have to move a few pallets of crap to get it out so I'm done F'ing with it today have stuff going on this weekend but I can look at it for a bit on monday.

I'm gonna get a vacuum gauge, prob try to test for vacuum leaks with propae gas (not lit!) I'd hate to go to all this trouble to find out I had some kind of small vacuum leak. Exhaust leaks first. try to baseline this thing.

I have not tried the laptop yet. I don't know if I ever will. I'm good at what I do for a living and EFI aint it. I won't rule out getting it dyno tuned. have to look into that.

 

[Wietse]

Yeah, you better ensure there are no vacuum leaks and get the basics right before anything else.
I really recommend using a laptop with the EFI software, it is so much easier to set graphs etc. for fueling and high idle.
It also allows you to smooth out the timing table which gives much more better transitions, the basic maps are not ideal.
There are even Excel files out there which allow you to enter the wanted timings at idle, WOT and cruise and it will fill in the 31x31 map smoothly.
Thats what i am currently playing with, but the weather is no good with snow and all the salt on the roads.
Mine is staying inside for the time being.

 

[70ChargerRT]

Yeah, you better ensure there are no vacuum leaks and get the basics right before anything else.
I really recommend using a laptop with the EFI software, it is so much easier to set graphs etc. for fueling and high idle.
It also allows you to smooth out the timing table which gives much more better transitions, the basic maps are not ideal.
There are even Excel files out there which allow you to enter the wanted timings at idle, WOT and cruise and it will fill in the 31x31 map smoothly.
Thats what i am currently playing with, but the weather is no good with snow and all the salt on the roads.
Mine is staying inside for the time being.

I’m about to complete my install with my Sniper X-Flo. I’m dreading the tuning part. You’re running just a tad bigger cam than I am with about the same lift with my 1.6 rockers. It’s a HR 236/242 @ 110 with 544 lift.I only had 7-8” vacuum before but FASTMAN swears he can help me get it tuned to run great. I only went with the x-flo cause I may build a 700hp motor next time. Only thing that worries me is RFi and tuning problems. Definitely going to tune mine with a laptop as you mentioned. That’s FASTMAN said it took to get these bigger cam engines dialed in.

 

[Wietse]

Mine is doing 7-8" vacuum as well, good to read from someone else with a Hughes Engines cam that they have the same.
Many people are convinced i have a serious vacuum leak that is causing the low vacuum but i know i don't have any vacuum leaks.
One thing i likely have to accept is that it will never start easy by itself and keep idling when it is cold, once it is at operating temperature it idles ok and drives like a rocket. (well, the starting part is ok, but the independent running when cold is the issue)

One thing i learned so far is to get the running parameter as steady as possible for a decent idle, the Idle Spark for example is not doing any good on mine and it is better to have a fixed timing number. (mine is at 20*)
Same counts for the target AFR, just a steady rich mixture works best.

I don't know who FASTMAN is, but i am reading up on the Holley EFI forums, there are a few guys there that know a lot about the Holley EFI stuff and how and what to correct.

 

[Pool Fixer]

Mine is doing 7-8" vacuum as well, good to read from someone else with a Hughes Engines cam that they have the same.
Many people are convinced i have a serious vacuum leak that is causing the low vacuum but i know i don't have any vacuum leaks.
One thing i likely have to accept is that it will never start easy by itself and keep idling when it is cold, once it is at operating temperature it idles ok and drives like a rocket. (well, the starting part is ok, but the independent running when cold is the issue)

One thing i learned so far is to get the running parameter as steady as possible for a decent idle, the Idle Spark for example is not doing any good on mine and it is better to have a fixed timing number. (mine is at 20*)
Same counts for the target AFR, just a steady rich mixture works best.

I don't know who FASTMAN is, but i am reading up on the Holley EFI forums, there are a few guys there that know a lot about the Holley EFI stuff and how and what to correct.

I bought my system from fast man. For a fee, they will connect to your system and tune it remotely. It’s not cheap but once I’ve verified that I don’t have some other problem, I may go that route.

I planned so much and tried so hard to avoid any of this but here I am. Double edge sword. I changed a lot of parts so I’d be starting fresh but when you change that much, it leaves any of those things as a possibility.

Its not all doom and gloom. It idles ok, drives even better and I know it will be spectacular once it’s done.

 

[Wietse]

The biggest misunderstanding of thing like this is that it most of the time it will not work as advertised from the start.
There is still some work to be done on it, i believe the engineers at Holley did a good job on making it tunable by the end user with their software.
It is a route of trial and error and you learn as you go.
If you are using the SD card (with or without laptop) to save a working config, you are then able to make changes and try different things.
If you screw things up you delete the config and load the saved config back to the ECU and you can start over again with the lessons learned.

For them (Fastman) to do any tuning they will require you to do some data logging for them to see what the system does and make changes based on the findings in the logging.

 

[Pool Fixer]

Feel like I'm moving the needle in the right direction. \

-Changed exhaust flange gaskets to Remflex which are 2x the thickness of the ones I had in there. No more leaky. Part of my issue was I got the bright idea to use stainless bolts I had for that. They were in for a week and not much run time and 2 of 4 broke taking them out. I moved on to grade 8 and a fella was really able to feed her the onions. She tight now.

-Changed plugs. I had gapped The Rj12YC I put in recently to .053 tho. I decided this was not a good move and I had a new set of NGK's sitting on the shelf. Gapped those to .045 thou. also made sure my new plug wires were in the right order and the boots were all the way on. Amazing how crappy plug access in on a B body big block with manifolds and PS.

With no other changes, My IAC % on a warm engine is stable at 8%. I feel like it's running smoother.
I I'd see the AFR on the display fatten up quite a lot on tip in. I got rid of most of that by cutting down on the accel enrichment. I'm at the point where the car idles and drives very well. I'm not supertuned by any means but I plan to roll with this for a few hundred miles then maybe hit up FASTMAN for a $400.00 zoom tune.

My only real issue is start up. I still have to gas it. I've asked over at the holley forum and Andy F responded it sounds to him like when I'm gassing it a little on start up, I'm realling adding more air- not enough air at crank vs not enough fuel. I'm still playing with that.

Onto my Dr. diff cobra brakes. thats the next project. then onto altering the mounts to my retrofitted seats cause they are too high. and then onto rebuilding a spare gauge cluster I have maybe with a tic toc tac... always a lot on the list!

 

[rmchrgr]

Feel like I'm moving the needle in the right direction.

-Changed exhaust flange gaskets to Remflex which are 2x the thickness of the ones I had in there. No more leaky.

My only real issue is start up.

Exhaust leaks were killing my Sniper tune to the point of my throttle body being black. Seems like you've got that under control but it's worth repeating that you gotta stay on top of stuff like that with EFI or things go south in a hurry.

Startup is tricky. There have been times where I had my car consistently starting on the first try but then I'd change stuff and it would go back to 2-3 attempts before it would fire. Much like a carb, warmer ambient weather definitely seems to help. That shouldn't matter with EFI but unfortunately it does seem like temps do come into play on some level. It can be definitely be tuned to start consistently in all conditions, just takes a lot of trial and error. Take some data logs and upload them to the Holley forum and see if you get any input.

Before messing with the enrichment settings too much though, try the fuel prime multipliers first. You can also easily try more or less startup timing.

There's also this link:
Tuning Sniper startup

Here's my thread I've had going on and off for three years now. Has a bunch of EFI stuff in it. Probably more useful for learning what not to do.

'68 Coronet EFI

 

[70ChargerRT]

Did some tuning Saturday with Fastman. Ran in to an intermediate problem that kept shutting my car off in between tunes. I would lose all communication with the ECU and the fuel pump wouldn’t shut off when this happened. So the problem may be my fault which includes interference and a charging problem. Holley wants me to have the Sniper Only on the side post and that’s it, I had other hot leads with it that may have been causing interference. I was supposed to run a different regulator with my 130 amp alt and ground the alternator itself which I didn’t, so the charging issue is solved. Holley wants me to also put a relay on my ignition source also to prevent any noise that could come from it also. We almost finished the tune. Car starts awesome and idles great when running lol so hopefully I can get it going this weekend without any problems.

 

[rmchrgr]

RFI is a PITA. Seems like anything can cause it including the air cleaner stud but having ‘other stuff‘ tied in to the same battery post is a definite no-no. At least you didn’t try to run it to the coil positive stud or some such thing.

Holley really beats you over the head with the “clean power” idea and you understand why now. My Sniper main power and ground go to the top posts and other things go to the side posts. I still get RFI here and there, you can see it in the data traces but it’s not significant enough to shut the ECU off.

Seems like wiring (and subsequently RFI) is what trips people up the most with these things. Good you got it figured out.

 

[70ChargerRT]

RFI is a PITA. Seems like anything can cause it including the air cleaner stud but having ‘other stuff‘ tied in to the same battery post is a definite no-no. At least you didn’t try to run it to the coil positive stud or some such thing.

Holley really beats you over the head with the “clean power” idea and you understand why now. My Sniper main power and ground go to the top posts and other things go to the side posts. I still get RFI here and there, you can see it in the data traces but it’s not significant enough to shut the ECU off.

Seems like wiring (and subsequently RFI) is what trips people up the most with these things. Good you got it figured out.

He didn’t mention it but I’ve heard of people running a ground from the sniper also probably because I told him I have grounds everywhere. Grounds from the drivers side head to battery, passenger side head to firewall, engine block to frame, frame to battery post, rad support to battery.

 

[Loulang]

I installed the sniper efi on my 66 charger with a 383 and the gas tank this winter. I have had the chance to fire it up and let it get warm but soon as the idle comes down she stalls out sometimes. I’m definitely not computer literate so I’m sure I will be looking for help in the near future The roads still have some salt here in northern Michigan so I haven’t had the chance to drive her yet I’m hoping to find someone close that can tune her for me.

 

[70ChargerRT]

I installed the sniper efi on my 66 charger with a 383 and the gas tank this winter. I have had the chance to fire it up and let it get warm but soon as the idle comes down she stalls out sometimes. I’m definitely not computer literate so I’m sure I will be looking for help in the near future The roads still have some salt here in northern Michigan so I haven’t had the chance to drive her yet I’m hoping to find someone close that can tune her for me.

There’s guy

I installed the sniper efi on my 66 charger with a 383 and the gas tank this winter. I have had the chance to fire it up and let it get warm but soon as the idle comes down she stalls out sometimes. I’m definitely not computer literate so I’m sure I will be looking for help in the near future The roads still have some salt here in northern Michigan so I haven’t had the chance to drive her yet I’m hoping to find someone close that can tune her for me.

You can do remote tuning. They are several guys that can do it. I downloaded TeamViewer and it basically lets the tuner take control of your laptop and he can do the tune like that but you really some fast Wi-Fi or 5G if using a hotspot. They will require you to be able to read a timing light to double check the timing on it. Just make sure to go over your wiring and don’t make the mistakes I did.

 

[Loulang]

There’s guy

You can do remote tuning. They are several guys that can do it. I downloaded TeamViewer and it basically lets the tuner take control of your laptop and he can do the tune like that but you really some fast Wi-Fi or 5G if using a hotspot. They will require you to be able to read a timing light to double check the timing on it. Just make sure to go over your wiring and don’t make the mistakes I did.

I do not have good Internet service where I live lol I live in the woods my town is about 10 miles away and if ya blink you will miss it i’m sure I will get it figured out I know I can always count on Well known members here.