Another EFI Sniper question...

[GMSilk_Fj60]

I been driving my EFI sniper on a FJ60 (3" lift on 33x10.5r15s, fj62 exhaust manifold) for about 3 months now. Mostly daily driving back roads and at the farm but I also did a 800 mile round trip up the east coast all highway. I've put about 2,000 miles on the sniper at this point and it appears to have learned about all it can. Love almost everything about it, except the bog down at full throttle.

Did anyone have to mess with the fuel enrichment settings to get better throttle response between 50%-100% throttle? If it pulls well up to roughly half throttle and then bogs out, could it perhaps be a timing advance issue?

She pulls well driving gently but not having the ability to let er` loose from time to time is a bit lame. (yes, I know its a tractor motor, no i dont want a v8, etc etc.). My JimC carb had better full throttle response so I know I can tune this thing better. Just looking for a few places to tweak/improve.

 

[SteveH]

My AFI TBI is like this - you have to 'sneak up' on full throttle, or else it bogs a bit. I will be interested in any responses. I wonder if it is a physical limitation of the throttle body that is not easily 'programmed around'.

 

[Seth S]

Can you plug a laptop in and see the fuel curves? I know the sniper has the little digital display but I think you need to get in and play with the maps to solve your issue.

 

[Dustin Messina]

Have you seen the fj40 drag race here? I know @FJ60Cam built a beast of a 4.4 motor, however, he had no power band loss at all. I too have a Sniper and don't have any of the issues you stating. When I get in the pedal it moves, however, I do think you are able to customize your fuel maps but I've never needed too!

Builds - Mississippi Delta Beast - 1974 FJ-40 Rescue and Rehabilitation

Fast forward all this BS tech. Does the 4.4 liter 2F live up to all the hype? Well I drove up highway 51 in Patina until I passed an uglier vehicle. We switched seats and I got a nice drive in the Delta Beast. It felt damn strong. Patina is no slouch. New motor. @FJ40Jim carb. Dui...

forum.ih8mud.com

 

[WSOPgold2012]

Hvnt had enuff drive time to really notice this ..but, don't believe I have any "bog down" either. I'm not heavy footed tho...and hardly ever get to fill throttle, perhaps why I've never noticed.

 

[GMSilk_Fj60]

@Dustin Messina, I got my sniper from @FJ60Cam so i'm very familiar with his work. I studied just about every sniper thread on here (including yours extensively, nice rig) and elsewhere and only found some examples on the Holley blog (title: 383 Bog down at WOT). I'll go over vacuum and timing first, then plug to computer in and look at the live data.

Is there a thread where people have uploaded their sniper files? I'd be interested to compare the variability between how each has learned...

 

[Seth S]

Is your sniper setup controlling ignition too?

 

[Zjohnsonua]

PM sent

 

[GMSilk_Fj60]

My 60 was desmogged and running well prior to the sniper.

@Seth S I'm running a JimC recurved dizzy at about 11 degrees currently. Outer port is the altitude advance port, so it is plugged. The master vac advance is routed to the front of the sniper direct line without any T-links or VCV's. Id like to avoid the HEI big cap and electronic ignition. Im a fan of Toyota's Dizzy and want to make it work.

I'm running the stock air cleaner assembly but I removed the HIC vacuum lines. With There is normally a split line during a desmog that i omitted that might do something i've missed. I am looking over my charcoal canister routing and PCV routing as potential vac leak sources... but I doubt thats the issue.

For fuel passage, I used the hardlines on the frame (send and return) to a in-tank fuel pump. I have an inline fuel pressure gauge that holds strong at the targeted 60psi so i doubt fuel flow is the issue.

 

[RLMS]

My 60 was desmogged and running well prior to the sniper.

@Seth S I'm running a JimC recurved dizzy at about 11 degrees currently. Outer port is the altitude advance port, so it is plugged. The master vac advance is routed to the front of the sniper direct line without any T-links or VCV's. Id like to avoid the HEI big cap and electronic ignition. Im a fan of Toyota's Dizzy and want to make it work.

I'm running the stock air cleaner assembly but I removed the HIC vacuum lines. With There is normally a split line during a desmog that i omitted that might do something i've missed. I am looking over my charcoal canister routing and PCV routing as potential vac leak sources... but I doubt thats the issue.

For fuel passage, I used the hardlines on the frame (send and return) to a in-tank fuel pump. I have an inline fuel pressure gauge that holds strong at the targeted 60psi so i doubt fuel flow is the issue.

I would go to your settings, Change the fuel prime to 120-150%, then change your Target AFR WOT to 13.5-14.1 and idle AFR to about the 12.5-low 13's . Double check timing. 8.5-11* Find the happy spot! This is what we dial them into usually. We see 8 hp increases or decreases with minimal changes at 6300 feet on stock cam and stock compression 2F's on a wheel dyno!

Make sure your running good plugs and wires. Also throw in a high voltage coil! Throttle response becomes much better!



From "The inter-web's"
The AFR table is a 3×3 matrix – the AFR is interpolated between these breakpoint values. This means that if you’re breakpoints are 45kPa at 14:1 and 95kPa at 12:1, operating at 70kPa will result in 13:1 target.

Idle AFR Target = Target AFR of fuel control when the engine is at Idle. Most engines will tolerate as rich as 12.7:1, and some will “like” 14:1.
1100 45kPa = AFR at 1100 RPM and 45kPa – this is typically just “off-idle” with very low throttle opening. Different cams will require different AFRs at this point. A stock cam will work fine at 14.5:1. A lumpy cam might like 13.3:1 or 14.5:1.
3000 45kPa Cruise = AFR at 3000 RPM and 45kPa – typical of a light cruise, but not, for example, overdrive cruising at lower RPMs and higher loads. Suggested range 13.4 – 14.7:1.

Justin

 

[Dustin Messina]

My 60 was desmogged and running well prior to the sniper.

@Seth S I'm running a JimC recurved dizzy at about 11 degrees currently. Outer port is the altitude advance port, so it is plugged. The master vac advance is routed to the front of the sniper direct line without any T-links or VCV's. Id like to avoid the HEI big cap and electronic ignition. Im a fan of Toyota's Dizzy and want to make it work.

I'm running the stock air cleaner assembly but I removed the HIC vacuum lines. With There is normally a split line during a desmog that i omitted that might do something i've missed. I am looking over my charcoal canister routing and PCV routing as potential vac leak sources... but I doubt thats the issue.

For fuel passage, I used the hardlines on the frame (send and return) to a in-tank fuel pump. I have an inline fuel pressure gauge that holds strong at the targeted 60psi so i doubt fuel flow is the issue.

I ran mine with a Jimc recurved Dizzy for the first few thousand miles and it ran great. I ran it with one vac line for the longest time, then installed a VSV towards the end because I realized i didn't have my distributor breathing at all. I too ran around 11-12 degrees and it was money. Curious what throttle linkage did you go with? Also When you say 50-100% throttle are you talking about actually pushing pedal down towards the floor or are you referring to TPS readings?

 

[GMSilk_Fj60]

Thanks all. Now I cant wait to get off work and look at this...

I use a lokar cable with a spacer to get the pedal down closer to stock.

TPS sensor reads just shy of 50% before it bogs down. It doesn't bog free reving, only under load.

If anybody is interested in the truck, my buddy made a video of the rig. I dont claim to be an expert and over use the term "bomb proof" but I describe some of the truck throughout the vid including the Sniper.

 

[Borrego]

Nice 60! Great video. If you make your trip out to Portland, stop over in Coeur D Alene, would love to check out the mods in person! and swap cruiser stories.

Cheers!

 

[WSOPgold2012]

Enjoyed the video...thanks for sharing!!

 

[wngrog]

 

[iCruiser]

Anyone have pics of their Lokar cable setup with the Sniper to include the throttle bracket mounted and where cable enters firewall?

 

[wngrog]

Anyone have pics of their Lokar cable setup with the Sniper to include the throttle bracket mounted and where cable enters firewall?

Just did that today. Step by step in the Texas Reds thread

 

[iCruiser]

Thanks. Cam actually just called and walked me through the steps on the phone. Pics here are a huge help! Sure I will be back for more questions.

 

[wngrog]

If anyone is looking for a step-by-step to install a Sniper here is my last install.

Took me about 23 hours start to finish with a few small other items that were engine related.

Builds - Texas Reds - The Tale of Two Red 40’s

I stalled out when I realized I did not have any normal height greaseable shackles. The ones one the truck are 5” eye to eye. Stock are 3”. The OME greaseable are 3” so that keeps your caster good. This truck, not only has 3” taller springs in the front, it also has the aluminum caster shims...

forum.ih8mud.com

 

[GMSilk_Fj60]

Id advise against the Lokar cable. I am working on a way to go back to a mechanical linkage. The Lokar feels... bad.