When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I am going to install a sniper EFI system this winter and I was looking to get some advice on the fuel system..
My car was a factory L69 84 TA it is running a mechanical pump from the previous owner on a carbed 350. It looks like I have 3 options
1. Run the external pump with the holley kit
2. Sump under the hood
3. intake pump
I have figured out the first two options does anyone have any advice on the 3rd? Is there a setup that is easy to install in our tanks?
Any advice from anyone who has done it?
For sure go with the in tank pump, I run a walbro 255 lph , make sure you change the return line size to 3/8 it needs to be same or larger than feed line. The external pumps are nothing but problems with the Sniper.
These Sniper's are getting more and more popular. I have an intank setup out of an '92 Z28 that I flared for fittings. I would run that with a universal AEM pump, then would just worry about the feed and return lines being accurate in size on your '84, and just correct for if they are smaller...
Yes exactly, I have a 91 which uses that same one , then there is some cutting and reconfiguring of the tubes, but fairly easy to do you will also need a 10 micron inline filter ,
I run the sniper TBI efi and fortunately my car was an in-tank pump from the beginning. however I run a racetronix hotwire kit, with racetronix relay, and the racetronix in-tank wiring upgrade too. I did NOT use the holey sniper efi fuel system relay. I run a racetronix 340lph pump and a 10 micron filter on a -8 ptfe feed line and a -6 return line. never had a fuel system issue aside form I was not venting the tank pressure properly by crimping closed the vent port tube that used to go to the charcoal canister. I ended up putting a small breather filter on it (while also keeping the factory oem acorn rollover vent valve) and I have not had any issues since then. I would opt for an IN-TANK pump . As has been mentioned, sniper systems are sensitive and in tank pumps with proper psi are required. I am a big fan of the sniper and its basic features/tunability along with the datalogging.
Do you guys see any issues with using my stock 84 tank besides needing the TPI pickup and lines? Are there differences in the fuel sender or tank I need to be aware of?
If I remember correctly, i used the brown sniper wire for the tach on the dashboard. for my aftermarket shift light I think I tapped into it. I actually can not remember
Small update I got the fuel system done and plumed. It holds pressure between 58-60 psi and no leaks. When I get it all installed I will make a build thread with observations on how I did it.
The plan is this Saturday get the wiring done. For now I am going to leave the distributor regular mechanical advance. Later after I know the rest is good I will try to control my ignition.
I need to 1. Install the sensors (O2 and temp) and wire them up
2. Run wires for the fuel pump using the factory bulkhead and plugs
3. Wire distributor and ignition Coil
4. wire power and grounds.
Mechanical items are bolted in place and the throttle cable is in place but I will probably play with the adjustment later.
that is exactly what I did with my setup... I left the timing control to the mechanical advance of the MSD 85551 distributor for a few weeks. Once I established that the engine and everything connected to it was working good, I converted timing control over to the sniper but still using the msd distributor (locked out). A few months later, I went for full blown timing control and got the holley hyperspark ignition system and everything works together seamlessly.
Its alive. The walboro 255 is working great. No leaks on any of the fittings and it started and ran perfectly. It idles about 850 rpm now which is my set point and the fans turn on at a perfect 210F and off at 195. The wiring is ugly right now so next couple weekends will be about cleaning it all up and then putting the interior back together. I could not be happier. When I get it all done I will make a post with PNs and some how to information.
cool. there is a bunch of stuff you can do with the sniper handheld, but LOTS more you can do with a laptop. so, keep in mind that if you get the Y-splitter and CAN-BUS cable you can tune in real time.
cool. there is a bunch of stuff you can do with the sniper handheld, but LOTS more you can do with a laptop. so, keep in mind that if you get the Y-splitter and CAN-BUS cable you can tune in real time.
Awesome I did not know. I will have to get one in the spring. It is about 10F outsife now and snowy so I have plenty of time to get the car back to normal before I start driving.
exactly! I was in the same situation as you are just last February. I took it one step at a time . Enjoy. Datalogging and examining the datalogs is super fun too.
I know it is controversial but I cut a fuel pump access hole. Then I used m6 nutserts and bolted on a new cover. I'm going to use some gas proof sealer similar to what Honda does for their cover between the two panels when I button it all up.
We finally had some decent weather for one week and I got to drive the car. First impressions are this system is great with a couple small issues
First drive impressions
1. Self learning was fast for the first 20 minutes I would get some stumbles when doing some light throttle and then heavy throttle. They smoothed out quickly and after 45 minutes the car felt great
2. Throttle is touchy way too touchy with stock linkage it was everything I could do to not burn out in 1st gear (5 speed) autos may be better
3. Pick up after self tuning is awesome and instant with very little throttle
Post 1st Drive
1. Progressive linkage ($14) is a must for me I installed it so first 2 throttle plates open then at 40% other two open. Starts are much easier and car is much more drivable I did have to bend the linkage a little to make it a perfect 40%
2. With progressive linkage pedal felt way to light added a weak throttle return spring to make it feel normal.
3. Hot and cold starting the car is causing the system to go super rich and stall the car. I believe this is because the new tune values in the table.
4. 15% fuel removed across all coolant temp values for after start enrichment. Hot and cold starts are much better but getting a lean spike.
5. 6% fuel added back in to all CTS values for after start enrichment. Will test today but hot start yesterday was perfect.
Other impressions
1. Hand held tuning is easy to use and intuitive (can't wait to try laptop)
2. System is going a good job maintaining A/F ratios on idle, cruise and acceleration
3. Car has never been so smooth or drivable even after tuning the carb with a A/F gauge and vacuum gauge.
4. Idle is smoother than ever across all temp ranges
5. Fan control is working perfect with my settings 210 on 195 off
6. Car is making more power for sure at least in the mid range
7. I can drive immediately after starting the car cold with no coughs or stumbles edelbrock never did that
Overall it is worth the time and effort. A little more tuning will fix the hard start issue and the way it drives makes the car feel 20 years newer.
glad you like it. there is a lot to learn and get used to, but as you said, it is a great system. keep us posted. Its been a few months since I have needed to re-visit the car's tuning but now that spring is upon us, i will be getting back to it soon. im glad you are enjoying it though. keep us updated, you seem to be getting into it all pretty well. !
Saturday I put a larger charging cable from the alternator back to the battery to compliment the new alternator (63A to 94A) and I also used a relay to isolate the +12V ignition to the EFI system now the 12V_IGN line just triggers the coil on the relay and then clean battery power feeds the Sniper unit. I was not having issues this was for peace of mind knowing my +12V_IGN also fed the ignition coil I wanted to isolate it. I still have a little wiring to clean up but so far so good.
Unfortunately my radiator started to leak so a new one is on order. Cooling system should be good ,new Dual fans, HD water pump, hoses, overflow bottle and radiator. Before the leak cruising temp per the ECU was 178 - 183
A couple suggestions for removing EMI / RF from sniper.
1. Use spiral spark plug wires
2. use resistor plugs
3. New cap and rotor
4. Run signal wires separate from power and ignition
5. Isolate 12V_IGN
Just a new piece of 84 FYI my car was a L69 TA and it came with this cute little helper pump for the carb never seen one before
I have an 85 L69 and knew there was a small pusher pump but have never seen one! Were you able to hook your new pump to the OEM fitting? I plan to replace the small helper pump with a DW200 to feed a future TPI setup.
I have an 85 L69 and knew there was a small pusher pump but have never seen one! Were you able to hook your new pump to the OEM fitting? I plan to replace the small helper pump with a DW200 to feed a future TPI setup.
I did not know for sure I had a small pump in my tank so I bought a new TPI pickup ahead of time on RockAuto for $55. The Walboro 255 lph pump I used was much taller than the small helper pump and I think the factory TPI pump is also taller. You could probably make it work as long as you had the plug to go into the pump and cut the metal tube a little bit to accommodate the taller pump.
that is exactly what I did with my setup... I left the timing control to the mechanical advance of the MSD 85551 distributor for a few weeks. Once I established that the engine and everything connected to it was working good, I converted timing control over to the sniper but still using the msd distributor (locked out). A few months later, I went for full blown timing control and got the holley hyperspark ignition system and everything works together seamlessly.
Does the sniper us a knock sensor to dial back timing if there is too much advance?
Does the sniper us a knock sensor to dial back timing if there is too much advance?
No, and generally speaking most people don't run knock sensors on modified cars. Too many ways to get false knock (difference piston clearance, bore/stroke differences, gear drives, superchargers, etc).
Heck, GM had to desensitize the LT4 knock module back in the day to prevent it from retarding timing too much under load.
Installed some 1.6 ratio rockers this week after a couple drives the sniper system seems to be getting happy again. It is fun watching the learn table and seeing what compensation the system is making vs the previous setup. Unfortunately snow is back today so no more driving for a bit. I still need to make a thread for install
Hey man, did you use the holley 10 pin extra connecter for your AC relay? I did and now the compressor wont turn on, anyone have any tips??
I dont have AC but I did use it for Fans. There were options on the screen. I would try setting it up in the laptop software there were a lot of boxes to fiddle with there.
I run the sniper TBI efi and fortunately my car was an in-tank pump from the beginning. however I run a racetronix hotwire kit, with racetronix relay, and the racetronix in-tank wiring upgrade too. I did NOT use the holey sniper efi fuel system relay. I run a racetronix 340lph pump and a 10 micron filter on a -8 ptfe feed line and a -6 return line. never had a fuel system issue aside form I was not venting the tank pressure properly by crimping closed the vent port tube that used to go to the charcoal canister. I ended up putting a small breather filter on it (while also keeping the factory oem acorn rollover vent valve) and I have not had any issues since then. I would opt for an IN-TANK pump . As has been mentioned, sniper systems are sensitive and in tank pumps with proper psi are required. I am a big fan of the sniper and its basic features/tunability along with the datalogging.
@IROCZman15
Do you happen to know the part numbers that you used from Racetronix ?How did you modify the pump hanger for -8 and -6 as well ? What breather did you use on the evap line? I am having the tank pressure issue and can not figure out why. Washed out hte oil twice just parked in the garage. Thanks in advance.
Starting to put together my stealth terminator set up, once they are back in stock.
@IROCZman15
Do you happen to know the part numbers that you used from Racetronix ?How did you modify the pump hanger for -8 and -6 as well ? What breather did you use on the evap line? I am having the tank pressure issue and can not figure out why. Washed out hte oil twice just parked in the garage. Thanks in advance.
Starting to put together my stealth terminator set up, once they are back in stock.
I can dig up the parts list out of the file caboinet, but cant get to it today. remind me, and I can get it for you.
Here is a link to the online photo album where I stored the photos I took of the fuel system upgrade.
@IROCZman15
Yeah if you wouldn't mind digging those numbers or list up I'd appreciate it !
I tried to get numbers from the pic but they are just not quite legible.
Did you do -8 feed and -6 return ?
Where n NJ r u ? I'm in delco PA
Thanks in advance !!
@IROCZman15
Yeah if you wouldn't mind digging those numbers or list up I'd appreciate it !
I tried to get numbers from the pic but they are just not quite legible.
Did you do -8 feed and -6 return ?
Where n NJ r u ? I'm in delco PA
Thanks in advance !!
-6 is fine on both send and return line. -8 is a bit pointless because unless you are replacing the sender it won't flow any additional fuel since your still using the 3/8 line that's built into the hanger. I have an aeromotive pump and billet hat that will support 850 hp according to aeromotive and it uses -6 fittings.
WildCard60: I remember thinking that same exact thing both before starting my fuel system research, and while putting it all together. I remember asking either here on TGo or another tech forum about it, and I think somehow the consensus was that, that short amount of 3/8" line in the hat was not enough length to be an issue. I don't remember the details, but someone made some valid points about it. However, if it is scientifically provable that it would be a restriction if that 10" section of factory 3/8" line is hindering a the realistic use of the rest of the -8 feed line all the way up the underside of the car...well I would like to know for sure.
DaVinci: Sure, I will have to dig them up. send me a PM about it and that way I will be sure to see it and I will reply to you or to here with the stuff I ordered (fyi, i went overkill and got multiple extra fittings, hose, tools, and whatnot because I knew that my first several attempts at building PTFE -an hoses was going to take some practice. I can try to get that paperwork for you tomrrow.
I found the invoice. Sorry it took a few days. I over-ordered what I needed to buy on purpose. All of the system I put on is still on the car to this very day, and has held up exceptionally well. In fact I just checked the fuel filter (inside the billet case) last weekend, and it came apart easy, was clean, and reinstalled perfectly.
Doing an experiment on the sniper linkage system. I ditched the progressive linkage where 2 throttle bodies opened until 40% and then the other 2 snapped open. I modded a Holley throttle extension arm for the cable and switched the linkage to all 4 throttle bodies opening at the same time. The extension gives me more control from leverage and all 4 gives opening at the same time give me a smoother power band. Its weird to drive the big throttle kick at the transition is gone it just revs smooth, the low speed throttle response is also great. I made the swap because I was getting an issue with low throttle some times the car felt starved for air. Had to kink the extension a bit to clear the air cleaner
The new Sniper II has some additional outputs...I'm hoping one might be used to control TCC lockup, but I've got to do a little more digging on that. I want to be able to control / set the parameters that trigger it.
I'm strongly considering the Sniper setup for my upcoming engine build. What advantage does the Hyperspark give you if you already have your Sniper up and running?
I'm strongly considering the Sniper setup for my upcoming engine build. What advantage does the Hyperspark give you if you already have your Sniper up and running?
More accurate timing control and the ability to change your timing curve with a laptop. You can also tune a lot better and theoretically gain more horsepower and better gas mileage. In the spring I'll let you guys know how I like the new distributor
10-15-2020, 11:24 AM
Thanks in advance.
