Sniper 2gc small bore, large bore, or 2300?

[Ralph3]

Help. I have a Frankenstein engine in my 69 Land Cruiser. An F.5 block (F but in the last half of 1974 with the new oil circulation method) with a 2F head and a 2F manifold (2bbl). I started with a 2300, but could not find an adapter. Sent that back and got a 2GC Large Bore. That fit the manifold and the air filter, but it just flooded the engine unmercifully. 10 seconds on the starter and gas was pooled below the EFI. There were a few times I could get it to run for only short periods, never getting through the learning cycle. Thinking I needed the Small Bore, Summit Racing was kind enough to send me a 2GC small bore. Not even close to fitting the manifold or stock air cleaner.

I'm beside myself. I have scoured the internet to "my 2GC is flooding," and it seems this is not uncommon, but I cannot make it work. Where to go from here? I need to ship one back to Summit next week.

Thanks
Ralph

 

[Skreddy]

Something isn’t set right or it’s a bad unit out of the box.

The 2GC or 2300 are just fine for these engines. They are rich from the factory but not that rich.

Did you start with a good running and sound engine to begin with or did you have running issues and did efi hoping it’d fix it?

What do you mean “10 seconds on the starter” and it’s flooded. You shouldn’t need to crank it for 10 seconds; not even 3 seconds. And it won’t get into learning until 160 degrees coolant temp.

So;
Did you start with a good running engine? Timing, vacuum reading where they should be and no vacuum leaks, etc?
What settings do you have the sniper set to?
Whats your fuel pressure?
What’s your tank and pump setup?
How’s your exhaust?
Where and what angle is your O2 sensor?
Where are your sniper power and ground wires connected?
How much non stock electrical stuff is going on?


When it does run:
What rpm is it running?
What’s the MAP?
What’s the IAC?
What’s the AFR?

 

[Ralph3]

Something isn’t set right or it’s a bad unit out of the box.

The 2GC or 2300 are just fine for these engines. They are rich from the factory but not that rich.

Did you start with a good running and sound engine to begin with or did you have running issues and did efi hoping it’d fix it?

What do you mean “10 seconds on the starter” and it’s flooded. You shouldn’t need to crank it for 10 seconds; not even 3 seconds. And it won’t get into learning until 160 degrees coolant temp.

So;
Did you start with a good running engine? Timing, vacuum reading where they should be and no vacuum leaks, etc?
What settings do you have the sniper set to?
Whats your fuel pressure?
What’s your tank and pump setup?
How’s your exhaust?
Where and what angle is your O2 sensor?
Where are your sniper power and ground wires connected?
How much non stock electrical stuff is going on?


When it does run:
What rpm is it running?
What’s the MAP?
What’s the IAC?
What’s the AFR?

The engine is a fresh rebuild, 30 over. It was a siezed engine. EVERYTHING, crank, cam, and valve train all sent out and remanufactured, new valves, bearings, pistons, and oil pump. Ran fine with a Carb.
Vacuum was a tad light, about 18 at 1k rpm. Timing is 7 degrees BTDC. I'm using a Davis DUI distributor, which suggests advancing it even more, but when I try that, the engine bucks.
Fuel pressure is off. 64# when the pump is running, 54# after it shuts off. The install manual sez it is set at the factory at 58#.
Tank is under pass seat, return is on top per the install diagram and the pump is under the floorboard, against the drivers side frame (below the lowest point of the gas tank).
Exhaust is stock, bought it all in one purchase, 2 pipes, and muffler are all new.
The 02 sensor is on a horizontal section of exhaust pipe below and behind the motor at 10 degrees per instructions. Its before the muffler. Exhaust exits the left side behind the left rear wheel. No leaks as far as I can tell.
Sniper wires directly to the battery terminals.
No alerts on the handheld, although I occasionally get a low battery voltage warning.
MAP, IAC and AFR on the hand held all show normal. No yellows or other indications of something wrong.
When it was running, and did start the learn (>160), the RPM stayed between 1,000-1,100. Despite being set for 650 per my engine manual.

I've been working on this, off and on, for a year now. A lot of my time recently has gone to other things - not engine related. The cruiser was pretty much a barn find, left in a field on the Oregon coast for some years after the engine seized. So, there is a lot to do. I'm rewiring the whole harness, have replaced all the lights except the front parking lights (on a 69, remember). I've added the fore and aft side markers, later model turn signals, repairs to the hard top, rebuilt the rear door opening mechanism and most recently, installed the door stops on the front doors and rear view mirrors. Lots more to do, too.

The large bore is the mate for the manifold, no question, and I will send back the small bore. As far as the flooding goes, when it does idle for short spans of time, I can look down the throat and see the fuel is not being atomized. I suspect low pressure (54#). Not spraying, just pouring onto the throttle valves. As it pools under the EFI, it runs worse, smokes black and dies. I have gone through the 2GC full installation manual (not just the quick start guide) many times. I've downloaded the software from Holley but haven't used it yet. I found an article with 7 solutions for Holley EFI flooding where you change certain settings in the program, but I have not ventured there, yet.

Thanks for responding.

 

[Skreddy]

That’s great background and info!

Would be good to know what the MAP and IAC are at. I don’t think 4# low on fuel pressure is that huge of a deal. I would guess there’s a vacuum leak and the sniper is trying to compensate by adding fuel or, there is a setting not correct; mechanically or electronically. Also always the possibility it’s got an issue with the unit out of the box.

When you did the setup wizard did you adjust any other parameters outside the wizard like coolant enrichment, iac decay, etc?
If not, have you lowered the idle with the adjustment screw on the unit? At idle, the iac should be less than 5% and ideally, 1-2%. MAP should be in the 60 kPa range with 18” vacuum. And each time you adjust the idle screw, need to recycle the ignition to reset the tps.

 

[knuckle47]

Great suggestions @Skreddy as usual….. my thinking is are you able to get the operating temp over 160 to even determine some of these setup parameters? My initial mistake was using the IAC screw as an idle adjustment even though it sure acts like one. It took me several weeks of tweaking the IAC screw to truly establish a setting within the “guidelines”

My initial Sniper 2300 startup was text book but did idle at 1600 or so. My intuition said …lower that idle screw but not really the thing to do. The closed loop/ open loop determines when the learning takes place too… but not much will kick in until you reach that 160* mark.


This is the adapter for the 2300
@wngrog suggested sealing the mounting bolts. You can see the rtv if you zoom in

 

[Ralph3]

That’s great background and info!

Would be good to know what the MAP and IAC are at. I don’t think 4# low on fuel pressure is that huge of a deal. I would guess there’s a vacuum leak and the sniper is trying to compensate by adding fuel or, there is a setting not correct; mechanically or electronically. Also always the possibility it’s got an issue with the unit out of the box.

When you did the setup wizard did you adjust any other parameters outside the wizard like coolant enrichment, iac decay, etc?
If not, have you lowered the idle with the adjustment screw on the unit? At idle, the iac should be less than 5% and ideally, 1-2%. MAP should be in the 60 kPa range with 18” vacuum. And each time you adjust the idle screw, need to recycle the ignition to reset the tps.

After getting the Large Bore back in place and checking all the connections, it started, ran poorly, began to smoke and I shut it down. Below are the pictures of the handheld at Stall, upon startup at 706 RPM, and as it started to smoke at 574 RPM.

Made no changes outside the wizard. I realize now I had the Large Bore, but the only installation instruction I could find was the Small Bore, and the only selection available to me in the setup was Small Bore. I have never adjusted the idle screw. It only got above 160 degrees a few times, entering Learn mode.

I thought I'd try the handheld sent with the Small Bore. Surprise surprise. The software has been updated in the last year. Now, I get 2GC by the last 3 digits of the model number, so I was clearly able to select the Gold Large Bore model. Didn't seem to make a significant difference. It started, but did not reach the 1,000 RPM as in the past. It ran rough and peaked out near 700 RPM. From there, it was downhill on RPM until it started smoking and I shut it down. Acting on the vacuum, I disconnected the new brake booster, just in case. I didn't have time to look at the vacuum gauge I have mounted on the firewall.

Again, thanks for your interest, and any other advice you might have. There was about four days about 2 months ago where it ran, and ran better each day (Learning), and I was thinking the nightmare was over. Then it started to flood, again. I don't think it's a Lemon. I'm thinking its electric.

 

[Skreddy]

That MAP is SOOOOOOOOPER high, like 23-30” hg.

The idle screw will need adjustment to properly run, they aren’t good to go out of the box. I think your IAC is at 100% because it’s trying to compensate for the throttle blades not being open enough (or at all), which also may be why the fuel spray doesn’t look like a spray (not enough vacuum through throat).
I’d start by giving the idle screw 1 full turn and see what that does. You can look down at the throttle blades and see if unscrewing moves them and if not, they are completely closed.

 

[Ralph3]

SUCCESS! It runs. Got a ways to go, but it's running and learning. Thanks so much. Tomorrow, I'll be securing the harness and letting it learn.

 

[knuckle47]

@Ralph3. So what did you do differently to go from the problems you started with, to the success you mentioned above?