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My build thread https://thefactoryfiveforum.com/show...Roadster-Build
Thread on Stainless Steel AN brake lines.
Thread on fasteners and torque wrenches.
I've questioned my O2 sensor a few times with Holley and they doO2n't feel as if it's likely the problem as the engine runs nicely during acceleration. The problems all exist under 1500 RPM, where it's a little rough and of course my surging idle. Id love to get your take on their assumption. Could a bad O2 cause these problems but otherwise perform nicely in all other areas?
Picked up kit 9/6/22. Complete Roadster Kit, IRS, 18" wheels, Forte 302, T5. First build. No auto mechanical experience and beyond excited to learn. Loaded with "Empty Nester" time and energy. Link to my build videos: https://www.youtube.com/channel/UCgX...uCWGcelzGecm1Q
Picked up kit 9/6/22. Complete Roadster Kit, IRS, 18" wheels, Forte 302, T5. First build. No auto mechanical experience and beyond excited to learn. Loaded with "Empty Nester" time and energy. Link to my build videos: https://www.youtube.com/channel/UCgX...uCWGcelzGecm1Q
Holley doesn't think it's the O2 sensor because everthing looks ok except for the surging idle and somewhat rough performance below 1500 RPM. They believe that if the O2 sensor had failed, it would be affecting performance across the entire spectrum. I'd love to get anyone else's read on that-- can a O2 sensor fail where it only affects these two problems I'm having? Is it truely an all or nothing with this sensor?
Picked up kit 9/6/22. Complete Roadster Kit, IRS, 18" wheels, Forte 302, T5. First build. No auto mechanical experience and beyond excited to learn. Loaded with "Empty Nester" time and energy. Link to my build videos: https://www.youtube.com/channel/UCgX...uCWGcelzGecm1Q
Is this the tune the car is running on or the base that Forte loaded? The learn table is all 0. Did someone transfer the learn table to base fuel? The data log shows learn is occurring so there should be data in that table.
Mk IV Roadster, 347/516 HP, 8 stack injection, Holley HP ECU, Astro Performance T5, 3-Link 4.10 gears, A/C, PS, PB Purchased 08/2015, Graduated 02/2017
So here's where my newbie stripes are going to show.
I downloaded this tune to my ECU following Forte's instructions. After speaking with Holley and making all these grounding changes, they suggested I reload the tune so that it starts learning with the new parameters, basically starting from a clean slate. If I remember correctly this data log was after driving the car for only about 30 minutes with the tune reloaded.
I hope this answers your question.
I'll also send you a personal message.
Thanks!
Picked up kit 9/6/22. Complete Roadster Kit, IRS, 18" wheels, Forte 302, T5. First build. No auto mechanical experience and beyond excited to learn. Loaded with "Empty Nester" time and energy. Link to my build videos: https://www.youtube.com/channel/UCgX...uCWGcelzGecm1Q
I think some have missed my point. The concept of the bolt on throttle body injection is wonderful and Holley's set up wizard couldn't be easier, and the setting of the basic parameters is easy as well. That being said, it should function correctly after that. I see many guys on this forum who have issues and if you go on the Holley forum there are tons of guys having issues with this product. I have talked to engine tuners who will not work on the Sniper product because of its inability to stay reliable. I think if it's an out of the box product, it should work out of the box.
FFR 9883 MKIV ,427 Windsor engine
TKX 5 speed, Three Link 3.55 gears
Power Steering, Leather Seats
18" Wheels and Tires, Drop Trunk
Fun Package
That explains the learn table then. Thanks.
Mk IV Roadster, 347/516 HP, 8 stack injection, Holley HP ECU, Astro Performance T5, 3-Link 4.10 gears, A/C, PS, PB Purchased 08/2015, Graduated 02/2017
My build thread https://thefactoryfiveforum.com/show...Roadster-Build
Thread on Stainless Steel AN brake lines.
Thread on fasteners and torque wrenches.
I gotta admit tho my Sniper 2 is still giving me grief. Been with a professional tuner going back and forth several times now. On the dyno and driving around. We think we've nailed it, runs great and then the next morning it won't idle again. Now instead of dying every time I stop it either yo-yo idles between 500rpm and 2k or just sticks at 2k. 2 days ago it was idling and returning to idle perfectly. uggggg.
MK3 Challenge Car, Boss 347, Sniper 2 EFI
Interesting I'm having the same issues and mine is also from Forte. However, The Traveling Builder did my initial tune file and now I'm with a local dyno tuner. Brenden only had about 2 hours tuning it to be fair before we loaded up and got down the road home. So it was a very basic, "it's running!" setup. With my local tuner (Horsepower Farm) we had it on the dyno for a solid day and out driving for another 4 hours. I was under the impression that it "shouldn't be this hard", but alas apparently it is. Horsepower Farm is confident that I'm not having RFI issues. I'm at a loss and just want to get back to cruising and racing instead of fiddling with idle issues at every stop light.
Last edited by john42; 04-18-2024 at 06:42 AM.
MK3 Challenge Car, Boss 347, Sniper 2 EFI
I have a Fast Sportsman system, not much experience working with a Sniper. The Fast has one quirk that I just live with. At startup I need to turn the key to the run position for about 10 seconds before cranking to start. If you just key straight to cranking, the engine just doest run quite right, almost the same symptoms you guys are talking about. Next time it happens, just pull over, turn off the engine then restart using the 10 second pause. Maybe it'll make a change?
Mrk III, 331 stroker, Borla stack injection, T5, 3:55 IRS, Power steering and brakes. Kleiner body & paint
Yep, sounds like your problem is very similar to mine-- slight hang at 2k rpm, bumpy and surging idle, and add to that temperamental low RPM performance (under 1500).
Here's where I'm at in the process-- which is basically throwing everything I can at the problem until I figure it out. By the way, I know virtually nothing about tuning so I'm attacking what I can and then seeking assistance with the tuning. I also just ordered another O2 sensor so I can rule that out-- $100 is somewhat of an expensive experiment, but one I feel I need to do.
I took Monday off to completely rewire the front of the car.
I moved all wires except the water temp, oil pressure and O2 sensor wires from on top of the engine (no options there as they go directly to the Sniper.
I moved the coil to the F panel and ran coil wires to run along the side of the engine bay and the sent the wires directly to the distributor keeping them away from the Sniper.
Ran a 2ga ground cable from the trunk mounted battery directly to the engine grounding point on the chassis (probably overkill, but Sniper suggested it)
Ran a ground cable directly from the throttle body of the sniper to the same engine ground point on the chassis.
Exhaustive IAC and Rampdown experimentation.
None of this seem to make much of a difference. I say "much of a difference" but I do feel that its running slightly better after having done what's listed above.
Last hurdle is to shield the distributor, but truthfully, I'm waiting on the new O2 sensor to give that a try first (due in today).
Like I said, I'm throwing everything I have at this--figuring I'll eventually and probably accidentally figure it out
Last edited by AA-ron; 04-18-2024 at 08:50 AM.
Picked up kit 9/6/22. Complete Roadster Kit, IRS, 18" wheels, Forte 302, T5. First build. No auto mechanical experience and beyond excited to learn. Loaded with "Empty Nester" time and energy. Link to my build videos: https://www.youtube.com/channel/UCgX...uCWGcelzGecm1Q
In a nutshell, you summed up every troubleshooting effort. You try everything until you find the issue. It hurts that you spend all that time "fixing" everything you have tried so far only to find out nothing has changed. Troubleshooting is eliminating the possibilities ultimately leaving you with the issue. Frustrating and time consuming sure, but in the end rewarding once you finally fix it!
MK4 base kit, 2004 Mach 1 donor, 4.6L DOHC, TR-3650 5-speed, narrowed stock axle with 3.55 gears and TruTrac, PS, PB, ABS, 17" Halibrand replica wheels, started 12/2011, registered 9/2014, sold 3/1/2018.
1970 Mustang Fastback Coyote powered Boss 302 tribute. Started 10/14/16.
Gen 3 Coupe Base Kit non-donor build. Ordered 4/5/2024 to be received August 2024.
Not sure who you’re using as tuners but I highly suggest Andrew. [email protected]
He nailed my former terminator X tune with lots of extra inputs, outputs, custom tables etc. I have no idea if sniper has similar controls but worth a shot. This guys is all over the LS and Holley forums.
From what I understand the SBF rev up and down so fast it makes it a tricky beast to get the return to idle right. The idle drops so fast and the sniper has to be just right to catch it. LS on the other had has a naturally slower ramp back to idle and takes less fiddling with the sniper to catch it.
I've been going to Horsepower Farm in Loudon, NH. They've got a very good rep around NH.
MK3 Challenge Car, Boss 347, Sniper 2 EFI
AA-ron, looking at your data log I don't think it is a RFI problem. It's going very lean and the engine starts losing rpm, then the ecu reacts and adds fuel opens the IAC and adds timing trying stabilize it. Those are the correct responses. So the question is why is it going lean. Bad 02 sensor or a real fuel supply issue? My point is you can see what is happening, now to figure out why. Weendoggy is sharp on tuning, do you have any thoughts, looking at the data log?
Bob
Mk IV Roadster, 347/516 HP, 8 stack injection, Holley HP ECU, Astro Performance T5, 3-Link 4.10 gears, A/C, PS, PB Purchased 08/2015, Graduated 02/2017
Ya if I blip the throttle it will settle to the desired idle. It loves to always be stuck. Do you adjust the "RPM Above Idle to Start Ramp" to be above or more below that spot. That other issue is with the engine always trying to race to about 2200 RPM when casual driving the car always wants to accelerate. Fighting the car with brakes is not good. Reminds me of a certain youtube video....
My current settings:
iac-parked.jpgidle-speed.jpgIAC-settings.jpg
MK3 Challenge Car, Boss 347, Sniper 2 EFI
Mk IV Roadster, 347/516 HP, 8 stack injection, Holley HP ECU, Astro Performance T5, 3-Link 4.10 gears, A/C, PS, PB Purchased 08/2015, Graduated 02/2017
Would suggest asking Holley to upgrade you the Sniper 2. The RFI has been addressed with the 2nd generation. Just scanning through your original post, would definitely look at the IAC Reading. Very important to keep in the 0-5% range. Of course grounding very important too!!
Looking at those settings, I'd say your Ramp Down is set too low. This means your idle will start ramp down at 1550rpm's with 0 TPS setting. So, if you have your foot resting on the throttle at say 2 and running at 1500rpm, it won't do anything, but stay where it is, which is what I'm gathering from your post. The TPS should be at 0 or maybe 1 in order for that to work correctly. Is it doing that when you have it hang? Only way to know is a datalog or you're watching it as it happens. Also check what Bob says about the throttle plates. I just got through checking my Terminator after having some similar issues recently and had to re-center the secondaries. I don't have any Sniper I've done set as low as you do on Ramp Down, but each engine is different.
Here's an update:
I replaced the O2 sensor to see if that made any difference and it unfortunately did not. So I can add O2 sensor to my above list and check that off (and now I have a spare O2 sensor .
I was able to drive it about 20 miles yesterday and noticed a slight improvement in it returning to steady idle after being on the throttle, but only a slight improvement-- and even after saying that, I'm not completely sure. However, after driving it and letting it sit for 20 minutes, and restarting it, it still surges like crazy. It drops to 200 rpm, then ramps up to 1000, and it does this over and over for the first 30 seconds. Cold and hot starts are absolutely perfect by the way. And the bumpy below 1500 RPM still exists.
This weekend we have some good weather on the way, so I intend on spending lots of time (once again) going through my IAC settings. I checked my fuel pressure again yesterday and it's still holding tight at 59, so that looks good.
While this is frustrating, I do feel better about how I've rewired the engine bay, and I'm continuing to learn more about my Sniper. I might also try giving the Wizard tune a shot, instead of the tune that came from Forte. I don't hold out much hope for that approach, but who knows...
Here's hoping soom time this weekend will shed some light on my problem!!
Picked up kit 9/6/22. Complete Roadster Kit, IRS, 18" wheels, Forte 302, T5. First build. No auto mechanical experience and beyond excited to learn. Loaded with "Empty Nester" time and energy. Link to my build videos: https://www.youtube.com/channel/UCgX...uCWGcelzGecm1Q
Have you tried wrapping the distributor with aluminum foil? If not do that and reboot the Sniper from the handheld. Any data stored or learned in the ECU could be corrupted. This was one of the first things the Holley tech had me do!
Norm
Mk4 base kit 7721, 331 Stroker, Holley Sniper EFI, Wipers, Heater, Whitby Soft Top, Drop trunk mod and more
Simple advice, don't start changing multiple items without doing a datalog to backup your change. You can make several changes and make it worse, or better, without knowing what the cause is. Ex: if it drives good and data shows good, file that tune away. If it then starts as you say and stumbles, that's when you want to start a datalog (prior to starting) and let it capture what's happening. You may find it's simpler than you think. Yes, a lot of time taken, but you find out what is causing it and you can target the area in question. If the engine is "hunting" I'd shut it down, clear the Learn Table (you already saved the tune) and then start up again and let it collect data while logging. Also, running a bad tune will make your LT look bad and you should never transfer that data becaues you'll skew your Base Fuel and really make your head spin.
On a warmed up engine and it's stumbling like you say, put it in Open Loop, start a datalog and watch fuel via the LT. Let it go through its quirks, and be sure to stop the datalog before you turn the engine off or you'll lose the log. btw: the Wizard tunes aren't the greatest either. jmo
I doubt this will help, but might jog someone's memory and the solutions.
All your issues are identical to the hot rodding of the Ford 5.0 push rod engine of the late 80's and 90's.
It's crazy the problems and descriptions are the same.
Problems began when the air filter system and or intake were changed. A cam really upset the cart.
Those who could tune the ECU's were in high demand.
Ford had a plate with adjustable air bleeds that went between the throttle body and the intake to smooth out some of the hunting idle issues.
On the TPS's the Ford's target numbers were .89 or .99. Tuners recommended the lower number, due to .99 going over 1.0 when things warmed up and moved around slightly.
I thought the EFI in question was a Sniper II. I am surprised anyone bothers with the problems of the Sniper.
20th Anniversary Mk IV, A50XS Coyote, TKO 600, Trunk Drop Box, Trunk Battery Box, Cubby Hole, Seat Heaters, Radiator hanger and shroud.
I have a throttle body fuel injection, Holley, that the injectors would leak, after a hot engine shut off.
When I would try to restart after a short time the engine would be flooded.
I wonder if you can bleed the fuel pressure off, after shutting down the hot engine. You should have a schrader valve somewhere. If so, you can wrap a rag around it and bleed off the line pressure.
My theory is, fuel is building up in the intake, creating a rich condition and the O2's are responding to this condition.
Just shooting in the dark, hoping it helps.
good luck,
20th Anniversary Mk IV, A50XS Coyote, TKO 600, Trunk Drop Box, Trunk Battery Box, Cubby Hole, Seat Heaters, Radiator hanger and shroud.
Ron,
Do yourself a favor and disable the "Idle Spark". Then take your car out for a drive and see if it improves. If it doesn't then it cost you nothing, put it back and carry on. If it does then you have a very similar IAC setup (or design bug) as me and you can then beat up Holly to figure out why.
MK4 #10008 - Ordered 10/06/20, Delivered 03/03/21, First Start 7/22/21, First Go Kart 7/24/21
Paint by Metal Morphous 5/14/22, Legally registered 6/8/22, Graduated 7/20/22
Build Thread https://thefactoryfiveforum.com/show...been-delivered
Complete Kit, Ford 306, Sniper/Dual Sync, T5, Hydraulic clutch
Thanks everyone! It feels good to have some ideas to run with! I'll drop you all a note after a weekend of driving and testing.
Picked up kit 9/6/22. Complete Roadster Kit, IRS, 18" wheels, Forte 302, T5. First build. No auto mechanical experience and beyond excited to learn. Loaded with "Empty Nester" time and energy. Link to my build videos: https://www.youtube.com/channel/UCgX...uCWGcelzGecm1Q
Post data logs and global files. With a bunch of eyeballs on it I bet we can find something.
Bob
Mk IV Roadster, 347/516 HP, 8 stack injection, Holley HP ECU, Astro Performance T5, 3-Link 4.10 gears, A/C, PS, PB Purchased 08/2015, Graduated 02/2017
Ya man you’re just wasting your time here, no offense to anyone. Send the log to a reputable tuner. Email Andrew like I suggested the tune and just see if he thinks he can figure it out first. No cost to you probably, the guy will then do a remote login to your computer and tune from there in real time while on the phone with you.
I disabled the Idle Spark and it didn't make any difference (actually ran worse I think), so I'm officially throwing in the towel.
I stopped into a local speed shop (EFI Motorsport in Somersworth NH) to have a chat with them, and was please to find them working on several cars with Snipers. After a conversation he STRONGLY suggested I buy the full Hyperspark Ignition system including the distributor. I was on the fence about that, but he said, and I quote, "I have never had a car that I couldn't fix when the Sniper and the Hyperspark Ignition system are installed". And I guess it makes sense, I've come this far with the car (new kit, new crate motor...etc) to not take it that one step further.
I'm going to be installing the new system this week and then bring it to them early next week for a tune!
Oh, and it's worth noting that he wasn't trying to sell my a Hyperspark system...
With any luck, my next post will be nothing but happy face emojis.
Picked up kit 9/6/22. Complete Roadster Kit, IRS, 18" wheels, Forte 302, T5. First build. No auto mechanical experience and beyond excited to learn. Loaded with "Empty Nester" time and energy. Link to my build videos: https://www.youtube.com/channel/UCgX...uCWGcelzGecm1Q