Sniper issues with idle and such.

[Brave Salmon]

I have a BPE 347 sbf with the Sniper system. No timing control, just fuel. I have had a lot of trouble getting this thing stable and thought one of you Sniper gurus might be able to help. Initially, I had fuel pressure issues and Holley sent a replacement regulator which worked fine and got pressures down to ~62psi. I have had idle speed problems continually since then. When motor is cold (50* or so), I turn key on, wait for prime and then it fires right up and goes to a very high idle of ~2400. After a minute or so it drops a bit to 1500 and when it finally settles out it is at 1000-1100. The hand held is set to an idle speed of 825 with the AOD transmission. I have done the IAC adjustment a dozen time and every time, it is different from one day to the next. Holley had me tape over the IAC hole in the top of the throttle body and adjust it again using their procedure and it makes no difference. Cannot get it to repeat from day to day. I called them again today and they are wondering if I have a problem with the temp sending unit. Since day one, this motor has had it temp rise in record fashion from dead cold to 160-170* in a matter of a few minutes, literally. I checked with Josh at BPE and he reminded me its a high performance motor that will get warm faster. BTW, ignition is set to 34* max at 3500RPM per BPE direction. The motor has ~350 miles on it and seems to perform well except for the idle problems. It still shows learning in progress whatever that means at this point I am unsure.

I am going to swap the location of the temp sensors (Sniper and original dash gauge sensor) to see if that matters and get back to Holley. Hopefully, someone has an idea how to proceed. I want this thing ready for the cruise in next month and need it to be right before I drive it 400+ miles. Ideas?
thx,
Tom

[FF33rod]

Hey Tom
Not a Sniper expert but I do have a Sniper on a non BPE 347.

Where is the location of your Sniper Temp sensor, in the manifold? (should not be at the radiator) And I assume the idle settings that you played around with were all with the engine temp above 160 (as per the idle setting instructions in the manual)

Have you tried the Holley Sniper Forum? There are a couple of senior people there that are a tremendous help.
The normal process of debugging on that forum is for you to turn logging on at the Sniper, capture a log file of the problem sequence, take the SD card out of the sniper display and take it to your PC. The log and config files can then be downloaded to the forum for the experts to have a look-see. There is also free Sniper Configuration software for your PC that allows you to view the files (and do a lot more configuration than possible through the handheld that connects to the Sniper).

Steve

[FF33rod]

By the way, I found a lot of good information in the manual for the PC Tuning and configuration Software. Even if you don't want to use the software, it would be a good idea to download the manual. There is an idle section starting on page 23. Look here https://www.holley.com/support/resou...Fuel_Injection to download the Sniper EFI Software Help File

[Brave Salmon]

Thank you, Steve. I have the help file on my tablet now. I've got to admit, I'm not all that impressed with the Sniper from a trouble shooting viewpoint. Holley is way to difficult to get on the phone which surprises me a bunch. I'll wait til the morning and start a data log running so I can be prepared to provide it if necessary.

Following up on your first response, my sniper sensor is in the manifold between dist. and throttle body. The dash gauge sensor is in top of t-stat. Both read closely from cold to normal running temp of 187~. Does yours get up to 160 in less that 2 minutes? Thanks for the help.

[FF33rod]

I agree on the troubleshooting. Going in I had bought the koolaid that these self learning EFI systems were plug and play but have now come to grips with the fact that to get the best out of them they actually need some human tuning (I have yet to find a local expert for that).

Mine takes significantly longer than yours to get up to that temp but I've never timed it. My engine is a bit more aggressive than the BPE one - probably around 450hp with higher compression, AFR heads and a trickflow stage 2 roller cam. Not sure I buy into the explanation that you were given.

If you get a chance to take a look at the table that defines idle versus temperature, that's where I'd start if you've followed the idle setting procedure to the letter...

[Brave Salmon]

Thanks Steve. I will time it from cold to 170 tomorrow. Also, looked at the idle speed curve and if seems OK to me. Just need the darn thing to follow the curve. Thanks to you I am on the hunt again. Simple is never simple in this field... take care. Tom

[Erik W. Treves]

You need to do the IAC setup procedure if you havent already

[Brave Salmon]

Thanks for the suggestion but I've been there and done that a dozen times. Issue is that it does not stay. I can get it to 0 tps and 3-5% iac, save it all and tomorrow it's different. Holley had me tape over iac hole in the top of the throttle body, turn up idle screw 1/2 turn and then adjust until idle is 500 below initial 1/2 turn generated rpm.

[Erik W. Treves]

not sure ,,, I missed the fact that you had already done the IAC - mine dropped right in and idled fine on 2 cars. Odd that IAC settings are not staying.. i am not sure the sensor would matter as that won't fix the IAC not remembering the setting... are you hooked directly to the battery both ground and power on the main feed wires?

[HVACMAN]

Vacuum leak?

[FF33rod]

Tom, how's it going with your idle problem? any progress?

Steve

[Brave Salmon]

Well, as everyone can understand, the damn thing is working fine two days in a row. I guess the threat of a data log dump was enough to get Mr. Sniper to work better. No sense uploading a dump that will only show it ids working properly but I will start a log each time I start it for a few more days. Thanks for all the assistance.

Hvacman, no sign of a vacuum leak. It pulling a good 16"hg at idle and I sprayed all the gasketed joints on the manifold with ether. No change in rpm so that's fine.

thx