Bad TPS?

[Mr Impala]

Greetings all. I've been running the Sniper EFI on my car for a couple years now. I decided to upgrade to the HyperSpark distributor, coil, and CDI box. Seem pretty straightforward. Installed everything, and no start. Did all the troubleshooting from the instructions and this forum, and then contacted Holley. Hint: Call them at 8:00 am central time and you won't wait very long. Anyway, it was decided the Points Output wasn't...putting out. The ECU was bad. Off to Holley.

After about two months, I just got it back yesterday, dropped it back on, and made all of the connections, tried to start and no fire. After checking all of the connections, I noticed that the TPS readout on the handheld was reading 100.1%. That ain't right. Checked the plug to the TPS and it seemed OK, but I removed it and clicked it back in. The handheld read 0.0% for the TPS. Sweet! Then it fired right up.

I then checked/set the timing, and it just shut off. Started a couple times and I noticed the TPS readout was normal 0.0% until it stalled. It went red. It would stall after about 30 seconds or so. Then I started it and revved it to about 2500 RPM. The TPS pretty much followed my foot. Then it tried to die, but I played with the throttle to keep it running, and the TPS was red and jumped down into negative numbers and just jumped all over the place, of course my foot was jacking the gas too, but then it started popping and I let it shut down (stall). What do you think, TPS bad? Thanks, in advance, for any and all help. Kurt

[Danny Cabral]

Originally Posted by Danny Cabral Sniper EFI Replacement Sensors - Auto Parts Store CTS Sensor: Standard Motor Products TX3 TPS Sensor: Standard Motor Products TH191 IAC Motor: Standard Motor Products AC416 WBO2 Sensor: Bosch 17025, 0258017025 (LINK/LINK/LINK) (The Sniper EFI 2 bar MAP sensor is internal with the ECU. The Sniper EFI IAT sensor is a circuit board sensor that measures one throttle bore.) Innovate Motorsports HBX-1 Heat-Sink Bung Extender is great for protecting the WBO2. https://www.holley.com/brands/holley...ce_components/ (Sniper EFI Service Components)

[GPatrick]

Download the Config File from the Sniper so we can see your timing setup, 2D Table or Simple settings.

Turn on the ignition, start a datalog, and start the engine. Collect data at warm idle for about 30 seconds. It would be helpful if you could catch it when it shuts off. All we need is a pure idle with no throttle input.

Zip the Config File and datalog files and upload them here so we can see what's going on.

Your symptoms sound like you may be experiencing EMI/RFI interference and it would be best to check for this before replacing any parts. EMI/RFI can produce a number of symptoms such as erratic TPS signals/operation. Check your plug wires and coil to ensure that they are separated from any Sniper wiring. Also make sure you have entered the correct parameters (Reference Angle and Inductive Delay) for the distributor. If they're not correct you can end up with rotor phasing problems that can generate significant EMI/RFI. Pull your distributor cap and inspect the posts and the rotor for any signs of excessive arcing.

We'll know a lot more after we see your Config File and datalog.

[Danny Cabral]

Forum members will want to see your Config File and a Datalog of this occurrence. Global Configuration Files (GCF) and Datalogs must be "zipped" (compressed zipped folder) in order to attach directly to a forum post ("Upload Attachments").

Originally Posted by Danny Cabral For further assistance, post your Config File and a short datalog of this occurrence for us to analyze. Also, review the datalog and inform us of exactly where in the datalog (time/seconds) the problem occurs. Datalog & Global Files can be linked to a document hosting website. I use Dropbox.com. Files can also be "zipped" (compressed zipped folder) & attached directly to a forum post ("Upload Attachments"). Your Config File is in the "Documents", "Holley" folder, "Sniper" folder, "Config Files" folder (.hefi file). Your Datalogs are in the "Documents", "Holley" folder, "Sniper" folder, "Data Logs" folder (.dl file). Someone will analyze/troubleshoot the problem & offer advice. https://www.youtube.com/watch?v=iqHOtDNiTNA (How To Record & Email A Datalog) https://forums.holley.com/showthread.php?21942 (Holley Sniper EFI Save GCF On SD Card & Laptop/PC Usage, LINK - Page 73)

Overlay the datalog onto your Global Config File (GCF), and pay special attention to the center paragraph in blue print:

Originally Posted by Danny Cabral Quick Datalogger Information: Always provide data, not just symptoms. Is the AFR & ignition timing optimized? Overlay the datalog onto your Global Config File. Ensure the Target A/F Ratio table is properly programmed for your engine. Ensure the ECU is "Learning" (Learn Table LINK). Scroll through the datalog to the problem area. Then look exactly where this happens on the Base Fuel & Timing Tables. Scrutinize: RPM, MAP, MAT, TPS, CTS, IAC, Target AFR, AFR Left, CL Comp, Ignition Timing, Duty Cycle, Fuel Flow, Fuel Pressure & Battery. Using the Holley EFI software (LINK), look at where the live cursor moves to during this occurrence, and manually tune that area of the Base Fuel Table (enrich or lean) & Base Timing Table (optimize ignition timing). I find the most helpful datalog function, is overlaying the datalog on your GCF. I'm in the habit of using the datalog Overlay feature every time I review a datalog. Click on "Datalog" (on the top Toolbar), "Activate Overlay", then "Open Data Log". You can literally "playback" a recorded event, and watch it as it happened on any screen. Minimize (shrink) the datalog window, and move it to the bottom of any GCF screen. Then click & scroll anywhere on the datalog, and watch it playback on your GCF (EFI software). http://documents.holley.com/techlibr...9r10543rev.pdf (Holley EFI Datalogger Instructions) https://forums.holley.com/showthread...s-amp-Datalogs (Datalog Information - Read "NOTES") https://www.youtube.com/watch?v=iqHO...C6FEA0BB99AF17 (How To Record & Email A Datalog) https://forums.holley.com/showthread...7531#post77531 (Closed Loop Datalog Tuning - Posts # 2, # 4 & # 6) http://forums.holley.com/showthread....2523#post62523 (Read 4th & 5th Paragraphs - Smooth Fuel Graph After Transfer Learning)

[Mr Impala]

Should the Idle Spark box be checked, and are the P & D good numbers?


GCF and datalog is, hopefully, attached. Not sure if needed, but the engine specs are: Chevy 355, stock iron 1.94/1.50 heads, flattop cast pistons (9.8:1), cam card not nearby, but in the area of 230° duration @ .050 split duration (Jegs), Weiand dual-plane intake with the divider cut down a bit, 160° thermostat, and a 1/4 inch 4-hole phenolic spacer. Thanks again, Kurt

GPatrick: The distributor was installed according to instructions. The plastic cap fell into place and it was pointing to number 1. Did I mention the engine runs great, until the TPS reading goes nuts? I means it revs great and everything. Reference Angle was kept as it was in the instructions, Holley EFI software, and the handheld: I believe 57.5°. The Inductive Delay was adjusted to 120 usec. The timing light timing was adjusted once the engine started and the advance set to 15°. I think I had to adjust it about 2° to match the 15°. At 4000 RPM the timing moved a bit, so the Inductive Delay was adjusted to 120 from 100 usec, and it matched.

[GPatrick]

Are you running boost? Your tables are setup for boost, but you didn't indicate in your first post. Yes, Idle Spark control should be enabled. You're running somewhat lean, especially if you are running boost in the WOT region.

What is your current redline for your combo?

Your datalog is showing negative time numbers and you can see the reset. At the reset the TPS signal spikes to nearly 600% which is part of the reset. You'll need to start looking at your wiring and the placement of your plug wires and coil. It sounds like you did a proper install of the distributor, but I'd still inspect the rotor. You mentioned that you set the Inductive Delay to 120, but in the Config File you posted it's still set to 100 usec.

[Mr Impala]

GPatrick: No boost. I'll get the Idle Spark control checked and reset the Inductive Delay to 120 usec. I just noticed that, also. I set the redline to 6000 RPM.

The cap & rotor look good.

I did have the coil wire running a couple inches perpendicular to the a group of Sniper wires. I rerouted the coil wire up and in front of the brake booster.

I'll install the new setup in, run it and take another datalog. I'll start it while I'm warming it up, as I keep it at about 1500 RPM to about 170°F until it tries to stall and I'll keep it running. Then I'll do another datalog as it's idling warm and attach them to a post. See ya in about 30 minutes. :)

[GPatrick]

You should probably run a new Wizard to get a basic tune into the system that's for a N/A engine. I'm finding other issues related to your enrichment Blanking values that are hurting your Closed Loop setup and more. The Target AFR values and your Base Timing Table need some work as well. Are you comfortable working with the EFI software? I normally don't recommend re-running the Wizard, but it'll save time to improve a Wizard tune compared to trying to fix the Config File you have.

[Mr Impala]

Huh, guess it was closer to an hour. So I had some issues getting it to stall, kinda. It wanted to stall while warming up, which you'll see in datalog 17. During either 18 or 19, it tried to stall, but again I tried to keep it running, then it backfired through the exhaust, my ears are still ringing. During 20, I let it idle and hit the throttle at a little past 80 seconds, then let it idle again. It did not try to stall, I shut it down.

Let me know you see, and any suggested adjustments. Do you suggest that material to block RFI, Faraday tape, or something like that? Thanks, Kurt.

[Mr Impala]

The Base Timing Table is just there. I haven't been able to drive the car. Are the Target AFRs really that screwed up?

[Mr Impala]

I just changed the AE vs MAP Rate of Change from 7.0 to 15.0, as suggested in the Help section of the EFI software. Haven't tried it yet, just trying to go through the Config File right now.

[Danny Cabral]

Read link: The Holley Sniper EFI will intermittently inhibit Closed Loop at idle, if the AE vs TPS/MAP RoC Blanking values are set too low (LINK).

[Mr Impala]

According to the "Help?" in the Holley software, the AE vs TPS RoC Blanking should be, or at least start at 7 and the AE vs MAP RoC Blanking should be/start at 15. My AE vs TPS is/was 7 and the AE vs MAP was 7 and changed to 15. Are those numbers appropriate?

[Danny Cabral]

The Help manual is outdated. That's why I posted the link.

[Mr Impala]

There isn't a starting point for the AE vs MAP Blanking? Any suggestions? Go back 7? 20?