1971 Mustang
BTW, I even increased the the torsion in the primary spring by turning it clockwise. The butterflies return with a lot of force so I would be surprised that this is an issue. Is the TPS sensor in the primary only or also at the secondary? My other question, since I don't have much experience with the log, should I be in the "idle" screen when I log?
Yes, the TPS sensor is only in the primary. After starting the vehicle I put the handheld in the "dashboard" view to view parameters on the fly and let it idle for awhile to temp, then push the black button to start the log record. Then after awhile I increase RPM to see how it responds. When done recording the log, simply push the button again and it should stop recording. Turn the engine off and let the screen go blank, then disconnect the handheld and bring it into the house to copy the log files to my computer to view in excel.
Okay. So I was finally able to check the butterflies. Evidently the butterfly of the secondary opens up slightly when the engine is at the hanging idle condition. If you tap the gas pedal or turn the engine off it then shuts the secondary butterfly completely off. The way I have it setup now, the link screw between the primary and secondary allows for a slight rotational play of the secondary butterfly Since the spring in the secondary is not strong enough, the vacuum at idle is enough to open the secondary slightly until it rotates to engage the primary. The spring of the primary is strong enough to keep the TPS at zero, but it doesn't keep the secondary completely closed due to the play. That said, I see two alternatives. I can readjust the link screw between the primary and secondary, which will leave the secondary butterfly tight with the primary, but it will also leave a small opening of the secondary. Unless there is a different way to adjust it that I don't know about it. The second option would be to add more turns to the spring of the secondary. What are your thoughts.
Good news! At least you know now what's causing the hanging idle. Now you just have to figure out a way to close the secondary. Maybe you need to put another return spring on the secondary side. Not sure without seeing the setup.
As a follow up. For some reason I had missed the secondary adjusting screw. I was able to adjust the secondaries so they move at the same time as the primary by eliminating the "play" I was referring to. I ended up adjusting the primary and secondary so to get to a 8-10 IAC at idle. It took a bit of back and forth but now I have the primary and secondary in sync together with the correct IAC. So far so good. What I don't understand is why the instructions don't mention anything about the secondary adjustment. Maybe it was all alright from factory and I messed it up at some point when I installed it but I can't remember.
Wow this is the same problem I’m having ! It’s so bad I was about to put the carb back on!
Quote from hades fastback on October 1, 2019, 10:37 amWow this is the same problem I’m having ! It’s so bad I was about to put the carb back on!
I had this problem for a while and drove me crazy. I hope you were able to fix it following this thread. This is the nice thing about this forum. Being able to look over the many different adjustment problems, software and hardware, that can play a role in how these units function. Now I am working on fixing the next issue I am having.
Quote from tony-muscle on October 2, 2019, 9:09 amQuote from hades fastback on October 1, 2019, 10:37 amWow this is the same problem I’m having ! It’s so bad I was about to put the carb back on!
I had this problem for a while and drove me crazy. I hope you were able to fix it following this thread. This is the nice thing about this forum. Being able to look over the many different adjustment problems, software and hardware, that can play a role in how these units function. Now I am working on fixing the next issue I am having.
Exactly why I started this forum. So glad it worked. Many said Forums were dead.....