TPI Idle issue
Hi all, need your assistance. Sorry for the long post but I want to provide as much detail as I can. I have an early 2000's GM Performance motor (880 block) with a TPI setup. I had disassembled the engine about 7 months ago, changed the rod bearings and bumped the cam up slightly. The motor was running fine with an updated prom before installing the Fitech 38350.
After the install, I just can't get this thing to idle correctly. With EST disconnected the idle is smooth. Once I connected EST idle is all over the place. I don't have a vacuum leak, FP at the rail is at 47, timing is set at *12 BTDC by a timing light and the handheld. Rotor and cap are good, along with fresh plugs. Camshaft selection is set at 1 due to map readings and I have tried setting rpms from 750 to 900 with no change to idle.
I did note when going into Loop Rate Up it was maxed out (60) I adjusted that to 35 and Loop Rate Down to 33 with no change in idle quality.
Any suggestions? It does make me wonder what other default values are out of sync.
IAC steps are between 3-10 when the idle is steady.
Loop rate up and down won't affect the idle stability. I would suggest putting those defaults back.
When you say it won't idle correctly, is it surging or not coming to base idle?
A datalog of the idle would be helpful. Log should be above 170 degrees on the handheld and no more than 2 minutes long.
What is the preferred upload format?
Idle surges as you will see from the log, it never really stabilizes.
Uploaded files:- You need to login to have access to uploads.
In this log, your coolant never gets over 170. This can cause issues, but not for this symptom.
Your Driver AFR is getting a lean reading. Your Passenger AFR sensor looks to be non existent.
Make sure you are running single O2 settings. Also check your exhaust manifold gasket, collector gasket and O2 sensor fitting. You are sucking in fresh air somewhere creating a lean reading. This will confuse the ECU and cause it to add too much fuel.
Also check your injector settings. Make sure they match the flow rate of your injectors.
Thanks Alex. I obviously sent the wrong log as I had changed the thermostat out to a 180*. I'll run another log and check the gasket at the flange.
I am only running a single O2 sensor for this kit. Is there an area to disable the passenger sude?
Thanks Austin. I sent the wrong log as I had changed the thermostat out to a 180*.
Are there settings on the handheld to disable passenger O2 sensor and injector flow rate? I am using 22lb injectors in the handheld even though the flow rate is greater.
I know the drivers exhaust flange us not straight and I already have a double gasket installed but I will check that again.
I really appreciate your clear direction.
*updated log
Uploaded files:- You need to login to have access to uploads.
That looks better. AFR is near the target now.
Look for Dual/Single O2 settings videos.
Your trim (short term learn) is maxed out. You learn (long term trim) has done nothing.
If you feel comfortable, you may need to let it set and idle for a bit, until you see some learn. Also must get your basic settings correct to the components on the engine. Flow rate, etc
I made the change to single O2 with no real change. I did yet another smoke test with no evidence of a vacuum leak. I purchased an infrared gun and noted a difference in the CTS reading and the handheld value. I downloaded the updated CTS calibration procedure from your site and began the process. The CTS never read above 1.6v and the temperature value was to low (106.2) to update the handheld table minimum value (140).
Have you run into this?
I spoke with one of their reps today and she requested an email to the tech team but it sounded as if she was a bit baffled as well. Needless to say the vehicle is not going into closed loop. She did request a resistance value for the sensor and it read .402.
I'm waiting for the vehicle to cool off to have a look inside the radiator. There is no water in the oil.
Happens from time to time, especially if using the factory sensor. If you do decide to change sensor, get a Delco.
FYI, better to call tech