Dirty_Duke

iTrader: (1)

I've got a 1991 305 tpi formula that usually seems to run perfect when cold. When it is hot for more than 20 or so minutes or after running it hard it starts to have high idle and idle issues like when in neutral at a light (it's a 5 speed) it will sometimes drop to 400 rpm and sputter then spring back up to 1100 rpm and hover there and sometimes pulse between 700 and 1k rpm. It will also sometimes be really jerky when you let off the gas and coast in gear. Its intermittent and it has no issue with power unless it stalls and reverts to limp mode and fuel pressure seems fine about 35 psi with the vacuume line connected. Has new tps, iac and adjusted both and has new cap rotor wires icm and ignition coil the rough idle triggered a code 33 but I double checked the map sensor and connector and they where fine and i changed them with an OEM ac delco map to be safe. Also has new ecm. So I'm looking for some advice on how I can fix my issue with my iac going wild when hot, I can try to get some live data but I'm having a bit of trouble with tuner pro. Thanks for any answers I'm so stumped!

Dirty_Duke

iTrader: (1)

Also Google drive link to a video of the pulsing idle in action: https://drive.google.com/file/d/1AiX...w?usp=drivesdk

KyleF

You answered your own question... I think the first step here is get your datalogger working. It is about the only way to catch an intermittent problem.

I agree it does sound like the IAC is going wild, but is the ECM telling it to do it? There are functions built into the tune that tell the IAC to open as you are decelerating and such to smooth the transitions. Are you sure the passage and seat are still clean?

Could be false knock causing your timing to jump around.

Could be slack in the timing chain causing timing to jump around as well.

It never hurts to do a minimum idle set procedure. It is free, and gives you the opportunity to check and monitor your timing and confirm IAC setting. Your TPS on an SD car is not as important unless it is throwing completely erratic signals - you would see this on a datalog. .

It would also be beneficial to see what the ECM is receiving from the CTS.

Another thing to check is smooth function of the throttle body itself. Is it not always fully returning? Are their any leaks around the shaft?

Dirty_Duke

iTrader: (1)

I went and got some tb cleaner cause my passage looked kinda nasty and I'm trying to get tuner pro running but it won't display gauges in the display area. Know of any good guides for tpi f body tuner pro rt setup?

KyleF

This board...
What files are you using?
The DIY Prom forum would probably be the best place for specific questions.
I can help some, but I am using EBL that came with its own XDF file and has it's own logging with the WUD. I only logged from an 88 165 ECM prior with TunerProRT

Tuned Performance

iTrader: (92)

If da connection shows look at the item list or data monitor to verify connection. If your seeing live data your $8d adx needs a customer dash built or you need to use a adx with the dashboard already built.

Dirty_Duke

iTrader: (1)

I used the file for lb9 and l98 f bodys on tuner pro website but it had to be converted to an adx from an ads file for some reason and I verified a connection so it's not the connection. Do you have a link to a prebuilt dash adx? Cause my dadh builder wasn't working. I'd add a new gauge and hit save and nothing would show up

Tuned Performance

iTrader: (92)

http://www.gearhead-efi.com/Fuel-Inj...CM-information

can always use tp v4 with the ads