Need help for tune / bad idle

fsxfreak1992

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I swaped from a stock Eaton to a GEN1 2.3L Whipple and installed a Return Style Fuel System during winter and a 200A Alternator with Big 3 wire upgrade.
I´m doing a remote tune with a very well known men
My tuner send me a idle tune according to my modifications. It starts normally but after ~30 sec it idles bad.
93 Octane Tune should be good, so it must be some mechanical /physical issue

Here a short idle video (at the beginning and end I manually hold the RPM to around 1k RPM)


What I have done so far:
- checked all vacuum lines, used leak detection spray around the blower --> no leaks
- Fuel Pressure is set to 40 PSI (according to gauge on fuel regulator and FRPS(read out via SCTX4))
- No fuel in vacuum lines from FRPS and vacuum line from regulator)
- Unplugged FRPS --> no change
- I pulled the spark plugs, three of them looked little wet
- filled the fuel tank with fresh 93 octane fuel (no boosters used)

It showed me 4 codes
P 0406 and 0403 --> both EGR related codes, I forgot to tell my tuner that I removed it
P2195 and P 2197 after the engine died by itself --> O2 sensors showed engine was to rich but why?

My mod list (engine wise):
- GEN1 2.3L Whipple with 3" pulley
- Return style fuel setup with ON3 Hat, 2x 320lph pumps, Fore Fuel Regulator, Dash8 feed, Dash6 return, Stock Rails, 60lbs Bosch Injectors (flow tested and cleaned before install)
- New NGK spark plugs gapped .028
- JBA Shortys, Magnaflow X-Pipe with 200 Cats, SLP Loudmouth II
- EGR Delete
- Cooling Mods (170° Reische thermostat, LFP Heat exchanger, head cooling mod)
- 200A KMJ Alternator with Big 3 Wire upgrade
- Upgraded double bearing Idlers, Roush Tensioner, Snub Idler

All the help is appreciated
 

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01yellercobra

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What throttle body are you using? If it's aftermarket did you set the stop and adjust the TPS?

Was this the first revision? If so send the log to your tuner. It probably just needs adjustment.
 

fsxfreak1992

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It's a aftermarket throttle body from LFP. The endstop I tried to adjust little that it will idle at 800 RPM.

TPS hasn't been adjusted yet.

Log has been sent to the tuner. With Idle and up to 2000 RPM's
 

01yellercobra

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For the throttle stop I datalog the IAC duty cycle and adjust it until it's about 30%. The ECU will adjust to the commanded RPM. Don't use the stop to adjust the idle RPM. Things will never work right that way. Once that's done I adjust the TPS to read .97-.99.
 

fsxfreak1992

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For the throttle stop I datalog the IAC duty cycle and adjust it until it's about 30%. The ECU will adjust to the commanded RPM. Don't use the stop to adjust the idle RPM. Things will never work right that way. Once that's done I adjust the TPS to read .97-.99.
Thanks I will try that tomorrow!
Then I know the throttle body is no issue anymore
 

fsxfreak1992

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So guys the settings were way off. TPS is set now to .97
For the IAC I managed to get it slowly down to 23% (I can try to get it little more up)

Idle was better now! Little to high with ~950-1000 RPM´s but it´s only the first revison of the tune and I still don´t know do I have any other issues.

But when I went little on throttle and let it go again the RPM´s were falling just slowly and then the car went back to the bad idle and died finally (seems to run to rich). I noticed the IAC duty cycle was with higher RPM at 64% and stayed somewhere there in the bad idle.

I have two used IAC I tested and both showed similar symptoms (does it mean both IAC are shot?)
 

03cobra#2

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Is your tuner going by your short term fuel trims or are you using a wideband to log air / fuel? You say it MAY be running rich. You really need to know exactly what the af is. A good tuner should be able to get idle and part throttle correct with a few revisions.
 

01yellercobra

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So guys the settings were way off. TPS is set now to .97
For the IAC I managed to get it slowly down to 23% (I can try to get it little more up)

Idle was better now! Little to high with ~950-1000 RPM´s but it´s only the first revison of the tune and I still don´t know do I have any other issues.

But when I went little on throttle and let it go again the RPM´s were falling just slowly and then the car went back to the bad idle and died finally (seems to run to rich). I noticed the IAC duty cycle was with higher RPM at 64% and stayed somewhere there in the bad idle.

I have two used IAC I tested and both showed similar symptoms (does it mean both IAC are shot?)
Don't change anything else unless your tuner tells you. Leave it alone. I'm sure he has some changes to make.
 

cj428mach

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Sounds like something is way off and when it goes to closed loop it runs poorly.
 

fsxfreak1992

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Hey guys,
I ordered some Throttle Body cleaner for the IAC to make sure it´s clean inside.

The idle is better now but still sometimes it struggles with Idle. Today I found another interesting thing, which I think leads me to a Vacuum leak somewere! Here a Video of it:


Sorry the gauge is in Bar here quick conversion:
0.2 bar = 6 hg
0.4 bar = 12 hg
0.6 bar = 17,5 hg

You can see as soon when I go in the direction of little boost, it may runs better Idle after this.

What you guys think? Pull the blower and check everything?
 

DSG2003Mach1

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What you guys think? Pull the blower and check everything?
I still think you need to stop screwing with things until the tuner sends you a revision and go from there.

I had my combo running perfect, lost the motor to an oil pressure failure. I had it rebuilt, dropped compression a tad. Damn car could not find it's idle, hunting all over the place etc... I assumed it must have been vacuum leak or something, finally sent the tuner a log, he made a few tweaks and it was perfect
 

fsxfreak1992

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Update:
It was a vacuum leak...I bought the blower used from facebook.
I did not have the EGR, so no need for the bracket.
After I sprayed with brake cleaner around all the possible spots for a vacuum leak, I found this two screws which are open to the inside of the blower...I didn´t knew that.

After I went back to the base tune, the engine was already really good
20220331_175929.jpg
 

01yellercobra

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I had the same issue with my blower. I had done the EGR delete while I was waiting for the ECU to be fixed. Imagine my surprise when the car ran like crap first. I found those because I ran my hand by them and felt the suction.
 

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