ECMlink new engine surging at 2-3k rpm

[Sam's GSX]

I just started my new stroker engine, it shoots up to 3k rpm, held for a good few seconds, switched to closed loop and started bouncing between 2 and 3k rpm, if i tap the gas it goes up and holds for a second before falling slowly back to 2k and bouncing.

Here are the logs, i started it 3 times,

Let me know what you guys think, I believe it has to do with the 1g throttle I put on, maybe the cables are not adjusted right, but I'm not sure at the moment.

Any help is much appreciated, thank you

 

[92AWDHX40]

How to fix your idle surge problem. | DSMtuners
i would start here for any idle issues, surge, issues.

 

[Sam's GSX]

Ok great, i have a handful of things to check tomorrow, I'll post back with the situation after.
Thank you

 

[1990TSIAWDTALON]

Throttle cable have slack?
Idle STOP switch working or simulated?
TPS manually adjusted to .063-.065?
Base timing 5*?
Biss Screw has good oring and adjusted?
The throttle stop is probably needing adjusted so it will idle down. Just a few things to check.

 

[Sam's GSX]

Awesome thank you

 

[Vegas Smith]

Your TPS is not set correctly and is tripping the idle position switch when the throttle % goes to 2%. This causes the ecu to add fuel, raising the rpm causing the ecu to add more fuel. You get the point. Adjust the throttle so that resting it sits at 0% and you'll be good. You can see this behavior at 19 seconds in the log.

 

[Sam's GSX]

Oh I gotcha, I'll do that. thank you

 

[Sam's GSX]

Throttle cable have slack?
Idle STOP switch working or simulated?
TPS manually adjusted to .063-.065?
Base timing 5*?
Biss Screw has good oring and adjusted?
The throttle stop is probably needing adjusted so it will idle down. Just a few things to check.

i realize now those were questions now and not things to check.
i did do all those things, but as of now i have back off the idle screw, and put slack in the throttle line to try to pull the idle down from 3k, (read my next post for more about your questions)

 

[Sam's GSX]

ok, update time. i have since started it a few times, 3 days ago i let it idle for longer, like 12 minutes or something, i have done a handful of things, started to make a little bit of headway today.
i have: adjusted the idle stop screw, the throttle slack, checked the isc motor for proper resistance, and checked the isc o ring, removed and replaced the biss screw, today i way idling and messing with the tune, i was able to get it down to lower rpm (1300 ish) and it was not surging, BUT, something i noticed 3 days ago is the isc position in link goes all the way down to 0 over a few minutes of idle, i have adjusted the biss screw and it doesnt change the number, however, with the new screw it does change the idle when i adjust it, i have to screw it all the way in though to get a low enough idle, now for tuning, i have added about 350 deadtime (on stock injectors) to try to get afr off of 18-20 to 14-15, i also lowered the maf comp to pull the idle down to 1300, these are mostly band aid fixes, thats not how i plan to dial in the idle.
here are 2 logs from today, i believe the "5" one is where i was adjusting stuff mid log, any help is appreciated, thank you

 

[Sam's GSX]

ok, update time. i have since started it a few times, 3 days ago i let it idle for longer, like 12 minutes or something, i have done a handful of things, started to make a little bit of headway today.
i have: adjusted the idle stop screw, the throttle slack, checked the isc motor for proper resistance, and checked the isc o ring, removed and replaced the biss screw, today i way idling and messing with the tune, i was able to get it down to lower rpm (1300 ish) and it was not surging, BUT, something i noticed 3 days ago is the isc position in link goes all the way down to 0 over a few minutes of idle, i have adjusted the biss screw and it doesnt change the number, however, with the new screw it does change the idle when i adjust it, i have to screw it all the way in though to get a low enough idle, now for tuning, i have added about 350 deadtime (on stock injectors) to try to get afr off of 18-20 to 14-15, i also lowered the maf comp to pull the idle down to 1300, these are mostly band aid fixes, thats not how i plan to dial in the idle.
here are 2 logs from today, i believe the "5" one is where i was adjusting stuff mid log, any help is appreciated, thank you

these were done with the throttle plate al the way closed, it just feels like im getting to much air, and i dont know how to combat that

 

[miguelmcv]

You have a big leak, make sure the throttle body is not damage.

I know it sounds odd but is the booster vacuum hose hooked up?, I put my 2c on a leak in the throttle body are

 

[Sam's GSX]

Ok, I'm going to do another boost leak test, you're probably right, I've looked hard for a leak, if the brake booster is the large line right past the tb, then I just double checked it, it looks fine. When I did the boost leak test 1 week ago, I had a large leak coming from my greddy type rs bov, which sucks because it wasn't cheap, and for it to leak pisses me off, the leak is coming through the bov from the intercooler pipe, and doesn't change if I pull the vac line, I just swapped to my 1g bov to fix that leak, started the car and now it revs even higher, as if fixing that leak gave it even more air. I'll have to do the BLT tomorrow. It's a bit to dark and cold now.

 

[miguelmcv]

The throttle body gets the leak in the FlAV (internally), it won’t show on a boost leak, basically it leaks from the intake pipe to the intake manifold.

Here is a thread in regards.
https://www.dsmtuners.com/threads/bad-fiav-what-do-i-do.366394/

 

[Sam's GSX]

Oh dang, I just looked into that thread, and that definitely sounds like my problem, because I have the biss screw all the way down, the tb completely closed and I have way to much air and its revving up on it's own because of that, so that makes sense, thanks so much man, I'll check that tomorrow

 

[Vegas Smith]

Your tps is still not set correctly. When the isc is hitting zero, that means the ecu is trying to lower your idle by lowering the amount of air entering the engine. You likely have a big vacuum as already stated. FIAV leak is a very good place to start as well as a brake boost.

 

[92AWDHX40]

The fiav.. is overlooked quite a bit.

 

[Sam's GSX]

Your tps is still not set correctly. When the isc is hitting zero, that means the ecu is trying to lower your idle by lowering the amount of air entering the engine. You likely have a big vacuum as already stated. FIAV leak is a very good place to start as well as a brake boost.

Yeah I have the throttle backed off right now, I did have it correct before though, I'm going to crack the fiav open tomorrow, I'd prefer to keep it if it's not broken, because it gets real cold here in the winters, but if I have to block it, that's fine too

 

[Sam's GSX]

*if it just needs a gasket

 

[Sam's GSX]

Ok quick update, I removed the throttle body, I wanted to remove the bottom portion but the head of 4 out of 5 screws stripped, not a big deal, if I need to remove them I'll find a way, i did remove the freeze plug, I had to turn the fiav 18 half turns in (9 turns) I hope that was the problem.
now, I do have a question, I'd prefer to keep the fiav valve functional, they say its supposed to be a trial and error thing to adjust it, but does that mean putting everything back together? And taking it apart again till its correct?
I'd prefer not to do that, so does someone have a general number of turns out that worked for them?
Thank you

 

[1990TSIAWDTALON]

Zero worked best for all of mine. I live where we have cold and hot weather and my cars don't care about the FIAV to be honest. It also takes the guess work out of if you have a leak there if sealed up correctly.

 

[Sam's GSX]

Ok, sounds good.
I believe and hope it was the fact it was backed out 9 turns, but if it wasn't, and say it was the gasket or something, would closing it fix the leak?

 

[Sam's GSX]

Also do I still need the water lines going to it if its closed?

 

[Sam's GSX]

(Just read an in depth post about it and I don't need the coolant lines) thank you guys, I'll post back if it fixed the problem

 

[1990TSIAWDTALON]

I was going to chime back in and tell you the lines are not needed. They HEAT the throttle body. I have mine capped off. Hope it works out good for you too!

 

[miguelmcv]

I even cut the water tubes from the throttle body for cleaner look and to open the space when working around it and never had a problem when cold.