1200-1500rpm idle bump
 

After looking over everything countless number of times i was finally able to get the 6port turbo to idle!

My first mistake was the 2 prong yellow connector for the fuel pump, i had plugged into the back of the alternator, i mean it fit perfectly and it was the only connector of its kind. Anyways i unplugged it, and i also found out that i did not have my vacuum line from the break booster connected to the intake.

The engine is completely stock, egr delete, emissions/smog delete, omp delete only premix.

So after messing around with the throttle cable and guessing on where to set the idle screw, i adjusted the tps to 1000ohms. I gave it slight amount of gas with the pedal when trying to start it and after a few cranks it started up, i let it warm up with having my foot slightly on the accelerator pedal just in case. After it warmed up it idled at 1200 and bumped to about 1500 or so rpms. I was able to rev the engine to a high rpm without spuddering or stalling or backfiring or whatever, when i got to 8000rpm it shot flames out the exhaust haha. Im pretty sure there are no vacuum leaks as of now. Is it possible that if i have the idle speed adjusted to high or low and set the tps to 1k ohms, that could be the issue with the idle bump? What should i do as of now?

btw there is no coolant in the engine, just water for now. the buzzer is still going off?
Also i would like to mention, after running it, i came back out an hour later and tried starting it without giving it any gas and it started immediately and idled at 1200-1500rpm
Sorry for the bad quality but hopefully this helps :)

Mine is doing the same thing. I'm going to bleed the air from my radiator to see if air is stuck in the thermowax valve causing the jumping idle. Also the fast idle cam could be jammed open which could also be what's wrong with mine

1badvert

I did the thermowax delete and secondary butterfly delete. The high idle is adjustable isnt it?

Did you delete the fast idle cam also?

1badvert

i dont think so, heres a video of today i tried a stock s4 n/a throttle body which had all the crap on it still. still bumps idle, also i couldn't get it to start after i had it running, i think i flooded it lol.

oh the engine is quite shaky when its idling

Does it idle normal when not in neutral? Did u check for vacuum leaks?

1badvert

the car doesnt move, it was in neutral. Need a new slave cylinder hahah

mass air flow sensor? maybe?

the more i research this, i see a lot of similar idle issues and they all had a bad tps or miss adjusted tps. My car was obviously idling way to high in the video, I think my next step is to, adjust the idle lower and re adjust the tps, then check for vacuum leaks and try again :p. If i still have the issue im going to test my maf sensor. Im still puzzled as to why its kinda hard to start sometimes? Tomorrow i can hopefully make a video of it starting.

With all the stuff you've removed, it seems that the engine is far from stock. Anyway, when you adjust the TPS, do you ground the initial set connector first? I'm assuming your car is an S5. Without doing this, any TPS adjustments are basically worthless.

And the idle needs to be lower when adjusting the TPS.

Its an s4, i figured i need to bring the idle down a little more and try again

I tried messing around with the tps some more and i tried adjusting the throttle body and now it starts up and dies again like it used too. Im not to sure how to adjust the throttle body correctly since its been modded. Even the stock throttle body looks like a nightmare to adjust. I tried unplugging my maf and the idle bump disapeered but the engine was slightly shaky, so im assuming that my idle bump is because of my maf. Im just having a hard time to get it to idle at 1000 to 900, the engine runs great other than the idle. It revs very smoothly to every rpm past 1700 or so. I need some starting points for my throttle body. I have no thermowax or secondary butterfly. I could use my n/a throttle body if i have to and run coolant to the tb.

So, for an S4 you will be shorting the initial set connector first. (S5's have to ground the connector) Then start the engine (it should already be fully warmed up). Adjust the idle to as close to 750 as you can get it then adjust the TPS to 1000 OHMS or 1 volt or one test light lit (whichever method you use). Turn the engine off and remove the initial set connector short. Crank the engine and take it out for a short drive to see how the idle performs. Come back and repeat the process to fine tune the idle speed and the TPS setting. If this doesn't solve the problem, then you can rule out the TPS and move on to other stuff.

The problem is when i messed with the tps and throttle body i cant even get the engine to start now, it will start and die immediately. When i messed with it before i got it to run and idle, but it had that aggressive idle bump.

Anyone have a clue whats going on here??? Now that i messed with the tps and throttle body some more, it just starts up and dies right away... i have tried adjusting the tps back to 1000ohms or 1v and it still just starts up and dies. Maybe this is partially related to my MAF?

The engine should not need a TPS to start. So, it seems that any or some of the throttle adjustments is your problem. When it comes to tinkering w/the previous settings it is always good to remember how things were previously just in case you need to revert back to how it was originally.

ok, heres a video of me testing the afm

Come on peeps i got videos and everything! Anyone?

I'm not sure about mass airflow sensors but usually its a way for O'rliey to charge you a buttload in parts that wont fix the problem.

I am dealing with this same problem. Luckily, my car still starts because I haven't fooled with it too much. I just did a Resistance of the Throttle Position Sensor with someone.

Did you measure the resistance directly off of the sensor and adjust the screw? At closed throttle, the right two pins is how to measure it on Ohm setting. Should have resistance of 0.8-1.2 kohms Full throttle should be 4.0-6.0 kohms. Full range is the top left pin and the bottom middle pin. Resistance should be 0.6kohms to 0.9 kohms closed. at full throttle for full range 3.4-5.1 kohms.

I do not have a turbo but I have a S5 with a 6pi and VDI system. Also, Try the timing gun and ground the 1 pin green connector on the drivers side by the battery. I didn't delete any components but My idle is high and hunting like yours.

I ripped my main engine to manifold gasket this is why I suspect the hunting (Idle variance of 500 or more). It indicates a vacuum leak. I just did my vacuum lines with new silicone and also got the 6pi and VDI moving freely but still idling high.

If anyone does have good info on how to lower idle Please enter it. In California, a car has to idle at 750rpm or it fails emission test.

Does your Rx7 Do anything like this?

The TPS will have a major effect on idle and just above idle. If you have a dead spot or the TPS is slightly out of adjustment, the contacts dirty, you will have this issue

It isn't wise to delete the components. At all from what I hear. I just passed California emissions test.

I did all of my vacuum lines from Boostcontroller.com.
I found out a few components that were shot. The PCV (Purge control valve on oil filler cap), the intake thermosensor (engine), I mistakenly replaced the throttle body but the one I had was way out of adjustment, and I replaced the engine to lower intake manifold gasket (metal).

I took the car to my local rotary mechanic and we found out the Throttle Position Sensor (TPS) was bad. With this bad TPS, I noticed the acceleration was severely laggy and the car died a lot while trying to warm up in the morning.

On the first visit, he bled the bubbles out of the radiator, adjusted the timing, adjusted the sensor (flathead screw) on top of the intake manifold by the throttlebody, and messed with the tps.

On the second visit I replaced the tps with a good one, he adjusted it, messed with the screw on top of the intake manifold, and did the timing once more.

When I first came in the car was hunting and the idle was high 1,300-1,800rpm. He kept talking about a "Fast Idle Screw."

I hope that helps and your S5 runs better.