stall spot
 

I have developed a (hic-up) stall spot around 4000 to 4500 rpm.
It started kinda small but has gotten worse. If i go wot in 1st it will pass through the spot rather qiuckly with only a little jump. but down shift from 5 to 4th and go wot and it actually struggles to get by the miss.

I have replaced spark plugs, and wires . I look at the wideband and at the miss it looks to stay the same 10.5 under boost, It is at the beginning of boost (damn hybrid) about 2 psi. I looked the the load maps to see if any thing looked irregular. The car pulls great through the "spot" when not at wot.

Steve Kan tuned the car and it has ran flawless before this. I did have one problem with the CAS but it is fixed now.

any suggestions


Thanks in advance

Johny

10.5:1 at 2psi boost???

if that is the case it is a rich misfire...

Ignore the PM .

But it wasn't missing before and nothing has changed.
Oh and TPS adjusted .
Is the TPS suppose to read 99% from about halfway down?

Thanks

The TPS setting could affect the a/f ratio on part throttle dramatically. It shouldn't be lower than 11.5:1 a/f during the staging. however, it has to be 1 point richer before staging in order to get rid of the staging hesitation. so if it was around 13:1 before staging, the staging a/f has to be 12:1 to make it smooth w/o feeling the secondary engage.

Try to recalibrate the TPS first and see how it works out.

i have the same issue but between 3500 and 4000 could it be the secondary staging point?

The TPS IS calibrated.
Is it suppose to read 99% from about half way down?

Thanks

half way should be 50% and WOT should be 50%. If you're running the series 4 throttle body, that maybe the problem since the TPS looses its contact at 50% throttle.

So what do I need to do? another s4 tps or go to s5? sorry if I'm dense.

I actually have the same problem, if i switched to a s5 tb is there a way to wire the TPS from the s5 in seeing how it has a low and high (6 wires) ?

After seaching again the TPS is only used for on and off idle so it only reads full wot at half way down. I remember this from my SAFC but I had forgotten. I don't think this is the problem Ill keep you posted "Mr fuzzy"

on the S5 TB, there're two sensors for the TPS, one is the narrow range and the other is the full range. All you have to do is to rewire your TPS input to the full range TPS to get the full effect of the TPS. The problem I C on aftermarket EMS with the S4 TB is that it shows 50% when you barely touch the throttle. EMS just dumps the fuel thinking you're ready to go when you're just barely touching it. I had a hard time calibrating the a/f ratio on S4 engines because of this. Haltech comes with a TPS sensor that can be added to the TB but I don't recall microtech offering this option

i wish they did im gettin way bad MPG with base i got 17 now i upped the stage% for my 720s and am getting >13. Is there a spot on the s5 TB for the oil lever thats on the s4?

Mr Fuzzy I just made a s4 to s5 TPS Ill let you know how it goes.
The thing that bothers me is that the car has been running fine up to now.


Johny

maybe your tps just went bad, how did you make it to a s5?

actually it makes no difference what the TPS reads, it is only used for off idle transitions, as long as it reads 0% when closed that is all that matters,


if you are 11.5:1 at 2psi you are too rich and it is a rich misfire causing your problems, put some new plugs in it and i bet it goes away

I cleaned the plugs but they are a little cooler, I will try some 9's and 7's


Thanks
Johny