iceblue

I have done allot of grounding work now and the car seems to run great. However it is giving a few quirks I would like some opinions on what causes it or what it may be. First off here is what I think is causing it.

1. Over ported TB
2. FPR
3. Injectors
4. ECU

Cruising down the highway 45mph 55mph 65mph running great it will suddenly drop off for 1 second and then come back like nothing happened and repeat this the exact same way. This only happens on cruise driving like you had cruise control. Some examples are feels like the car stops getting fuel for 1 second. The RPMs do not move but the exhaust tone drops off the car just drops off then suddenly comes back. I was trying to replicate the feeling and it acts like this for another description. Cruise and let off the gas pedal and get back on the pedal in the exact same spot like nothing happened. RPMs do not seem to affect this symptom.

Next one if driving very leisurely conserving gas around at and near the time the secondary’s come on line the car starts stuttering and surging bad jerking you back and forth. If you lay into the throttle more it stop or if you accelerated harder through this point it does not do it.

Next some times just every now and then you lay into it hard and it starts sputtering back maybe back fire. It can rev up keep doing it and it feels like it is not giving much power. But if you shift at any point during this sputtering the next gear pulls perfect. This is also not gear dependant it just does it when it wants too.

Icemark

S4?? S5??? Mods???

Sounds like TPS is mis-adjusted or bad and that the fuel filter or fuel tank filter is clogged

iceblue

Evrything is in my blog.
It is a S4 87 13bT motor in a S4 88GTU. Jusr replaced fule filter 2 days ago. New FD fuel pump with new sock 6 months ago.

The TPS is perfect at rest .97 to 1.4ohms and wide open at 4.75 ohms. I checked and checked for flat spots I could not get the meter to skip.

Mods.....
Ported knived and polished TB.
FMIC
JDM DP to 2.5in exhaust with 2in cat back.
I ran new electrical to the whol car and grounding kit as documented in the blog.
No emissions no AWS no ICS No spider rack new fuel lines.
RB oil baffle
N338 ECU
TII harness striped and converted to LHD
AFM inline with IC, Idle is stoich
New plugs but 2NGK wires on T and 2 Knowlogy hot wires on L untill I get a new set of 4 NGKs.

Icemark

blogs

what pressure sensor are you using??? A N327 or N315

Ekkk get those nology wires out of there... you have not seen the dyno test show on average a 5 HP on cars using them???

iceblue

I am geting new wires.
I dont know the number on the PS since I painted it. But I pulled it off my TII clip.

I forgot to allso add the the car loaps a little bit on idle. If you rev and hold it up to 2k it stops. If you turn the AC compressor on the idle smooths out like a babys butt. Turn the AC compressor off and it starts hunting again.

Icemark

sure sounds like TPS or spark. You may wish to check the TPS with a tester in the diagnostic plug or at the ECU.

I am assuming you also checked the basics like the fuel pump and for vac leaks?? I am also assuming that you used the N318 AFM from the Turbo???

Mint87RX7

if your going to check the tps with anything, use an O scope. you can clearly see blips that you wouldnt see with a digital or analog meter

iceblue

I would bet my left nutt there is no vac leaks I just had the whol uper hald off the car again. This is the second TPS but I have not tested it at the ECU. It still does it if I unplug it. Yes I do have the N318. Yea Pump is new and sure seems to be fine and there is 12V at the harness.