Nistune Forums

Hi everyone,

I'm having some problems getting my car to a running state to drive it to the tuner. I'll start from the start.

Car in question is an S13 180SX running an RB30ET (SOHC) running off an R32 RB20DET ECU. Mods:

RB30ET
T04E, 10PSI
450cc Bosch 968 injectors (http://www.fiveomotorsport.com/bosch-gr ... 0280155968)
CPC street plenum, 90mm LS TB using RB20 TPS
R35 GTR AFM, 70mm OD pipe
RB25 CTS & ignitor
AU coil packs
RB30 AAC valve
Knock Sensors deleted
Everything else is as per RB20.

Basic tune run down to get to dyno:

Resized for AFM (R35 GTR VQ map for 75mm pipe so presume a little off, needs to be looked at on dyno), tick all boxes
Resized injectors stock > 450cc, tick all boxes
Adjust latency stock > 0.459ms (site recommends values for 12V and 14V, which should I be using?)
Base timing on CAS set to around 15>20deg BTDC as per normal RB30.

Car fired up OK, needed aerostart to initially start (might need more crank enrichment? Water temp was 30degC "cold" (pretty hot day in the sun). Revved and idled cleanly for ~ 5 mins on the spot. No black smoke out the exhaust (I don't have a wideband unfortunately).

Went to take the car out for a test drive, idle began fluctuating. Then when driving the power would drop in and out, maybe 2 seconds each way (went from normal to completely cutting out) made it half way around the block, first slight incline and the car cut out, and wouldn't refire. Temp had barely changed. Towed the car home and let it completely cool down. Rechecked the timing, eventually got the car to start, wouldn't idle, would rev quite cleanly though > ~2000rpm. I recorded some logs, please find them attached.

Noticable things on the logs:
- Battery voltage doesn't go up when the car starts, stays around 12V. Will get another alternator.
- o2 sensor displays same reading throughout the log, will replace, could this cause the issue?
- FP Error code?

Is there anything else obviously wrong with the tune? The car seems to backfire through the inlet and exhaust when at low RPM, could this be a timing issue?

Any help would be much appreciated!

James

Post the tune here

Only tick TP box in MAF resize. Also check tp scalers afterwards (compare to factory)

O2 sensor may be dead? 0.31V stuck

Tune is below, I also lowered the K a bit, seemed to make it run better and stopped blowing black smoke.

Ah ok, I'll redo the tune with the other boxes unticked, I've yet to change the fuel and timing maps to be relative to an RB30ET stock tune. As we discussed the other day, the pipe is 70mm, so I'm guessing the VQ map will be out, but I'm hoping not by much. At least the voltage rises and falls with rpm correctly now (was wired wrong )

No code for O2 but yeah I noticed that, I'll go buy one this arvo. The alternator was off an R32 GTR but I'm sure it will be generic enough that I should be able to buy a new one without too much trouble. Probably wont be able to order one for a few days though.

Is the AAC valve reading high? I have a standard RB30 one in place, but the large hex thing with the plug on the end has been blanked just using a cut down bolt the right size. The RB20 loom doesn't have a plug for it anyway, hope that doesn't affect things.

Oh something I forgot in the first post, the car doesn't run an air regulator either.

Cheers for the help mate

O2 sensor was dud, winning! (For once not a wiring cock up)

I had only ticked the TP box for the tune, I left the half and double values boxes unticked (as we discussed). The right hand TP column on the Ign and Fuel maps is one value less than a stock R32 map. I looked at the RB20DET vs RB30ET for fuel, the numbers are similar in the lower half but up top the 30ET maps are around twice that of the 20DET. I'm getting a wideband on the weekend so I'll have a better look then.

Car isn't really that different, runs cleaner but did its power cut in and out think again which cleans up when you rev higher. Still won't idle or run properly at low revs, is it a AAC or AFM (VQ map?) problem?

Sorry for the delay... Just some notes

- Yes you may need to adjust your crank enrich tables if still problems with cranking
- Make sure knock sensors are using 470k when deleting
- Check the R31/R32 temp sensors are compatible. Can you use the R32 sensor? If temp is stuck around 50 degC
- Alternator should be reading about 14V. Check with a multimeter
- O2 sensor needs replacing as you found
- Fuel pump error code can be ignored. If you are using aftermarket fuel pump or via relay
- What are your AFRs like at idle?
- AAC is used to maintain idle closed loop around 800rpm (based on target rpm table). Wont be a problem with this the tune is too lean/rich. May need to adjust K constant until AFRs are 14.7:1 around idle then richer going on boost