S14 w/ S13 SR20det// rich at idle/lean on boost

[Luvs2slide]

Figured I would reach out to the oldschool (and maybe newschool) guys on Zilvia about my current issue.


Car is a 95 S14 original auto but converted to 5 speed. Built s13 SR20det (forged internals/stock new head components). Car currently running on a RS Enthalpy tuned ECU. At idle, I'm getting AFR of about 11.0 and during boost AFR is about 15.0 (this is 4th gear pulls).


Mods are pretty basic:


WS converted specific harness
RS Enthalpy tune (verified by Martin and working condition)
550 cc sti injectors (cleaned/flowtested/no leaks by Deatschwerks)
R32 GTR fuel pump
S15 turbo/boost on oem wastegate approx. 7-8 psi
JWT 260 cams
Z32 MAF
AFRs verified on new Innovate SCG-1


This is what I've tried so far:


-Two used oem FPRs both read approx. 46 psi w/ no vac & 40 w/ vac
- Sard FPR (set to 43.5 psi no vac) although I havn't adjusted it lower yet
- New Coolant temp sensor (CTS)
- New oem IACV
- mechanical Timing checked good with chain in proper position. But CAS is maxed out to achieve 15 degrees (think this still may be an issue but car runs and drives good for the most part except for the AFR stuff). Timing was checked both with the timing loop and with spark plug wire extension method along w/ disconnecting TPS
- Compression is great 150-160 psi
- TPS dialed in correctly
- Went through like 3 sets of new plugs already gapped to 0.28, most are black indicating rich condition
- CEL codes returns a 55 which means no issues
- Tried two used Z32 N62 MAFs no changes (although I'm using the ISR connector with extra ground wire. Tried grounding that wire and leaving unhooked notice about 0.5 AFR change. Although I been told to leave it disconnected to prevent ground loops.


So that's where I'm currently at. My next step is to somehow see what my fuel pressure is during boost. I have a new Walbro 255 pump coming in to see if the pump is just going bad). Other than that I'm out of ideas =/

[S14rebuild]

There should be no reason for the cas to be pinned all the way advanced or all the way retard to get proper timing...

[Luvs2slide]

I agree 100%. FWIW, the car still pulls strong. And I can reach 1 bar no problem with the boost controller. If the timing was off, or at least waaayy off, the engine wouldn’t even start

[mewantkouki]

You need to use a basic inductive timing light if you're going to use a spark plug wire to measure timing on and sr20.
Dial back lights might give you a false reading. They are designed to be used with the coilpack harness grounding loop.
I've measured signal from three different positions: grounding loop, #1 coil pack lead, and using a spark plug wire and gotten different timing readings each time with the car locked in timing mode.

[TheRealSy90]

Personally I wouldn't be out hitting 1 bar of boost with the AFR showing 15.0

[Luvs2slide]

Originally Posted by TheRealSy90

Personally I wouldn't be out hitting 1 bar of boost with the AFR showing 15.0

The first time I noticed it I disconnect the boost controller and currently running off the stock wastegate pressure. But even now I’m the current state of the car I’m not even going into boost until I can figure out what’s causing it

[Luvs2slide]

Originally Posted by mewantkouki

You need to use a basic inductive timing light if you're going to use a spark plug wire to measure timing on and sr20.
Dial back lights might give you a false reading. They are designed to be used with the coilpack harness grounding loop.
I've measured signal from three different positions: grounding loop, #1 coil pack lead, and using a spark plug wire and gotten different timing readings each time with the car locked in timing mode.

Wow that’s crazy it’s giving different readings like that. Unfortunately I don’t have the stock coilpacks and harness to go with the loop as it has splitfires. But the timing light I’m using is an older model military edition that (as far as I know) works pretty good. I check the timing again yesterday and it’s still at 15 degrees and I adjusted my iacv to get approx 750 idle. It dies at times coming to a stop but I attribute that to the condition and probably the cams

[err]

Was the car running fine, then all of a sudden it just started to run bad? I would recommend re-doing your timing. CAS is maxed out and your only at 15 degree is not right. Its also free to do if your handy with a wrench.

are those injector 04-05 sti yellow top side feed, and do you have the flow chart for them? 04-05 yellow top side feed sti injectors are around 500-515cc and not 550cc

[Luvs2slide]

Originally Posted by err

Was the car running fine, then all of a sudden it just started to run bad? I would recommend re-doing your timing. CAS is maxed out and your only at 15 degree is not right. Its also free to do if your handy with a wrench.

are those injector 04-05 sti yellow top side feed, and do you have the flow chart for them? 04-05 yellow top side feed sti injectors are around 500-515cc and not 550cc

The motor is new (built) so I guess this a new issue as I’ve been correcting things here and there.

I agree that the timing may still be off and need to find time to redo it.

Injectors were sent off and flow tested by Deatschwerks. Their report states all injectors were about 560cc and in their words “perfect.” So I guess I can rule those out.

[Luvs2slide]

Originally Posted by Jerometon

curious why you use the 6 rib set up vs LSA ? you did 90 of the work necessary to install it all

did you get boost districts new larger heat exchanger ?

What?