Diagnose: Rough Idle/Rev; Miss Under Boost

[Justin]

Mods:

RonR short runner
Driftmotion IC
2.5 pipes all around
stock ct26
Aeromotive FPR
rc 550's
walbro fp
12v mod
maft pro with speed d. and boost control
tial bov
IS300 coil packs
Re-located batter (trunk)

I think that's all the mods that are relevant...

Codes:

24 (Normal, with the maft pro, I've read)
52 (must have messed up my knock sensors )
12 ( root of problem? read as to when it pops up.)




The problem:

My car sounds like a Subaru. At least that's the closest thing I can think of to describe it. It idles, drives, revs, everything it should do, it just does everything rough. Almost like a miss, but all injectors are firing, and I have not touched anything spark related that should effect my coils.

I just finished replacing my spark plugs, grounding my igniter better, and re-doing the ground on my battery.

I don't believe the problem is related to a Maft Pro setting, as when I unplug the Maft box and plug the AFM back in the problem still exists.

My plugs were VERY black, when I changed them 20 minutes ago.

When I tried boosting yesterday my afr stayed around the high 10, low 11 range, however the car was missing horribly. sounded like a shot gun going off repeatedly. I didn't try it again

When that occurred a Code 12 popped up. Only time a code 12 will show.

It is worth noting that before I installed the ffim, ic, pipes, injectors, maft, etc. the car ran wonderfully.


Any suggestions as where to start?

Thanks everyone

 

[shaeff]

CODE 12
RPM Signal
Diagnosis
* No "NE" or "G" signal to ECU within 2 seconds after engine has been cranked.
Trouble Area
* Distributor, or CPS, circuit
* Distributor or CPS
* Starter signal circuit
* ECU

Check to make sure that none of the wires around the CPS are corroded, charred, hardened by heat, and generally not conductive. I'm willing to guess that the connector has seen better days. Heat doesn't do it any favors.

CODE 52
Knock Sensor Signal
Diagnosis
* Open or short circuit in knock sensor signal.
Trouble Area
* Knock sensor circuit
* Knock sensor
* ECU

Fix that, either by re-wiring, or just fixing what you did wrong. With code 52, the ECU will retard the timing, add fuel, and the car will run like crap. It will cough and sputter under boost, run very rich, and have an overall lack of power.

Once you get the codes cleared up, I'm willing to bet the car will run quite differently, even if you still have some problems. But, by removing all those codes, we will be able to pinpoint the problem much more quickly.

 

[TheNewRed]

Sounds similar to my 52, but no missing under boost. Mine runs pretty normal, but i cant tell if it has a lack of power due to slipping of the stock clutch. Order Shaeff's rewire kit, im praying that, and jetjock's advice will cure my 52:biglaugh:!!!

 

[Justin]

Check to make sure that none of the wires around the CPS are corroded, charred, hardened by heat, and generally not conductive. I'm willing to guess that the connector has seen better days. Heat doesn't do it any favors.

I should have mentioned that. I've gone over the connector rather thoroughly. Granted the wires are not in the best shape, but they're defiantly okay, visually. Keep in mine, the code 12 only shows up under boost.

Fix that, either by re-wiring, or just fixing what you did wrong. With code 52, the ECU will retard the timing, add fuel, and the car will run like crap. It will cough and sputter under boost, run very rich, and have an overall lack of power.

Once you get the codes cleared up, I'm willing to bet the car will run quite differently, even if you still have some problems. But, by removing all those codes, we will be able to pinpoint the problem much more quickly.

Yeah I guess that's the right way to go. I hope I didn't jack up my knock sensors. My harness is only about 4k miles old. I bought it brand new