ATTN: Hooper, JRCivic, rjaffey, and other SC Gurus

[MouhadIb]

My car was taken to the dealership to have it looked at since the CEL had been on since I got the car back from the SC install. The car had been throwing a code 14 since the install and the idle was REALLY bad. The car is a 1998 GSR and this is what my friend Hassan told me when he took it to the dealership....
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>
From Hassan,

Okay here is what Norm (Acura Tech) told me.... He connected the PGM reader to the car and got the two codes.... The one for the IAT sensor was due to low voltage, I think we fixed it since me and norm found out that the wire was disconnected and you (MouhadIb) and I connected it. The IACV is only getting 5v and the reader said that there was a faulty circuit.
That is pretty much it except the fact that one of the mechanics said that all the JR S/C cars he has seen have the same codes.<HR></BLOCKQUOTE>

Can anyone help me in figuring out wether the ECU is bad or if there is a short somewhere? If the ECU is bad should I get an OBD I puter??

Thanks and all your responses are appreciated.


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It take a Nation of Millions to hold Us Back!!!


C-SpeedRacing

[This message has been edited by MouhadIb (edited November 19, 2000).]

[This message has been edited by MouhadIb (edited November 19, 2000).]

[Mr Rogers]

Man, I have no idea what could be going on with the IACV but if they are see this repeatedly, why don't they know what is wrong? On the computer, I don't know if the OBDI guys have too much of an advantage over us once the SC is a factor. Besides, ultimately we all are in need of changing what the ecu sees anyway to take care of off boost & boost situations with some sort of voltage trickery. Just my 2c so good luck and let us know what happens.

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98 GS-scR w/ 8psi JRSC, Walbro HO fuel pump, AEM cai, DC 4-2-1 one peice header, Thermal Exhaust, Skunk Works cam gears, J&S safeguard, RC 310's, Cartech FMU, Vortech regulator, H&R sports and KYB AGX's, and of course to slow down, KVR X-drill F&R rotors and Carbon Kevlar pads and V1 to signal the slowing down and soon to go on the "Juice" and a CF diet.
Best et ==&gt;13.6 @ 103mph w/ 2.3 60ft

[Holden]

I had a Code 14 and it was caused by a vacuum leak on one of the vacuum fittings on top of the S-neck where the throttle body attaches.

A couple of hose clamps and I've never seen another code since.

Greg

[hooper]

I told you it was strange. I spent 8 hours diagnosing that thing. I went thru evrey trouble-shoot in your manual trying to find it. I can't remember what the number it was, but according to the helm's, the code it was throwing, at the time, was for the O2 sensor. The problem was that after installation, the wiring harness connecting to the O2 sensor was too short to reach the sensor itself. And I think it pulled a wire loose somewhere, before I could redo that portion. But, according to the run down in the helm's, everything checked out. I was just as frustrated as you are. I tried undoing everything, to backtrack the problem, and still had no luck.
Did you ever replace the IACV and the O2 sensor? I might try swapping the computer (from a friends car, or something)temporarily to see if it changes.
Whenever I have had trouble with a code I couldn't track down on my car(OBD-I), it would end up being something OTHER than what the code said. What I would find out from the manual is that several sensors have a wire in common that feeds to the ECU for the CEL. One occasion the CEL indicated th O2 sensor. After hours of diagnosing, and $100+ for a new sensor, it ended up being a cracked IAT sensor. On the early civic kits, all that was done there was a resistor in line. Well the IAT sensor went bad, but since the resistance on that wire was now changed, the ECU interpreted it as the O2. I looked at the wiring diagram, and there is on wire that loops from the O2, IAT, MAP, and a couple other sensors. The ECU just wasn't getting an accurate reading. I'd be willing to bet it is something like that, and when you find it, we're both going to go...
DOH!!

[MouhadIb]

Well it's not a vaccum line problem. The problem lies in that the sensor plug for the IACV is ONLY getting 5 volts and NOT 12V. This is another factor. We do not know if it's supposed to get 5v or 12v.

Phil,
Can you tell me which part you tugged on to see if there is a wire disconnected from there?

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It take a Nation of Millions to hold Us Back!!!


C-SpeedRacing

[This message has been edited by MouhadIb (edited November 20, 2000).]

[BlownAway]

I had to lengthen the wire harness to my IACV on installing my S/C (O2 sensor too). Seems that these harnesses can be wrapped differently - some fit back into their sockets with the S/C installed, some don't. I'd check the wiring, between the shock tower main plug and the IACV plug. These are color coded so you many not need the wiring diagram. Wiggle the IACV plug a little when checking each wire for continuity.

[hooper]

Jay,
What happened was this: the wiring harness that connects to the O2 sensor plug reached, tight. But it reached. But when the car was started, I noticed that there would not be enough slack when the engine was revved and the engine moved. So, that's when I went back and fixed it. I'm just afraid I got it to late.
Anyway, to see it best, it has to be looked at from the bottom of the car. You'll see that the short harness from the O2 sensor connects to the main harness just under the oil seperator, and there is little slack in the it. The problem is that if there is a broken/shorted wire, you can't get to it without removing the entire blower and unwrapping the main harness.
The good news is that I checked the voltage/resistence per the helm's instructions, and everything checked out as if there were no problems. Yet there IS.

[JRCivic]

I do not believe that ANY of the sensors listed above, which incidentally all have a voltage source in common, should be getting anything more than 5v+.

Check all sensor output readings to make sure you stay in range... if not, there is your problem. It is common for the IAT to short out, especially if you have done major surgery on the blower/manifold area.

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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.68 at 110 mph

[MouhadIb]

The thing that I am concerned about is that when we checked the voltage on a G2, the IACV sensor Voltage was 12v. This is why we don't know if the sensor on my car is not getting the proper voltage?

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It take a Nation of Millions to hold Us Back!!!


C-SpeedRacing

[This message has been edited by MouhadIb (edited November 21, 2000).]

[mr detail]

I might be coming into this way too late but could it be you have the wrong harnesses plugged in. It would not be the first time or the last. Could the TPS and the IAC be plugged in to the wrong sensor?