Codes 71, 72, 73 and 74

[Turismo]

Do you have stock injectors?

[jchcinmax]

I had codes 71 &72 when I put some CHEAP octane booster in my gas tank. I just re-fueled and put some good octane booster and problems went away. Could be contaminated fuel or clogged injectors.

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Romans 5:1,John 3:16
96 red GSR w/mods..like a JRSC.

[gsrev]

make sure your plug wires are nice and tight. Secondly, is it possible you put the wires in the wrong places. Double check to make sure you firing order for the wires are correct, if not you will definatley get those codes.

[Batoutahell]

I have stock typeR injectors. Maybe it's a bad tank of gas, but I think I'm experiencing a long-term problem that's been with me for a few weeks now. If I had to guess, I'd say that whatever tripped my map sensor code (which mysteriously went away) is manifesting itself in today's new engine codes. Although my map sensor CEL hasn't gone off for a week now, the car never did drive right.

I swallowed my pride and double-checked that my ignition wires were in the right holes. At least they're ok. I may brave the cold tonight and check inside the distributor for loose connections.

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'00ITR#739
JRSC, JR Walbro FP, JR intake, J&S SafeGuard, JR BTC, v-afc

[Batoutahell]

First off, thanks to everyone for their help and support with my CEL issues lately. For the past few weeks, I've been running very rich in limp mode (map sensor code). For weeks, I went over my map sensor wires with a fine tooth comb and couldn't find a problem. The other day, I changed spark plugs and ran injector cleaner through the car this morning. My old plugs were black w/ carbon and smelled like gasoline. Changing the plugs didn't seem to help much. My a/f meter bounces up and down, but it still does so violently, from totally rich to totally lean and back. I can feel the car cough and sputter as the a/f shows the unsteady fuel delivery. On occasion the car will stall from idle. Today, the CEL came on again, throwing new codes: 71, 72, 73 and 74, which are generic misfire codes. Any number of things could be wrong (ICM, ignition wires, fuel pump, fpr). Do these symptoms sound familiar to anyone to suggest a diagnosis? Any help is really appreciated.

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'00ITR#739
JRSC, JR Walbro FP, JR intake, J&S SafeGuard, JR BTC, v-afc

[lundgren]

If you map sensor is failing, or the signal from the v-afc to the map sensor isn't working, it can cause the car to run lean or rich, and cause the codes you've seen.

[Mr Rogers]

What kind of spark plugs did you put in? I had put some Bosch 4+'s in about a year ago and started getting the misfire codes. I pulled the plugs only to find that one had all but fallenin the cylinder. The metal center had completely come away from the porcelin center. JUNK! Check the plugs and make sure everything is all good there. Have you did a sensor check with the VAFC? I was reading my instructions (since I haven't put it in yet) and it says something about being able to check out your sensors. Good luck man

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98 GS-scR w/ 8psi JRSC, Walbro HO fuel pump, AEM cai, DC 4-2-1 one piece 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. *ITR LSD, JR flywheel, Clutch Specialties stage 4, MSD digital 6 & HVC coil, NX Gen-X kit and CF diet going on soon....
Best et ==>13.6 @ 103mph w/ 2.3 60ft on Nitto drag radials

[Batoutahell]

Ah Ha! PROBLEM SOLVED!! I started off today checking for proper resistance across the spark plug wires, then checking for loose connections inside the distributor. No luck. Then, I replaced my distributor rotor (it had a little carbon build-up). No better. Then, I checked my fuel pressure; I started at 60psi static, first raised and lowered it looking for signs of improvement. No luck. I was getting down to the bottom of my bag of tricks. I decided to try and take the v-afc out of the loop. I installed some quick-disconnects on the MAP signal wire just before the v-afc connector and re-established the continuity of the MAP wire before it went to the v-afc. Now, it runs directly from the MAP sensor to the ECU. The car runs PERFECT. Idles at 800rpm, a/f meter oscillates smoothly, engine doesn't "cough" and car isn't blowing black smoke out the tail. Now with the MAP sensor wire re-routed, the v-afc is nothing more than an expensive tachometer, but at least the car runs fine now. I'll call Apexi to see if they'll take a look at the unit for problems. At last my month-long headache is over. Now I can concentrate on making my car faster again.

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'00ITR#739
JRSC, JR Walbro FP, JR intake, J&S SafeGuard, JR BTC, v-afc