FLLS240

Hello everyone, my build is a 1992 Nissan 240sx with a 2004 Pontiac GTO ls1 and t56 transmission. It is a full track build that I personally built from the ground up in my garage. All oem wiring has been removed and I built a custom chassis harness and I am using a Wiring Specialties harness for the engine and trans. All stock internals, long tube headers, hp tuners flash to delete the security functions, rear o2s and emissions. Aeromotive fuel cell/340 pump with all -8an lines and fittings. At one point the engine was running very well, idling perfect and I was able to drive it up and down the street with no problems.


-My Problem-


After having the engine running for awhile I noticed that my battery was not receiving a charge from the alternator (reading around 11 or lower Volts at the battery and on the main terminal on the alt). So after replacing the battery with a new optima and doing some testing I replaced the Alt. After replacing the alt the engine would no longer hold an idle and seems to run rich. Also After replacing the alt it was still reading lower than 11 volts. So I did more research and come to find out that on the two pin connector going to my alt I only had one wiring receiving voltage which was the wiring that needs 12 volts. The wiring coming from the "indicator light" was dead. So I now have about 9 volts going to the second pin on the connecter via a resistor. The alt is now charging however the engine still does not hold an idle and runs very rich.

When I use my bosch scanner to pull codes it will pull a "indicator light malfunction" code. Any time the code shows up on the scanner the engine will try to die but if I delete the code the engine will idle fine for about 5 to 10 seconds and then the engine will just shut off and the code will reappear. This is all shown in this video -

I had a friend spray starter fluid on all the vacuum lines while I was keeping the engine from dying by giving it a little gas so that we could see if there were any vacuum leaks. After doing this for about 5 minutes the engine started to slowly idle better and on its own. Although it did not sound perfect and the idle would fluctuate when I would rev the engine, it was holding an idle. However after I shut the engine off it went right back to the way it was before. This video shows the data log while it was running for that short period. -

Fuel pressure is at about 60psi when running and drops to about 45-50 when not running.


Using a snap on scanner I pulled the following codes
- p0522 Engine Oil pressure sensor circuit signal low (sensor is not hooked up at all but it never has been even when running perfect)
- p0645 A/C compressor clutch relay control circuit (no a/c at all)
- p0650 MIL control circuit problem
- p0654 Engine speed output circuit problem
- p0101 Mass air flow circuit out of range


Any and all advise would be greatly appreciated.

340zxttaz

http://www.corvetteforum.com/forums/...e-problem.html

Youngblood16

I would bet its more based off the po654 code... if its setting an engine speed sensor code that could mean the sensor isn't sending signals to the ecm. If the ecm isnt getting signals it cant fire the plugs/injectors and your engine won't run.

sum guy

iTrader: (4)

Since its running rich I would be looking hard at that maf and circuit. If that checks ok and your afr is still off you can tune your maf curve with you hp tuner

240dan

Did you get anywhere on this problem? One thing I noticed while watching the video is how slow and labored the car cranks. This pulls the voltage down heavily and can cause reference voltage problems in multiple systems. (some of those codes MAY be a result) Since your engine is stock, a stock starter should have no problem spinning/starting it. Check the starter itself, connections and GROUNDS.

Also, since the engine is stock and your tune is simply a VATS/emissions delete you should not have to adjust any fueling at this point. Again, good connections, good grounds, a fully charged battery, and strong charging system are a must or you'll just be chasing your tail.

Really nice looking car BTW!

GreyFox

Nice car!