RB20DET in 1990 240sx wont start: Need info on 3 questions, please?

[s13_240_rb20]

Ok...to start things off, my baby has been lying dormant for 11 months now and I am finally ready to get her running again. I occasionally tried to start it and I succeeded to crank it about 3 times in the last 11 months. During one of those times, it bogged out at 10 mph or so...(yes I tried resetting the ECU). Before I get swamped with questions and before I get flamed for everything I do, did, didn't do, or ask.............please answer my three questions and I will love you forever

1: What OBD level is the 1990 240sx hatch 5sp?

2: What OBD level is the 1993 Skyline GTS-T 5sp (from which my RB20DET came)?

3: Which of those two should I be referring to (and where is the OBD connector) if I want to get the consult cable/software for diagnosing?

OK...with my three most important questions asked, I will try to tell a little about the car's history.

a. Engine swapped into the 1990 240sx in NOV '06.

b. Within 1 month, there was noticable power loss at the upper rpms. (Turning the enging off and restarting it would regain the upper-rpm-power for a matter of minutes.)

c. During the next 3-4 months, the rpm-point at which power was lost continued to drop. (Restarting the engine would still regain power for a matter of minutes).

d. Finally, around Feb '07, it began having difficulty to even start. If it started, it would barely rev without power loss (engine bogging out/choking).

And that's my story. Pretty much been parked ever since. Built a Prelude with a JDM H22 for a daily driver, so needless to say "I MISS MY NISSAN!!" Please only respond if you have helpful info...I already know that there is alottttt I don't know and I DO know that I don't need someone else to remind me that I don't know it...lol

Thanks, and thank you for having me as your newest member at nicoclub!!

--TJ

more pics at http://www.angelfire.com/ar/SP....html

[nismopwr240]

were there any modifications done to the car? this may help in pin pointing a problem.

[s13_240_rb20]

were there any modifications done to the car? this may help in pin pointing a problem.

No major mods...Only a nismo fpr and a Bosch Fuel pump...FP gauge shows ok.

--TJ

[craz4240]

Well to start the consult has to be wired in for the port to be active.

But if codes your looking for the fsm shows you how to read the flash codes off the ecu.

[s13_240_rb20]

Well to start the consult has to be wired in for the port to be active.

But if codes your looking for the fsm shows you how to read the flash codes off the ecu.

Can you please be a little more specific? you are talking to someone who has never done this before, so please don't spare the details.

I have traced my Yellow and Yellow/Green wires from my ecu pins 21 and 22 (which are the RX and TX signals) and they run to a white plug about 11 inches away. However this plug doesn't look like a 14-pin plug. I also found a seemingly unrelated plug wrapped up in the ecu wiring protection.

It is brown (which is the right color from what I have heard) but it has more than 14 pins on it AND my RX and TX wires did NOT go to it...

I am getting more confused. Can someone post a pic of their consult port from a RB20DET (or any car for that matter)?????

--TJ
Modified by s13_240_rb20 at 2:24 PM 1/29/2008

[mello88]

hi, welcome to the site.

One suggestion would be to replace your coolant temp sensor. Also how are your coil packs, does the engine sound like it's breaking up after a certain rpm? Sometimes the packs leak spark when they get hot/under load.. GL and update the thread when you figure it out.

Edit: Also do a boost leak check to make sure you don't have any boost/vac leaks, quick and easy assurance.

Edit2: Off topic, but, wow.. That wing and those wheels need to go LOL

[s13_240_rb20]

hi, welcome to the site.

Edit2: Off topic, but, wow.. That wing and those wheels need to go LOL

lol..the car came exactly as you saw it (except for the motor swap and the silver hood) for 500. Only drove it for a few months and then it crapped out on my. I'd love to do some boost checks, etc, etc, but I don't have a boost gauge installed and the car will turn over but just won't start up.

I am assuming that the Consult software will help me to identify any bad sensors/signals so I can get closer to the problem. I've tried testing temp sensors before but didn't get anywhere...

The only gauge that tells me anything significant is my FP gauge, and it shows a drop in FP after I stop turning the engine (probably significant) but I assume that the car would still start up.

But back to the consult problem. I've had some guidance passed down to me to trace the TX and RX wires (pins 21 and 22) to the consult port. However my consult port is shaped like "Q" in the following PDF file:

http://www.vkoslak.net/~rjames...s.pdf

Since it is not a "typical" shape for a consult port, I am guessing that I will need to get the USB cable AND splice in a matching female port to the appropriate signals. I feel more educated now, and I HOOOOPPPEEE that this is what I need to be doing to make the consult software work, and that the datascan software will help me figure out what's wrong with it....

any ideas??

--TJ

[craz4240]

Wow well that shows you where the tx and rx wires are but not where you hook them up...there is a writeup around somewheres I will see if I can find it.