RB20DET start and limp mode issue - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Con-city_s13 · 03-09-2013, 07:42 PM

I have an '93 s13 with an all stock rb20det swapped in and I am having issues starting. The engine cranks and fires, but after firing a few cylinders it jumps up and down between 500rpm and nearly 0rpm. After about thirty seconds of this it dies. However, once out of like 30 attempts at starting, it cranks right up and runs smooth. It will idle anywhere from 1000rpm to 1600rpm, which is a little high.

Also, when I rev it it starts to cut out like it's in limp mode at 2500rpm. I've read that this is caused by a maf issue. I have a Wiring Specialties conversion harness so I do not think wiring is an issue. The engine will not even fire with the maf completely off.

So my questions are:
What is causing my inconsistant starting issue?
Is the maf limp mode the only cause for my rev issue?
Could my maf still be bad causing both of my problems?

I would really appreciate any help on the subject.

RB240Coupe · 03-27-2013, 08:15 AM

I would try looking for vacuum leaks.

dannyboy41089 · 04-05-2013, 10:48 PM

i agree start with simple things such as leaks. if youre running the stock rb20 maf (j60), it might be time to replace it. Had this issue a while back and replaced the maf. Another thing to check would be your tps. Make the sure you have the right voltage.

Cheers!

OrangeVirus1 · 04-05-2013, 11:14 PM

sounds like a dead maf. Also I'd check your Coil packs to make sure they aren't arching spark to the head, or are cracked up.

Also, My car did this too sometimes ( RB20 ) ended up being my Ignitor was dying.

Con-city_s13 · 04-18-2013, 08:18 PM

Well I actually did some research on my maf, engine and ecu. I found out I have a cefiro rb20det with r32 maf and computer. I am going to try and find a cefiro maf and reflash the r32 ecu to match all of the sensors on the engine.

Just to be thorough, I have checked vacuum lines, tps, and coils.

Con-city_s13 · 04-18-2013, 08:23 PM

I also no longer have the no start issue, but it's still in and out of limp mode.
Also, I have charging issues as well. The alternator will pass every bench test I can give it, but fails to charge the battery when on the car. Possibly can be solved with an ecu reflash to match the engine? This one is really stumping me because I dont want to replace it w/o knowing it's bad.

03-09-2013, 07:42 PM	#1
Con-city_s13 Join Date: Jan 2012 Location: Concord, NC Posts: 43 Trader Rating: (0) Feedback Score: 0 reviews	RB20DET start and limp mode issue I have an '93 s13 with an all stock rb20det swapped in and I am having issues starting. The engine cranks and fires, but after firing a few cylinders it jumps up and down between 500rpm and nearly 0rpm. After about thirty seconds of this it dies. However, once out of like 30 attempts at starting, it cranks right up and runs smooth. It will idle anywhere from 1000rpm to 1600rpm, which is a little high. Also, when I rev it it starts to cut out like it's in limp mode at 2500rpm. I've read that this is caused by a maf issue. I have a Wiring Specialties conversion harness so I do not think wiring is an issue. The engine will not even fire with the maf completely off. So my questions are: What is causing my inconsistant starting issue? Is the maf limp mode the only cause for my rev issue? Could my maf still be bad causing both of my problems? I would really appreciate any help on the subject.

03-27-2013, 08:15 AM	#2
RB240Coupe Leaky Injector Join Date: Jan 2012 Location: virginia Age: 35 Posts: 57 Trader Rating: (7) Feedback Score: 7 reviews	I would try looking for vacuum leaks.

04-05-2013, 10:48 PM	#3
dannyboy41089 Join Date: Jul 2012 Location: greenville sc Age: 35 Posts: 10 Trader Rating: (0) Feedback Score: 0 reviews	i agree start with simple things such as leaks. if youre running the stock rb20 maf (j60), it might be time to replace it. Had this issue a while back and replaced the maf. Another thing to check would be your tps. Make the sure you have the right voltage. Cheers!

04-05-2013, 11:14 PM	#4
OrangeVirus1 BANNED Join Date: Jan 2013 Location: PyongYang DPRK-N. Korea, Province 2 Posts: 1,236 Trader Rating: (0) Feedback Score: 0 reviews	sounds like a dead maf. Also I'd check your Coil packs to make sure they aren't arching spark to the head, or are cracked up. Also, My car did this too sometimes ( RB20 ) ended up being my Ignitor was dying.

04-18-2013, 08:18 PM	#5
Con-city_s13 Join Date: Jan 2012 Location: Concord, NC Posts: 43 Trader Rating: (0) Feedback Score: 0 reviews	Well I actually did some research on my maf, engine and ecu. I found out I have a cefiro rb20det with r32 maf and computer. I am going to try and find a cefiro maf and reflash the r32 ecu to match all of the sensors on the engine. Just to be thorough, I have checked vacuum lines, tps, and coils.

04-18-2013, 08:23 PM	#6
Con-city_s13 Join Date: Jan 2012 Location: Concord, NC Posts: 43 Trader Rating: (0) Feedback Score: 0 reviews	I also no longer have the no start issue, but it's still in and out of limp mode. Also, I have charging issues as well. The alternator will pass every bench test I can give it, but fails to charge the battery when on the car. Possibly can be solved with an ecu reflash to match the engine? This one is really stumping me because I dont want to replace it w/o knowing it's bad.