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View Full Version : CRAZY Issues with rb20det WONT REV!!

twistex
07-30-2009, 01:33 AM
Ok I know everyone will say check your afm, maf or what not. It all started when I was driving the truck one day and the car started to buck. Pulled over to find out the maf wires had rubbed through on the firewall. yes there was some exposed wires. I taped them up and the truck would still not rev up. I figured i would just buy a new maf and that i had fried mine.

I got a new j60 maf and installed it. The problem still there.. just bounces off a very low rev limiter. I then changed computers, still same issues. I then changed the cas, same issues. I also tried to run a N62, Q45, and rb25det series 2 maf and retune the rb20 ecu still same problem. I then used a rb25 computer and maf, still same crap.

I have no clue what to do. I took the whole wiring harness out of the truck and going to go over it all and double check everything. From what i thought was a simple maf issue has turned into my worst nightmare. I have also rewired and ran all new wires to the maf outside of harness right from ecu plug. Still same thing. I have double checked knock sensors and all other wires. Only other thing i noticed is the o2 sensor wires that ran in same area as maf had been broken from rubbing also.

Does anyone think a bad ignitor could be causing a computer related rev limit ? I know its not mechanical.. its the same exact thing every time. If anyone has any idea please let me know.


Thanks
GSXRJJordan
07-30-2009, 03:05 AM
Your coilpacks can certainly cause those types of problems, it's very common with high-hp RB's - if the igniter housing is cracked, can certainly cause those problems also. Try wrapping some electrical tape around the igniter and the coilpacks and see if that solves it for ya. Then you'll know you need to replace something.
twistex
07-30-2009, 11:59 AM
I will give that a try. You see it does this problem no matter what I do. i cant even drive the truck otherwise it just hits that low ass rev limit. Last night I took the complete wiring harness out and redid everything and triple checked all the connections and taped the harness up. I going to put the harness back in and hook up everything like factory again and hope for the best. The last few things i can think of is coil packs, ignitor.. its not throwing any codes.
twistex
07-30-2009, 03:19 PM
I just tried a couple different mafs and tried to retune and it just still gives me code 12 for maf. The rev limit is at 2500 it just bounces. I can retune ecu to have 1500 rpm rev also so the ecu is working as far as i can tell. I just didn't want to keep reinvesting money into mafs and ecus if I cant fix the issues.
twistex
07-30-2009, 06:55 PM
ok i know you all not posting .. but i fixed the issue. what it was is originally the wires on maf were rubbed through and grounding out. this cause the ground and signal wires to get fused together somehow in the shielded wire. I ran new wires and truck runs titilisous.
GSXRJJordan
07-30-2009, 07:16 PM
ok i know you all not posting .. but i fixed the issue. what it was is originally the wires on maf were rubbed through and grounding out. this cause the ground and signal wires to get fused together somehow in the shielded wire. I ran new wires and truck runs titilisous.

Nice, glad you got it figured out... I was gonna say, if it's throwing a code for MAF, no matter what's causing the code, it'll still run in 'super limp mode'.

:2f2f:
steve shadows
07-31-2009, 07:15 PM
its a boost leak or your engine harness is totally fed