PDA

View Full Version : Help Me Get My RB26 Running


Marino.
06-04-2013, 07:50 AM
Hey guys, so ive been working on building an rb26 s13 for alittle over a year now. I got it to start but its running pretty rough. When I first start it, it runs pretty smooth, but the hotter it gets the more eratic the idle gets. It starts haunting and jumping from 1500-2500.

Heres a list of things done to the motor. I did a full rebuild on it.

-R32 RB26 Came with hks cams, osgiken? cam gears, and tomei timing belt
-Used a different block then the original because it had pitting on the walls
-The block was ball honed
-Stock pistons/rods with new oem rings
-ACL bearings
-Brand new R33 "n1" crank
-N1 oil pump with spool gears
-Cut and welded rb26 oil pan
-tomei oil pump baffle with greddy drain bolt
-n1 water pump
-new timing belt tensioner and idler pulley
-HKS timing belt
-Head was taken apart and inspected
-exhaust ports were ported to remove factory limiter
-reused hks cams that came with the motor 256 9.0/256 9.0
-arp headstuds
-factory turbos, rebuilt with steel wheels
-ebay or obx elbows, not sure got them used
-factory intakes with apexi filters
-mckinney downpipe with test pipe and dmax catback
-brand new coolant temp sensor
-all factory hoses replaced with silicon ones, including the vacuum lines under the plenum
-new wirespecialties harness
-All factory gaskets used as replacement. Certain ones coated with copper spray

Thats really it as far as the engine goes. There was a shitton of stuff redone on the car in the process, but nothing that should effect how the motor runs. Only thing that might is that the harness is tucked with relocated fuse box

And now a few pics
http://imageshack.us/a/img560/7861/20121111231948.jpg
http://imageshack.us/a/img10/1421/20130306000251.jpg
http://imageshack.us/a/img194/2707/20130527193819.jpg


My concerns
-When I take it out for a drive it feels like its missfiring. I know im getting spark, so I put a noid light on my fuel injector harness and im getting a weak pulse, almost doesnt even light up the noid light. So i test the resistance on my injector resistor pack, and im getting 6.5 ohms, while the factory says approx 5 ohm. Now im not sure if nissan considers 6.5 approx 5. I also ohmed out my injectors, and theyre getting 2.3ish accross the board which fits into the factory spec of 2-3 ohms.
-Air/fuel isnt even registering, starts lean, then just goes off the gauge. The car also gets hot pretty quick, not sure if this is also do to the possible lean condition.
-I did not degree the cams. I left them the way they were as they came in the motor. The intake cam is slightly retarded, and the exhaust cam is in the factory position. I know it will make a noticeable difference in power, but from what i read on the gtr forums it wont make the car run any different if theyre improperly adjusted. Heres a pic of how they came in the engine
http://imageshack.us/a/img59/3561/20120307213816.jpg
-The vacuum is reading around -14 which isnt the factory -18, but im wondering if thats because the rings arent fully seated, or the cams might be throwing it off, or if i have a boost leak somewhere
-the intake for my rear turbo has been cut shorter to clear the fender tub. so the maf is closer to the turbo. im not sure if this would throw off the reading at all. heres a pic
http://imageshack.us/a/img716/9600/20130407171920.jpg
-I tried a different cas off my friends rb25. While it is a different part number, i heard theyre all interchangeable unless its the new style ones. The car still ran the same.
-I did resync my itbs, and adjust my tps. This made no difference -.-

So anyone have any pointers or tests they recommend? Im kinda leaning towards the injector resistor pack but id like to know some of your opinions

Thanks
-marino

Sileighty_85
06-04-2013, 08:20 PM
have you pulled codes from the ECU? ECU Coolant Temp sensor usually causes issues like that when the engine gets hot

Marino.
06-16-2013, 10:04 AM
Its not throwing any codes, sorry for the late reply.

I found a huge vacuum leak and now it idles smoothly, and doesnt bug out under load. However it idles at 1500, and i cant get it to go lower unless i unplug the temperature sensor. The car nomally idles in the lean zone, but once the sensor is unplugged it runs 14.7 at idle and the car feels better.

I do have a new temp sensor, but the car runs even worse. I got it from frsport and it says its for rb26, but i see that its a different part number than the original.