rb25 starting issue.

[the_momo]

i may just be a total retard first off....but when i try to start the car, it does the clicking thing, like it has a dead battery. so i put it on the battery charger/jumper, and it stops clicking, but it makes a humming noise. like the starter is jammed and its just getting power but no output. any ideas? my dad thought it might be the charger itself. not sure. maybe there is a grounded out wire? or not a sufficient ground? also, i never changed the configuration of the wire and the car ran previously, but the battery ground doesnt go to the block, it grounds on the chassis, should i change it? i have seen both on different cars, and im not sure what works best on the rb. any input would be greatly appreciated. thanks!

[Joe]

take the battery to autozone/checker/shucks/kragen/napa and have them test it.

[the_momo]

yeah thats on the list, my garage is in the middle of nowhere, so it takes a concentrated effort to do such things. ill prob throw it on my dads other charge tomorrow, it has a lot of the little weird settings(like deionizing and desulfiding and such, its a big battery tender thing for motorcycles and boats and such. too smart for me.... ) i was just wondering if there was anything i should look for in particular. i hope its just the battery... thanks!

[Joe]

it could be a ton of other things

but its best to start with the easy stuff first

[the_momo]

well put, ill post results tomorrow, and pics of this charger, this thing is the shizz. like way too complicated for a charger. im proud itll be helping my car, but its like getting a brain surgeon for giving you a flu shot.

[the_momo]

btw, i love those rims, i have them in gm on my srt-4, that is if they are mb motoring weapons. thats what i have. 7x17 +48 in gm. my brakes needed some ..ahem...caliper clearancing. i dont believe in spacers. not for 2 mm. works great tho

[Joe]

yep they are weapons, but in a little more manly sizes. 17x9 +17 all around.

they are cheap, heavy, but strong and hold up to the abuse i put them through.

[the_momo]

agreed. i get a super deal as a friend of mine is a manager at discount tire. my dd doesnt need to be a man, just pretty. id rahter ride a chick everyday anyway. i was thinking about those in gm for my s14, but i dont know yet. i have z32 wheels and they aer just fine for now.

[the_momo]

ok so i got the thing to turn over, tunrs out it was the battery charger. it turons over, but no vroom. i have the timing set according to the fsm. i was thinking it might be the fuel, but it gets gas in all cyl (pulled plugs and all had gas on them.) my q is would it not fire at all if it had insufficient volatge? the plugs looked like they havent fired at all i.e. they had no carbon on them. all the wiring is plugged in correctly. im thinking 1. not enough power to supply the coils, 2. bad ignitor(i hope not), or 3. maybe the plugs arent right(physically too short?) i had none to go off of and i used a pn reference from here. the ones i got were autolites. not 100 on the number at the moment, but they threaded in and were a good height(from what i could see, didnt hit the piston, you know important things like that...) but idk. just lost. thanks

[the_momo]

the plug numbers that i have are ngk bkr5e-11, which on sparkplugs.com references for the rb25de and det. so i have stock plugs. which are the same for most nissans of the era (as i have found from searcing.) the odd thing is, it looks like there not long enough. like they dont engage the coil pack fully. i pulled the boot off and it had the tip and a little carbon looking thing that is spring loaded, the plug doesnt depress the tip all the way. is this normal? im really confused. my poor car just begs for life. i pulled the coil packs and hooked them up so i could see the spark, it sparked out from under the rubber boot, which led me to believe that the plugs arent long enough. odd.....just odd. grrrrrrr

[rbspitfire]

are both relays plugged in and working, can you feel them click when you turn the key on?

[the_momo]

im assuming you are talking about the green ones right? last time i checked they were. ok so this is what i have thus far.

i have spark on all of my coils, so that isnt an issuei have fuel (took of cas and did the spin test, they worked)timing to the best of my knowledge is correct (set at tdc and lined up the ticks on the cam gears.) it tries so hard to start. im about to pull this thing apart and rebuild it totally(pistons rods hg all new wiring i.e. megasquirt standalone etc.) this is getting old. i spent about 2 hours just trying different things. there are 2 open ended wires on the ignitor harness. one is on the out end of the ignitor harness and one is on the out end of the 3 wire harness with power and such to the coils. the one on the ignitor harness is tied into the E slot. ? im beginning to think this is going to end badly. there was evidence of some ..wiring modification done. soem ends with no clips, clips with nowhere to go, etc. im in for soem fun i think. wish me luck. ill let you know how the megasquirt goes, cause im done dealing with the factory wiring. its a nightmare.

[eh?]

unplug your maf and try to start it.

[USMCgetsome]

this is the GO BIG OR GO HOME THEORY. Get a multimeter and get some real results. Don't guess. Find some voltages and grounds through the ecu pin out or simply check the ignition relay for 12vdc on all points of the relay and also the eccs relay.

If your vehicle cranks you can rule out the starter and rotating assemblies. Next is fuel and ignition.

Fuel: check fuel pressure, check all injectors firing

Ignition: Pull a coil pack with a plug and ground it to the valve cover check for spark at all 6 cyls. If you didn't have enough voltage from the battery the alternator would crank sluggishly

I'm sure we can get that baby rolling again soon. Need more help email me at [email protected]

[the_momo]

i printed out the ecu pinout from the fsm last night. im gonna check the pinouts today. also i might have found something. the fsm says the cas has a keyway in it, i didnt see that on the cam, but there is a little groove on the inside of the cas. ill see what i can find out about that. gonna try again today. thanks for the replies.

[USMCgetsome]

yeah man the cas won't mount(sit flush) if the key way isn't lined up. Need to get the rb20det wiring schematic as well and lets get it finished up.

[the_momo]

so good news. i am fairly certain (i have not started it yet...ran out of time tonite, i have a lady that needs attention too.) that i have figured it out.

i looked over the ecu pinouts and tested all of the ones that i thought might be issues (injector leads, coil leads, etc) all good. which is a good thing. then out of a bit of pure genius, i looked into the cas and saw something.....a broken keyway. but, it was broken in such a way that i could super glue it back on. heck, if it lines up right i could care less if it breaks off again. as long as it works. that would explain why i have spark but no ignition marks on my plugs, not igniting on compression, only burning the gas.

so hopefully i can button it up (again) tomorrow and make it run. if not, then im tearing it apart, buying hks cams, hks headgasket, rb26 pistons and rods, and making 500whp.....next year. ill keep you all updated.

thanks again for all the support, it is really awsome of all of you to be so helpful. if any of you all are ever in the ann arbor area, i have a couch and a cold beer for you all.

[wawazat8402]

Im not sure if anyone else did this trouble shooting, but make sure the gasoline has evaporated completely from the cylinders before you ground the sparkplug to the valvecover to check for spark. My ears rang for a good 15 minutes.

[the_momo]

ha ha ive done that before. loud mega.

so anyway i got the ting to fire, but it doesnt stay lit for very long. it revs to 1500 (after starting) then drops off. sometimes it stumbles and sometimes it just dies. i have tried adjusting the cas, not much difference. checked all that i knew to check. heres the thing though. this motor was never ran with an iac valve. the dude just ran the throttle cracked a tiny bit and it worked fine. i have no idea where the thing hooks up as it has an aftermarket intake (the long plenum most rb20's use) and a q45 tb. could i just run it from one side of my charge pipes to the vacuum port on my intake? seems like a "crude" way but mostly what it is, just not packaged so neatly. ill get her soon. oh and i learned something, the fuse for the gause cluster makes a difference on the starting of the motor if it is blown. not sure why, but prob some dumb sensor hooked into that circuit. dunno. thanks for the knowledge yall.

oh and btw, it was the position of the cas that was keeping it from firing, the last owner(or whomever) took off the cas and didnt know the keyway was there, and broke it off. superglue works fine though. pita to put back in with a fully assembled motor though.

[Sil240]

I have the same exact problem with my RB20I have spark, the spark plugs dont look like they are long enough.But I have fuel pressure and no injector fireI'm going to try the CAS this weekend.I know my keywaybroke off my cam but I thought I was sure to put it in correctly.I'm also going to check my green relays I know one was bad so i changed it but the other one i left alone.ThanksHopefully it'll work for me

[the_momo]

mega ultra double time check your cas. that was my problem. i have a 25. the 300zx tt plugs work just fine. should be the same for rb20 if not mistaken, but not sure. check pn in the pn sticky. even if the cas is one tooth off itll studder and hate life. make sure and itll fire right up. if not, then one of the relays id bet. good luck, hopefully you wont need as much as i do to make yours run... (im putting in pistons, rods,rings, metal hg, timing belt and studs. no compression and bad 6 piston. so yeah.)