Cylinders 2, 4, and 6 are running incredibly rich according to the spark plugs, they are very black. The spark plug wires for each of those cylinders are at around 13,000 ohms. Cylinder number 5 is running pretty rich but the plug has a pretty clean spark area. The spark plug wire for 5 is at about 10,000 ohms. Cylinders 1 and 3 look like they are running very good and there is very little, almost no black on them at all. Plug 3 has a little bit of black on it but not much at all and that wire is at about 8,000 ohms. Spark plug 1 has no black at all on it and the wire for it is at about 7,000 ohms. Any ideas on this?

 

Change the wires?

 

(stupid 10 letters...)

 

the wires are brand new. they probably only have 5000 miles if that on them.

i have bosch plugs in there. should i maybe try some ngk's? i'm reading a thread about someone needing an maf and one guy was saying something about bosch plugs messing with the ve's coil packs. maybe they will do something similar in the vg...

 

yes. get NGKs

what brand are the plug wires?

 

I was wondering that same thing myself after I read a few posts on bad reports on the bosch plugs with the ve's...I installed those suckers a few months ago...does it have a bad affect on the vg's as well?

 

hm... probably bosch wires.

i'll find out if the bosch plugs mess with the vg. i'm going to go get some ngk's tomorrow.

 

I wouldnt worry about the plugs messing up stuff, but what kind of Bosch are you running?

If anything just snag some NGK V-Power Coppers and see how it works for you.

As for the plug wires, have you considered upgrading your coil? you've got that snazzy MSD 6AL, but to really put the Icing on the cake you should try to get the blaster 2 coil (or probably blaster ss in your case). Assuming everything else is perfect or has constant variables, it points to the stock ignition system not being strong enough for the 13k ohm wire, but then again that could be w/in stock specs. just some ideas.

 

i'm actually thinking about upgrading the coil. i actually don't have the msd on right now since i tried getting everything down to the basics to find out what was wrong then start adding stuff when it started to work. i'll get the v-powers tomorrow, possibly grab a nice coil, and hook up my msd and see if that makes thing work better.

 

I dont have the FSM handy right now, but is that 5th plug wire within spec?

also what plugs are in there now? bosch coppers, platinums, +2, +4's? just curious. MSD = FUN+++

 

i think resistance shouldn't be any higher than 25,000 ohms. i have bosch coppers.

that msd 6al is amazing. i pulled all of the plugs out then pulled the distributor out and spun it. it was a pretty weak spark with a small popping sound. hooked up the msd and the spark was a brilliant blue with a very high pitched tone when they sparked. it was fun! lol.

 

Capacitive Discharge baby!!!!!


also you can wire it to provide yet another kill switch (if you dont already have the fuel cut switch). Assuming you wire it the same way I did on the mustang, it will be the white wire, but either way it will tell you in the instructions. It's also a nice feature when you go to take compression tests.

 

the way i have it wired it will be the purple wire. now i just have to decided where i want the switch... lol.

 

Would you happen to know what size injectors were originially on your jdm vg30et? How did the car run with the afm unplugged?

 

I think they are 259cc but i'm not positive. It seemed to run better with the afm unplugged but i swapped afms and didn't get a code so think it's all ignition related. i cleaned the plugs off and regapped them but i haven't had a chance to test it yet because my battery died. it's charging at the moment.

 

Sure the timing is correct? are you back to running the original maxima sensors and injectors on the original ecu?

 

i have the maxima sensors, injectors, and the ecu installed right now. the timing i'm not sure about. last time i checked while it was backfiring and such it hopped around too much for me to read.

i cleaned off my plugs and charged the battery and it started right up but when it tried to idle it sounded like it was missing. i tried installing the msd but it doesn't seem to want to work. i checked all wiring and made sure everything was setup correctly, and it was, but it still wouldn't work. i just love how stuff goes bad on me when it just sits there...

 

Have you checked to see if you have a leaking injector????
You should also check the compression.
Black plugs mean the cly is rich, to much gas to burn completely.
Also check for vacuum leaks, and check the O2 sensor to see if it's carboned up.

 

its not uncommon for the spark plugs to be black when your first firing off the engine/getting it timed/etc. Hell I had nice black plums of smoke coming from the mustang for the longest time when going WOT, or just after lots of cranking/etc.

mt- I'll try to diagram out the MSD hookup today, then we can compare how you set yours up, and how I would set mine up (should come out the same), hopefully the problem will be in with the wiring and not having the actual box be defective. IIRC, I believe you mentioned you got a good deal on it, but you might not have a warrenty anymore

also, what all have you replaced on the ignition so far? did you get new wires or anything? hows the cap and rotor look (just to cross it off the list)? Also are you making sure your using the base timing procedure (normally means unhooking the vacuum advance, if there is one). Lastly the most fun, are you sure the distributor is installed properly? Have you checked it for shaft play or anything like that? maybe its just off a tooth?

If anything, maybe just crank cylinder 1 to Top Dead Center (after the compression stroke), note where the crank is by using the timing marks on the crank pulley, then mark the distributor and rotor positions (so you can put it all back just incase). Uninstall the distributor, line everything up and reinstall it. Then check the rotors position, line the rotor up with cylinder #1 on the cap and hook everything back up. Just make sure that the engine is at TDC, and give it a shot. If no sucess then just put it back to the other way you had it. Remember to take into account that it is supposed to fire at 15* BTDC, but this method should atleast get it running, or fine tune as needed.

You probably already know how to do all that, but atleast now people can search for it

again, make sure your in base timing mode!

 

ok, I just did some reading and found out/confirmed some things, I'll just write it out so other people can learn from this too. Basically the VG's distributor only serves one purpose, to deliever the spark to the correct cylinder within a specific time frame. It appears that it cannot advance the timing mechanically or by vacuum, and it does not have any triggering device in it to signal the coil/etc. The ECCS tells the coil when to fire, so in that regaurd I believe you have some room when your installing/alligning your distributor because then the ECCS would take care of fine tuning the timing. From the FSM:
So with that inmind, I would make sure the engine is at 15* Before Top Dead Center then I would align the cap and rotor so its dead even if not maybe alittle on the advanced side (because of the Multiple Spark from the MSD Unit), and give that a shot.

Also the FSM states:
So I'd make sure your battery is fully charged, but really consider making sure the altenator is working properly, or take the steps to replace it. It's just one you can cross off the list of factors that could make the act the way it is.

[edit]Well damn! The FSM says that in order to adjust the timing on the VG you loosen the bolt which secures the distributor, then rotate the distributor until the desired timing is obtained. Arg, I thought thats how it worked in the first place, so I guess the ECCS/ECM doesnt do as much as I thought it did in the timing department.[/edit]

 

Ok, heres what I came up with for Wiring the MSD 6 Series Ignition Control Box to a 89-94 VG based Maxima.

Primary Red (10gauge): Positive Battery Terminal
Primary Black (10gauge): Ground
Red (16gauge): Connect to the white wire with a green stripe, which is currently connected to the positive terminal on the coil.
Orange (16gauge): Connect to the positive terminal on the coil, which currently has a white wire with a green stripe connected to it.
Black (16gauge): Connect to the negitive terminal on the coil, which currently has a light green wire connected to it.
White (16gauge): Connect to the light green wire, which is currently connected to the negitive terminal on the coil.
Violet (16gauge): This wire is not used.
Green (16gauge): This wire is not used.

So after every thing is completed, the white wire with a green stripe, and the light green wire will not be connected to the coil.

To check for spark:
1. Make sure the ignition switch is in the "Off" position.
2. Remove the coil wire from the distributor cap, and place the metal terminal approximately 1/2" from a ground.
3. Disconnect the White (16gauge) wire from the negitive coil terminal.
4. Turn the ignition to the "On" position.
5. Tap the White wire to the ground several times. Each time you pull the wire from the ground, a spark should jump from the coil wire to the ground. If the spark is present, then the ignition is working properly.


-MrGone

 

the cam position sensor is in the distributor itself and that's what the ecu reads to fire the coil when needed. the ecu does control the ignition quite a bit because i've pulled out my distributor many, many times and have made absolutely sure that the timing marks lined up. i would then take the timing light and make sure it was close to 15 degrees btdc but last time i tried the timing jumped around so much i couldn't tell where it was at. i'm pretty sure i have it anywhere from 15-20 degrees btdc but i'm going to check it again when i get it running smoothly.

i grabbed my uncles christine (i think that's just who makes it but that's what my dad and him call it) to check my battery charge and condition and the alternator condition. batter was kind of low but the condition was good and it also said the alternator was charging properly so that is out of the way. i'm almost positive now that the initial problem of it running badly and backfiring after installing the alternator was due to attempting to run it off of the battery. it got to where it almost wouldn't run and i had to keep giving it gas to try keeping it running. i bet what happened was since the voltage was getting low my spark power was probably really low and didn't burn the gas very well in turn coating the plugs with the good ole nasty black stuff. i think now with new plugs and re-checking the timing it should run pretty good.

i have the msd connected exactly like that. i'm going to check to make sure i have voltage on the 10 gauge red wire and see if i have continuity on the 10 black wire with ground because i've done the check with the white wire and i didnt' get any spark so it's either the unit itself or it's just not getting any power.

i also need to test my injectors which i think i'll do by unplugging them and listening for changes in engine sound. the back ones i can do pretty easily but the front ones i'll have to use some wires with alligator clips on them but that should work.

 

had a pretty good night. got some good stuff done. i think my msd might be bad but i'll try finding a way to test it. here are some updates:

my dad wanted to rig up some way to test my turbo injectors so we hooked some stuff up to where we had a garden hose running to the injectors. we then took a batter and had some wires with gator clips on both ends. hooked the wires up to the injectors and tested them all. out of 6 one was bad (cylinder number 5). since we had nothing to loose my dad took a drill bit (not to drill anything) and pushed on the pintle. it took a lot of force but the pintle finally broke free and it started to let water come out. we hooked the hose up to a hot water supply and put some soap in the hose and started running it through the injectors. i made sure they were all flowing somewhat decent. after about an hour or so of doing this i finally dried everything off and went to install the injectors. about another hour later i had them all in and everything back together. i put in the chipped ecu and the new plugs and tried starting it up. it started right up but then immediately died. i turned the key off and waited a sec. i turned it back on to let the fuel pump prime the line and started it and it started right up and kept running. the idle still sucks but it revs pretty well. when the high idle kicks on it runs very smooth but once it turns off it runs like crap and doesn't want to idle. it will rev pretty well and went right up to 4000 rpm pretty easily. i still wasn't getting a good air flow reading on my s-afc so i took of the piping from the turbo and put the afc right on the intake manifold. it seemed to rev much easier but idling still wasn't too good. i think i still have some ignition stuff to deal with and i think i have bad gas also (in the car, not me). the piping for the maf that is before the turbo kind of sucks and i think that's the reason for it not getting a good reading. i will try fixing it so it will sit on the piping better but if all else fails i'll have to try putting the maf after the turbo which usually isn't a good idea but i'll try it.

a bad thing i found is my turbo may be going out. there is some oil in the compressor housing so that kind of sucks. there should be some life left to it. i may try getting that t3/t4 for 400 dollars that was mentioned on here.

 

look at the end of my last post for the instructions on how to test the MSD.

what kind of characteristics does the idle have? Does it just keep bouncing around like 500-1000rpm or so, or does the engine studder and get all rough like its misfiring or something, just lots of viberations and whatnot.

One thing I figured out with my car is that actually driving it around worked out a bunch of kinks. I was having a combination of all the idle problems I mentioned above, and I traced them back to the VTC's being grounded (when I would unground them, it would run perfectly). Needless to say, the car had lots of idling time while I tried to get the engine to adjust, I went threw atleast a quarter tank of gas just on the driveway, but then after driving it around abit (about 11 days now, 375miles) and the idles been smooth and steady, except once or twice it gets jumpy, but it only happens when I hear the VTC's when the car starts up (haven't completely figured it out yet).

Because one of the initial problems I had was the car didnt want to drop below 1100-1300rpm idle at full operating temp, I drove the car around a local parking lot for 10mins or so, in first and second gear and I would force the car down to 500rpms or so, with one or two times down to 300rpm just to try and see what kind of reaction I would get.

I know you dont have VTC's and such, but it might help to just get out and drive it around abit.

 

yeah, i've tested the msd like that a few times and had no spark at all.

right now, the idle is rough and when the high idle isn't on it will slowly decrease revs and just die. i actually just go back from driving it around a bit. that was pretty hard to drive, lol. while trying to drive it won't rev very well at all. you have to keep the throttle down or keep blipping it to get the car going. i probably took many miles off of my clutch as well since it wants to die when it is below 1000 rpm.

i think my entire problem is timing. i know i have air entering the engine and I know I have gas entering the engine so that leaves everything down to spark. i may grab a new cap and rotor today and i'm going to put a known good coil on there. if those don't help i'll have to take the distributor out and test the cam position sensor. hopefully it's not bad...

 

One thing you have to do is make sure you have no leaks on the intake anywhere after the afm. Just one vac fitting being off or a small leak somewhere after the afm on the intake piping will cause similiar problems. When I unplugged my fuel canister I didnt plug the vac line that ran too it and the car ran like ***. Soon as I plugged the leak all was well again. Have you tried using starter fluid or propane to detect leaks. Its not the safest way but it works.
I have a feeling if the car runs at the higher rpms your timing is not off enough that it wouldnt idle. What happens when you rotate the distributor to the as far advanced or as far retarded as you can go? Any change in the way it idles?

 

i can't seem to find any more leaks using my cigar method. i was going to try using CO2 to detect a leak since it should make the engine bog down a big but I need to figure out a way to release it out of a paint ball gun canister.

On the distributor, should I be able to take it past top dead center? If so, how much further past can it go? Reason I ask is I'm at about 15-20 degrees btdc and there is not much more play to get it closer to tdc (not that I want to get it there though). Also, when revving it revs pretty well to about 4000 rpm then kind of slows down when going higher than that. It revs well but not as fast as it should which makes me think timing is off.

 

I still think its a vac leak. I suppose the c02 method would work but i still think it would be easier with starter fluid. Just keep it away from open sparks so you dont burn your eye brows off. Just an off the wall thought but there are two holes in the back of the compressor housing for a heatshield support that gets bolted on. If you dont have the bolts in the holes they let in air so you might want to check that.

As far as timing, I would just rotate the distributor as much as you can each way and see if you notice an improvement. There really isnt anyplace else to mess with timing. Maybe pull the distributor and try moving it by one tooth each way and see if it makes any difference.


Did you ever get it to run right on the stock injectors and ecu? At this point I would remove as much of the extra ignition related stuff as possible. You dont really know for sure if the tuned ecu has the correct fuel maps so I would put the stock ecu and injectors back on for now. You mentioned you have a avc or something, I would disconnect or disable that for now as well as the msd. Atleast with those items gone you can narrow it down to something directly engine related. There is no reason the car shouldnt run perfectly on the stock setup unless it was bad to begin with. Once you get it running right with the stock stuff you can start putting the goodies back on and find out whats screwing you up. Did the stock ecu pull any error codes?

 

yeah i had all of the stock stuff on and it ran the same. i had every add on disconnected as well. i'll check for those holes in the compressor but they shouldn't matter too much since i now have the maf after the turbo. i found out from someone that the maf has to be at least 18 inches away from the turbo to get a good reading. wish i knew that before i set the maf up in front of the turbo, lol.

 

Did you just install the turbo????
Was it running good before you did the mods???

 

if i'm understanding your questions correctly, the turbo came on the engine and i'm not sure how the engine ran before i got it because it's a jdm engine.

 

hmm... noticed something funky tonight with the fuel pressure gauge. when i turn the key to the on position for the fuel pump to do it's pressurizing thing the fpr will read the proper pressure that i have it set to but when the pump shuts off fuel pressure drops to 0. shouldn't it hold pressure?

 

You might have found the problem. It should hold pressure. Something is leaking fuel. Pump sounds ok, but check everything.
You might have a bad fuel pump, regulator, or injector. Try this:
First check for fuel leaking. If not continue.
Find the rubber fuel pressure line under the hood. Remove it and install the pressure gauge to it.
Turn on the key, don't crank the engine, see if the pressure stays up.
If it will the pump is good. If not the check valve in the pump is bad, change the pump.
Reconnect the line.
Remove the spark plugs.
Turn the key on and off a few times to pump fuel into the system. Don't crank the engine.
Pull the fuel pump fuse.
Make sure no open flames around and have someone crank the engine. If you see fuel coming out of a cylinder, that injector is leaking. Replace it. If no fuel the injectors are ok.
If still will not hold pressure, put back the fuse and plugs.
Pinch off the rubber return line, turn on the pump, don't crank the engine, the pressure should stay up. If it will replace the regulator. If not go back and recheck, you missed something.
Hope this helps.

 

I know the fuel pump is good because it will hold pressure while the engine is running. I have a fuel pressure gauge so I know that for sure. I'm pretty sure the injectors aren't leaking because I cleaned them recently by hooking the rail up to a garden hose and pumped soap through them and stuff. While i wasn't pulsing them there was no leaking from any of the injectors.

One thing I am thinking is the fuel filler tube recall. I was running battery cables to the trunk so I could put the battery back there and noticed the seat belt thing was completely rusted off. No longer safe for anyone to sit there now. I'm thinking there could be a hole in the filler tube which won't allow there to be any pressure in the fuel tank. I think that could be the reason the fuel system won't hold pressure. I really hope there isn't too much rust damage though. I don't want Nissan to tell me they won't fix the car after doing all of this work.

 

As abunai said, it could be a back check valve in the pump.

The pump will still pressurize but if the check valve is bad the pressure releases as soon as power is cut to the pump.

Follow his diagnostic instructions and determine the true cause of the problem.

 

90

 

dang... i hope it's not the pump. it's a new walbro 255 lph high pressure pump. i'll look around tomorrow and hopefully figure out what is wrong.

 

another thing crossed my mind tonight as well.

it will barely idle. sounds like it's missing, it shakes pretty bad and will eventually die. however, when the high idle kicks in it idles very well and very smoothly at 1500-2000 rpm. could this indicate a vacuum leak in or around the iacv?

 

possiably a leak, I'm not entirely sure though. you could try adjusting the IACV though. your cars a 5spd right?

 

yup, 5 speed. however the engine had an auto tranny with it. i swapped the iacv though because the one on the turbo engine had a flat piston thing and the maxima engine had a domed one. i also didn't know of the condition of the turbo one and knew mine was good.

i didn't replace the little valve that was in front of it. should i swap that over too?