I'd hate to just throw out another possibility.. but at this point, you may want to try it.

I had a similiar problem... could be a leaky/stuck injector?
Were any injectors at any time removed..pinched inj o-ring? If not ~ it could just be leaky/stuck open. I believe you can test them with a cheap multimeter. ($3 from harborfreight)

i would say egr.. but that would cause hard starts during cold start ups.
during warm start ups - i would think you would be fine (since isn't its main purpose is to recirulate hot exhaust gases?)

When it happened to me... starts were fine when cold... harder when warm.
I think what happened with the leaky injector was:
1. On cold starts - less saturated cylinder with fuel = easier to normal start.
2. On warm starts - the leaky injector flooded the cylinder after shut off. Since you restart the car without giving it time to "dry/evap" = its causing harder starts.. and would also explain the black puff of smoke coming out due to being rich.

 

Leaky injector could be a cause. How old are your spark plugs? Why not remove & reinstall the spacers as The Wizard stated?

You still haven't really tried to fix this thing, just drawing conclusions with no conclusive data to back up any of your theories.

 

You are NOT running rich due to either the spacers OR the ypipe. You need to quit blaming the spacers for your problem. You are the only one with spacers on a 4th gen having problems. The problem most likely came because of an improper install of the mods, not the mods themselves. You should not have any decrease in mpg after these mods, infact it should increase if anything. And there is NO common reason you would be running rich after spacers if they were installed correctly. Most likely they were not sealed good enough with RTV when installed or you messed up an injector. And by the sounds of the mechanic you had do it, it sounds like having them installed incorrectly or getting something messed up most likely happened. You need to stop blaming the spacers or ypipe and realize its something else.

 

yea i replaced the spark plugs with NGKs in december, and i checked them about a month ago for anything unusual.

and right around the time i started this thread (as opposed to the other thread called "im running rich and its making me poor") we, myself and kenny, had just taken the spacers out and reinstalled them a second time.


so what is it then? like ive said before in this thread, my car was running perfectly the day before the spacers/y pipe install.

actually that is very wrong. there are three people in southern florida alone that have started having strange problems once the spacers went in. i am one.

theres one whos car is backfiring randomly (has a MEVI and spacers and y pipe) and one whos car has nearly the same choking issue i have (just y pipe and spacers - similar to me), except its when he is accelerating at low speeds - he has no starting issues.
one of these guys even has an SAFC and is still unable to correct the problem....

both of them are convinced its the spacers becuase the problems started after the install.


yes, i agree with this. but that doesnt change the fact that my car isnt running properly. and if the person who helped me with the spacers cant figure it out, then my only choice is to remove them and go back to stock to see if the problem changes.

yup

then i would have a jumpy idle, right?

yea this sounds like the most likely new possibility.
when we took the IM off, we actually didnt take it off, we just bent it out of the way. see pics:





do you think that could have damaged an injector by sitting on it?

in this guys defense, not only is he a Nissan certified mechanic who works at a dealership, but he is the top mechanic there - the one they are flying to chicago to train for the GTR and the one they give the "tough" jobs to.
hes no lightweight.
he has owned and modified two 4th gens, one turboed, and has been working on all gen maximas for over 13 years.

he said hes only done one NWP spacer kit install before, and it was on a 6th gen. there were no problems.


anyway. i apreciate all of you trying to help.
i will keep you informed as to what goes on - or what the solution is once i get this to stop happening.

 

If there was direct contact with the injector - you could have possibly cracked it or ripped an inj/oring? (not likely.. but possible) Check with a multimeter. Another easy why is to check the plugs to see if any one of them is fouling more than the others

 

Ok im a little confused, you did take the fuel rail off and the lower intake manifold off right?

Im not doubting his over all Nissan ability but NWP spacers are a new mod that he may not good have experience with. I made my comment based on when you said he 'gobbed' the RTV on.


Also, you say 2 other FL members are having problems, did they do their own installs?

 

i dont think we took the fuel rail off, but im not 100% sure.



yes, as far as i know, they did their own installs.

 

I can assure you that the spacers are not making you run rich. This has been fully tested and by lengthening your intake runners a 1/4", it will not change your AFR.

You mentioned other people having problems. I have not heard anything about this. So far, you are the only person that has contacted me about any kind of issue with your car. If you are running rich, then it is most likely an o2 sensor problem putting you in the safety fuel map. As black_maxed95 mentioned, there are several things you have said that leads me to believe that the modifications were installed improperly. If you do not have an intake leak or a leak from your EGR system, then there is no reason the spacers would be causing your problems. There are a lot of happy people out there that have the 4th gen Thermal Intake Spacers installed without any problems. I just wanted to make it very clear that the spacers are not the cause of your problems.

 

To fully install the spacers the fuel rail has to be removed (atleast unbolted and moved aside) to get to the lower intake manifold bolts. The LIM has to be removed to install the 2 lower spacers. The injectors could have been damaged when taking the fuel rail off...unless you know it wasnt removed then the spacers were not fully installed.

 

A little late to the party, but I'll add that I do agree whole heartedly with the advice and information black_maxed95 and Aaron92SE have stated thus far regarding your most recent questions and comments. I would have stated the same info.

Troubleshooting requires going back over every step with a fine tooth comb, and looking at EVERYTHING that you touched, removed, replaced etc. no matter how big or small/insignificant the step/part may seem.

I'll add a few more comments below.


plus some of the initial troubles mentioned in the first post is what caught my eye...

Point being, everything needs to be checked and rechecked thoroughly by someone with the know-how.

 

i was searching last week about running rich and i came across a few posts from the moderator StephenMax who said his issues came from a leak in his Y-pipe, where it mounts to the headers. this allows excess, unchecked air onto the O2s and causes the ECU to dump more fuel into the system to compensate.

figuring that because i REUSED my OEM crush gaskets (the budget ones did not fit...) when we did the original install of the Y pipe in April, it was time to replace them, whether they needed replacing or not.
l also got some anti-seize for the O2 sensor threads.


yesterday i went to my local shop and began the process. the O2s were a B*TCH to get loose, but once we did, and once we dropped the Ypipe, you could clearly see a big black line of carbon and debris covering about 1/3rd of the opening on the front mount of the y pipe........

ive had an exhaust leak all along.


so we put the new crush gaskets in, reuse the old cat gasket because we dont have a spare, and re-thread the O2s.
i can definetly feel a difference in terms of how "smooth" my car runs, both on acceleration and at idle, HOWEVER MY WARM STARTING ISSUE CONTINUES (i.e. my engine is still dumping too much fuel).

i drove her around for a good 20 minutes and then let her sit for 30 mins before trying to start her up - had the same problem ive been having since April.

i then unplugged the positive feed from the battery and let it sit for an hour before reconnecting it, hoping the ECU would "relearn" its a/f ratio and stop this issue from continuing.

it seemed to make no difference.




is there something i am forgetting to do after fixing an exhaust leak on your car?
did i reset the ECU properly?
how else would i do it?

i also started messing around with the IACV screw, trying to set it back to what it was that day in april (since April ive UNscrewed it alot, trying to increase airflow to the system and balance the problem, so i needed to screw it back down)

any advice?

i feel like im close to fixing this.

 

After the PM you sent me and reading this entire thread, I have a few things I'd like to mention. I myself have had a slightly similar problem with starting, except that it mostly is just that the starter keeps turning over and doesn't start the car until after about 10 seconds. Then I turn the key off and try again and it starts right up. This is when the temperature outside is warm, not necessarily the engine. I'm not sure if it's the same problem as yours, but I'd still like to help diagnose if I can. One more thing, I don't have any engine mods on my car, I have cleaned the UIM and EGR a pretty good while back, and I've changed my fuel filter to a 300ZX filter. I do know that my battery terminals are cracked and corrode quite frequently, so I will try changing those when I get some money together. Keep me informed if you do fix the problem though.

P.S.

I did have an EGTS code a few weeks back, but after clearing the codes, it hasn't come back.

 

i apprecaite you trying to help here man. it doesnt sound like we have the same problem.

i replaced my plugs with NGK platinums in november 07, my airfilter and fuel filter are new (the 300zx tt one) as of january.


plus, all of these problems just started happening the day after the y pipe/spacer install.

well, as i found out yesterday, my y pipe was leaking air the whole time, which would explain my poor gas mileage, and should help explain the warm starting issue.....but it seems to still be present.

and the best description of the starting issue is as follows:

when my engine is hot and i let it sit for 30+ minutes, when i go to start it, it chokes and seems to stumble once it ignites.
the turnover is fine, the starter clearly has good power, but the "breathing" of the car is impaired for the first second or two. it rumbles, as if there is too much fuel in the system and cant burn it all evenly.

when my car sits for 5 hours or more though, it starts fine.
it also starts fine if i turn it off (when warm) and turn it back on immediately.




you said you had an EGTS code?
do you mean ECTS - engine coolant temperature sensor?

quite a few people have recommended that as a potential fix, but i dont see how that would have happened to die the very same day as putting all these mods on my car.


also, this is to everyone,

could this potentially be a result of the NEW charcoal cannister valve we put on my car that day?
as i understand it, that regulates fuel vapor in the system.



or this starting issue a direct result of the leaking header/y pipe mounting point?

 

I did mean to say ECTS code. Mine does kind of choke a little after the first turn of the key after the 10 seconds of waiting. My starter may be on it's way out as well. Who knows, it could be a different problem altogether.

 

While dealing with my alternator issues. I've cleaned/re-sanded all of my grounds (including the additional ones that i've installed)...and of course the biggest ground (the neg batt terminal that connects to the engine). I also have a brand new starter with a nice ground wire running from the starter bolt to the chassis. I'm sorry to say that it hasn't cured our problem. I just add a bit of gas, and it works fine. (meh)

 

You really should change the ECTS, it's cheap & easy! It might solve your problem.

 

I've been saying ECTS for the last few months, it's like 27$ and 5 minutes.

 

yea i know. thats my next step


i ordered one from dave b litterally 45 minutes ago.

 

There...there....NmexMAX, you'll still get the credit!!

There's also a running theory about loss in fuel pressure caused by leaking injector(s)
(not to mention the flooding/poor gas mileage). If that's the case, I REALLY would just leave it alone then.

 

even tho i just spent $24 on a new ECTS , and will have it installed by this time next week, that seems to be an issue closely related to weak COLD starts, not warm starts.

anyway, ill report back once its in and i drive around a few times.



also, related to this is, im sure im going to lose some coolant in the process of swapping ECTS's....
is a coolant flush or drain/fill recommended at this point with only 52,000 miles on my car?
if so, should i just regular coolant to replace it? is there any special nissan kind or best overall brand?
and the ratio of water to coolant is ALWAYS 50:50 right?
what is the capacity of the coolant system?

and yes i know to use distilled water.

 

i'll come forward as one person who had a starting issue immediately after a spacer install. Fortunately I was able to diagnose and fix the problem before i could notice the trend but it would start up but only jump to 3-400 rpms for a second then just die, after the second crank it would stumble to idle rpm and stay. everything would be fine after then. I even had it shut off a few times after throwing it in neutral while coasting to a stop (which never happened pre-spacer install)....which led me to IACV, i adjusted it and everything is perfect now. Im not saying the spacers caused it, but maybe somehow the changes made by the spacers affected the iacv and it just needs a little adjusting.

 

ommfg dude.......wyere have you been ??? lol this is the EXACT problem i have...weak, stumbling starts when the engine is warm.

what did you do to the IACV?
did you mess with the screw?
which way did you turn it ? in (clockwise) or out (counterclockwise) ??

i just spent $140 on parts from dave B....

two battery cables (pos and neg)
two IACV gaskets
rear main cat gasket
two EGR tube gaskets
ECTS unit....

 

well, i first began by screwing the black screw all the way down (iirc thats clockwise). idle should be at its lowest by then. i just unscrewed it until the idle got higher pretty much. id probably say about half way unscrewed is where i have it. just play around with it and find the right spot. that seemed to do the trick. got rid of my hard starts and the car shutting off issue.

if that doesnt work for u and ur getting sick and tired of the hard starts try adjusting the throttle screw to raise the idle a tad bit and see if it helps any (not sure if it would tho), atleast until u find the real cause.

 

It is WIDELY known on here that a faulty ECTS = hard WARM starts.

 

WELL AFTER 5 MONTHS AND $2,000 IN "WASTED" MONEY I FINALLY FIXED THIS ****ING PROBLEM - and you wont even believe how stupidly random it was....


Last weekend, at the behest of various members here, not to mention Kenny, the mechanic that helped with this install in the first place, I paid the $50 something dollars to replace my ECTS and clean my IACV.
The IACV I had taken off and cleaned before, but I have never removed that gold cap, nor had I cleaned the actual valve. So I took those apart, did a good job on all the parts and reassembled.....still had the same problem.

Then it was time for the ECTS. I was paranoid I would lose a bunch of coolant in the process, but litterally none came out except for the few drops on the actual sensor.

I REALLY REALLY hoped this would solve the problem (even the Haynes manual says to check it for warm starting issues), but it did absolutly nothing.

 

I also checked in the EGR area, to see if there was any significant buildup but there didnt seem to be anything. I took a shot for you all just in case i missed it....


its noteworthy that while i had my head down around there, attempting to look into the EGR, i smelled a VERY STRONG SMELL OF GASOLINE. i checked all around the fuel lines, checked the filter area, but didnt see anything wet or otherwise out of the ordinary.






The next suggestion was poor electrical connnections. I had already mentioned that my battery cables, both pos and neg, were severly damaged and corrorded, so I dropped the $130 on a brand new set from DAVE B.
Installation was SO MUCH MORE DIFFICULT than I had imagined - mostly because of the corroded connections, and rusted-on battery tray...







and how the **** did my air filter get so dirty after only 3000 miles?

it smells burnt??

 

so, pretty much my last shot at any kind of reasonable idea for fixing this goddamn problem was a leaking injector. and the reason i didnt take this that seriously back in April (when i first started trying to diagnose my problem) was that all of my plugs seemed consistant when i pulled them looking for one that stood out from the rest.

I honestly didnt believe it would fix anything, but I had to try...
so i ordered a new set of 18 injector Orings from DAVEB and set up a time at the shop to start the process.

we pulled the injectors and both they AND the seals looked fine as far as i could tell. a couple had broken teeth here and there, but nothing looked cracked.

 

and the old orings





so we pulled them out, pulled the rail, and began to look around....




WELL LOW AND BE****INGHOLD, THERE WERE GOBS AND GOBS AND GOBS OF RTV BLOCKING THE SPRAY FROM THE INJECTORS. IT WAS ****ING OBVIOUS.






my guess is that kenny used such a plethora of RTV on the lower intake spacers, that it squeezed out the side and was blocking the injector spraying area.
now, when the injector was spraying gas onto the RTV, it would sit on/around it and slowly drip down into the cylinder as the car sat, thus flooding the engine when i went to start it after a 20 minute rest.

however if i let it sit for 8 hours, the small amount of gas would evaporate, and the problem wouldnt present itself....


im so unbleiveably pissed that it has cost this much time and effort and money to fix, but in the end im just glad its fixed.

 

anyway, thanks for all of your help guys.
i know i got pretty subborn and cranky at times, and i appreciate you all continuing to try to help.


here is your reward .....

 

Thanks for the update. That is BY FAR the most RTV I've ever seen squirt out in the airflow. It is definitely evident that there was an obstruction in front of most, if not all, of the injectors.

A good indication that too much RTV was used can be seen on the outside of the intake manifold. If you see any RTV squirt out when you initially press the spacer down with your fingers, then you used too much. You should not see any RTV squirt out even when the manifold is torqued down.

But I am happy that you fixed it and your car is running smoothly now. It definitely pays to have a good mechanic that knows how to follow the installation instructions the first time.

On step 30 of the NWP Engineering Installation Instructions for the VQ30DE Thermal Intake Spacer Kit, it says to be careful not to use so much RTV so that it squeezes out and obstruct the airflow. And in this case, it was not only obstructing airflow, but preventing a proper injector spray.

But I am glad you finally got it figured out. Are you happy with the ypipe and Intake Spacers?

 

yes, very much. my car is a little jumpy (can feel it in the brake pedal) when im sitting in idle, but im sure its that same issue of too much RTV obstructing/distorting the spray.

just so it is clear to readers - THE NWP SPACERS WERE NOT AT FAULT FOR THIS ISSUE.

it was caused by a skilled, but rushed mechanic who did not install them properly.

 

Your "skilled" Grand Master Tech should have:
a)known better to goop on the RTV. If not then...
b)read and followed the darn Spacer instructions. Also he should have...
c)not rushed the job

Don't mean to beat a dead horse here, and I hate to say it ROCKART, but several of us called it. Improper installation. We also advised you to retrace your steps (or should I say have the mechanic retrace his steps) before going off on a wild goose chase and ordering parts and 'fixing' things.....

Hope the readers learned a valuable lesson from this story, I know you did (a very expensive one indeed). I'm truly glad the problem is finally solved and you can now enjoy and appreciate your Max and recent mods.

What's your next mod, and who's going to install it?

 

im done with performance for at least a decade....

my next job will be a drop (tokico blues and H-techs ?? opinions?) and thats it.

then the rest will be cosmetic:

1) repaint front and rear bumpers (stage 2 pearl paint ftl)
2) replace and/or clean nasty seatbelts
3) repaint and/or replace fading passenger side airbag
4) replace LCA bushings with ES bushing set (not cosmetic i know)

 

lol. I figured you'd say you're done with power mods for a while....

Let's hope your future suspension doesn't get installed wrong...

 

yea ive actually been having nightmares about my new suspension squeeking uncontrollably...

ill be sure to harass you with PMs prior to the install so you can give me some advice


what are your opinions on tokico blues and htechs as far as a moderate drop with a soft touch?

 

WAAAAAAAAAAAHHHHH!!! why didnt i ever think of that. i rememeber when we were doing the IAVC on our cars thinking....man thats a lot of rvt on that intake manifold......ugh... i feel so dissapointed in myself......


BTW I TEST DROVE THE SKYLINE!

 

and youve seen my h techs with blues set up! its drives beautifully....except for my broken strut mount......

 

thats sick.

is that from your new job? how is it

 

+1

And also this is a reason why I believe you shouldnt mod a car unless you can do it yourself. Otherwise you pay alot of money having others fix problems that arise from issues that pop up.

 

I was stating this all along that you might have had the problems because the spacers were installed on wrong,well the silicone was smeared on so that It just fell into the hole of the injectors way. The good thing Is that It was not that serious,if you had to take the whole engine apart and go on up that would have been some serious time and money. Good luck and enjoy the mods now.