streetzlegend

iTrader: (2)

Well, I am really hoping it dosnt come back lol. Usually I give it a week of testing before I can conclude that a problem is solved. Next friday I am going to the track, its 1/8 but at least I get to compare my previous PB ET (8.6@83mph). I really want to get into the 7's. I will also have video of this, to share with ya'll.

Thank you so much for all your help ttg35fort, and everyone who replied with their ideas. btw ttg35fort, may i ask your name?

Cass007

iTrader: (34)

His name is Terry.

ttg35fort

iTrader: (2)

I just re-read your post (OK, I'm board ), but all this time I had assumed that the AFR was reading arround 11 at high boost. Perhaps running as rich as the upper 9s is contributing toward fouling out the spark plugs. If it is working fine now with new spark plugs, and the problem starts to pop up again later, that would be your clue to indicate that fouling out of the spark plugs is the problem.

Does your EMS support more than one map? If so, create one map for gas and one map for gas/meth. If not, you should think about getting an EMS that does, one map to use on pump gas alone and one map to use when you have meth on-line.

Alternatively, you can bring the meth on-line at a certain manifold pressure, and only run it on pump gas below that pressure. Then, you can tune the EMS for the appropriate AFR at high boost levels where you are using the meth. Even then, you should have some means of automatically dropping the boost if your meth tank runs dry. Your meth kit may include this feature. If not, I know the Coolingjist Smart Injection controller has that ability, and I beleive that others do as well. The Smart Injection Controller is somewhere around $169, and probably a very good investment to add to your system if you do not already have that capability. You can run your boost controller ground to the Smart Injection Controller, and add a float switch to your meth tank. You can configure the Smart Injection Controller to disconnect the boost controller from ground, thereby removing it's power, when the float switch closes. This will take the boost controller off line and drop the wastegates to spring pressure when the meth tank runs dry.

EDIT: I should have pointed this out earlier, but your spark plugs can provide a good indication of the overall nature of your AFR. When you are running too rich, they get black. When you are too lean, they are closer to white. Back when I started playing with motors, I would tune the carberator using a vacuum gauge and then periodically check my spark plugs to make sure everything was running OK. I would make slight adjustments to the carberator based on the color of my plugs. Technology has come a long way since then, but sometimes the old method of checking the color of the spark plugs can still prove to be useful. In your case, you may be running so rich when you bring the meth on-line that residue is building up on the spark plugs and fouling them out.

By the way, don't throw the old spark plugs away just yet. If the electrodes are in good condition, you may be able to clean them up. Although I have not seen one in a long time, there used to be these little spark plug cleaning devices that would clean the electrodes of your spark plugs, essentially using compressed air and fine sand to gently sand blast them. Then you would clean them thoroughly to make sure there wasn't any residual sand left sticking to the plugs. The spark plugs could then be re-used. Personally, I never had a problem re-using spark plugs after cleaning them in this manner. If, however, the electrodes are damaged, throw them away. Unless you have a lot of miles on the spark plugs, I would lay odds that your electrodes are fine and just need to be cleaned.

ttg35fort

iTrader: (2)

This thread opened my eyes to the fact that with all of the technology that has been brought to us over the years, we (and especially me!), forget to go back to the basics when it is called for. Inspecting spark plugs to analyze a motor has always been one of the cornerstones of tuning until recent years. I even stopped doing so. Sometimes, though, there is still very valuable information contained on the spark plugs themselves. Anyway, here is a chart I looked up that provides good information that helps to provide an indication of problems that might be occuring based on spark plug analysis.

http://www.spark-plugs.co.uk/pages/t.../diagnosis.htm

This link also provides some good information:

http://www.4secondsflat.com/Spark_plug_reading.html

superchargedg

iTrader: (4)

You are now talking to some of the older guys here that used to build the old motors and use the color of the plugs to diagnose problems.You could easily tell a lean or rich condition or a problem with detonation by the color of the plugs.

The spark plugs still tell most of the story on how an engine is running.

Thank you Terry for this post.

ttg35fort

iTrader: (2)

Well, I actually haven't spoken to anybody about this... When I re-read one of streetsleged's posts, it made me think back to my early days playing with motors.

The funny thing for me is that I used to always rely on the spark plugs to tell me how my tune was. At that time, I don't think dynos were as prevalent as they are now, and even if they were, I couldn't afford one. My friends and I tuned our motors using a vacuum gauge. We would tune it go get maximum vacuum, then add a little more fuel to make it just a little richer. When we had our cars running, we would pull the plugs out, look at them, and then adjust the screw on the carberator to add or subtract fuel based on the color of the plug. That's the way it was.

Now we have AFR meters, etc. Not that they weren't avialable then, but we couldn't afford them. But in the analysis, the first thing I should have asked is "what color are your spark plugs?" I just assumed that the overall AFR was OK. But now, I don't think it is, and the color of the spark plugs would have told us that.

Although I don't like to admit it, I'm probably older than you think I am. Depending on your age, I may have been building and tuning motors before you were born... But then again, you could be an old fart, I don't know...

One piece of advice, never make an assertative statement unless you know for sure. Check and do the research first. If you have proof, then be assertive with the statement. If you don't have proof, preface it with some information that indicates you are not absolutely certain. That way it makes it clear to the reader whether you are asserting it as a fact or an opinion. You could not have had any fact that I was speaking to others regarding the information in my post because there was absolutely noone I was speaking with. I beleive you assumed I was younger than I am, and thus did not believe that I would have the experiences I shared, but your assumtion was wrong. I am not posting this to belittle you, but just to caution you on future selection of your words. Be honest with the reader as to what you have facts to prove and what you beleive, and then the information that you share will be credible. If you assert something as fact that is untrue, though, you will lose credibilty. I do not recall any previous posts by you that make me question your credibilty, so I assume the statement above was just off the cuff. We are all guilty of making such statements. So it happens. But I often put alot of time and thought behind my posts, and it is offensive to me for someone to make a post dismissing my work as the work of someone else.

streetzlegend

iTrader: (2)

Well the AFR being in the 9's was before having this issue. I then corrected that, and then raised the boost, ever since then AFR's have been between mid 10s and mid 11's, depending on what boost I had it at. Right now is at mid 11's.

I guess I had fouled the plugs during those times it went into the 9s (although by my visual inspection they dont seem too bad).

For the emanage, yea there are multiple maps you can run and change them from a flip of a switch. Also the injection kicks in at certain boost, in my case at about 10psi it starts spraying. I have been doing alot of reading on spark plugs, I actually have those links bookmarked already lol, they are great. Another guy over at the maxima forum (grey99max) also relies on reading the plugs and has given me a few good sites to study, its amazing how you can even determine how much timing an engine is running based on how the plugs look, his also one of the older guys on the forum.

I have considered the injection safe device, but I dont have my wastegate controlled with a solenoid, its a manual controller. I have however been thinking about getting a J&S Safeguard (its just a lil high in price $543) but its something that will save my $2k invested in building my motor.

ttg35fort

iTrader: (2)

I am not familiar with the J&W Safeguard. You need to CAREFULLY evaluate what it will do for you. IFF (meaning if and onlty if) it will automatically cut your boost when the meth tank runs dry, then it sounds like a good option. If it will not do that, then you should get an electronic boost controller and a suitable controller that will cut your boost when the meth tank runs dry.

streetzlegend

iTrader: (2)

Well the JS has been around for about 10 years or longer i think, its a timing control device. It basically keeps the engine from knocking by retarding the cylinders individually. When it picks up even the slightest hint of knock (non audible knock that only a KS can pick up), it instantly retards timing on that cylinder that just knocked. People have even put the thing to the test by raising the boost to purposely see the limits of the VQ30 and the engine never gave, because the JS kept it from knocking.

I have also thought about setting up an electronic controller as well, I just need to get a better solenoid because the GM solenoid I was using previously was basically maxed out (as far as duty cycle).

I also have my meth in the windshield washer tank, so as soon as its running low on fluid it gives me a nice bright yellow light, iv tested it and when the light turns on, there is alot of meth still left, so its a good indication that tells me i need to refill very soon but dosnt suddenly run dry

MardiGrasMax

iTrader: (8)

The J&S is a good unit. I used it sucessfully on my old Maxima. I think their is a used one for sale on this site now for $350.

ttg35fort

iTrader: (2)

Based on your description of the JS device, it looks good. Have you adjusted everything as necessary to make sure that your AFR never drops below 10?

streetzlegend

iTrader: (2)

Yes I have, I really want the JS but its not cheap. Hopefully the guy that had it for sale still has it. btw mardigrasmax is an example of one of those brave people who pushed the VQ to their limits.

streetzlegend

iTrader: (2)

Thnx mardi, i found a FS thread but was posted in 08. I PMed the guy to see if e still has it.

ttg35fort

iTrader: (2)

It looks like you guys have it under control. Good Job.

I've got work to do, so I'm signing off the forum for a while.

I'll see everyone after the first of the year (unless anything happens with my build between now and then, e.g., getting my short block from GTM).

streetzlegend

iTrader: (2)

Thanx again for your help terry. goodluck with the build

streetzlegend

iTrader: (2)

So I have since put a larger turbo, j&s. And just up the boost again to 17. Afr at high 11s, still spraying meth, however I have been still fighting misfires. Dynoed at 380whp at 10psi with tons of missing. New 350z coils and reduced gap to about .026-.027, still misses. Misses are at mid 4k and around 5.2k always. After that it clears up, then occasional mis at higher rpm.

Timing, I have it in the low teens going up to mid teens like 18 at 6k. you guys think low timing with the and low compression is causing the misses?

str8dum1

iTrader: (11)

fwiw, thats more timing than I run on my kill tune. so, no thats probably not the issue.

does it still miss when not spraying meth?

Chris@FsP

iTrader: (4)

No. You may need to look into upgrading the ignition system.

streetzlegend

iTrader: (2)

@str8 I have not tested without meth yet. You don't think 12 or 11degrees is too low at 4k with meth?

Chris, aren't there guys making high HP on stock ignition and coils? What do you suggest? Boost a spark, msd,.. ?

Chris@FsP

iTrader: (4)

Yes, but on the 350Z ignition system. I don't know how the Maxima ignition compares.