my 393 started breathing today!

[riceslayer302]

looks like you fixed it for the most part.

hank williams iii ftw

 

[lickem]

ya for the most part she is running pretty good right now, well... let me rephrase that and say i can live with it now, she still has a few issues such as the ticking or tapping i got goin on once she is warmed up, still gotta get a decent cowl, and get a few other things but lemme tell you its running way better then it was. pulls like an absoulte train up to 3500, need to figure out why it seems to give out above that but im pretty much positive ive got it running as good as its gonna run without a tune. i had it in second gear and got in it and she smoked the tires without me dumping the clutch. keep in mind i still have my 2.73 rear end in the car. imagine the 4.10

i dont know if it was either the iac or if it was the major clocking degree of the maf, either way im not that concerned about it cause she is runnin pretty good.

thanks to everyone for helping me out with my troubles. every bit of advice given is better then no advice and im alot smarter and better off from it.

not much better then hank iii in the cd player in a fox body mustang at 80mph on a country road! that cd has been in the cd player in my car for atleast a year and a half, never get tired of it.

ill take her out of the garage tomorrow and take a better all around video of the car, thanks again

 

[Cobra912]

Hehe it must have been clocking the MAF because I wanna take credit for somethin!

Good to hear it's coming together!

 

[FastDriver]

Dumb question, but do you have the spout connector plugged in. When I screw around with the timing, I often forget to plug it back in. If not the computer won't advance the timing and it will fall on its face right around 3500... Just a shot in the dark.

Chris

 

[lickem]

it quite possibly could have been the clocking of the maf, the first time i tried clocking it i didnt do anything drastic because i didnt understand the concept of why clocking it might work, i just went to around 11 oclock, 1 oclock etc. nothing really drastic but i was talkin with fastdriver on the theory behind why clocking the maf can sometimes work and he said it was to get away from the turbulance of all the air being sucked in. so right after that i went back out to the garage and got to lookin at it and the furthest away from where i would think the turbulance would be highest would be closest to the fender so thats where i put it.

i know for sure i put the spout back in it but ill remove and replace it again in the morning to see if it just isnt seated good and see if that helps from it falling on its face. ill also try a few different degree settings and see if that makes any difference as well

as stupid as it sounds im more excited that i finally got the idle under control then anything else. my god it sounds mean idling at 750 with the f-cam. was at a redlight earlier and there was this van next to me and i dunno why but i looked over at him when the light changed and both the driver and passenger both had their jaws dropped so i naturally had to get in it a lil bit

very rewarding once it all comes together and you have the satisfaction of doing it all yourself....well yourself and the help of everyone on stangnet i guess i should say.

 

[FastDriver]

yes i cleaned up my plugs really good and reinstalled. when you stated that could be why i was getting weird o2 readings you are refering to while it was trying to burn all of the oil correct?

No. You'll get weird O2 readings because in one cylinder you've got a rich condition where too much fuel is going in and all of the O2 is burned. The O2 sensor identifies this correctly because it senses a lack of O2 in the exhaust. But, in another cylinder that has a fouled out oil-carbon caked plug, even though too much fuel is injected, the spark doesn't come and no combustion happens. All of the O2 in this cylinder goes out of the exhaust and the O2 senser "sees" it thinking that it's a lean condition. The O2 sensor doesn't realize the true reason it sees the O2. It just knows that there's too much O2 in the exhaust and IDs the problem as a lean condition because in a lean condition all fuel is burned and O2 is left over. So, despite the fact that you actually have a rich condition, the computer is reading lean, which would make the problem even worse. The computer tries increasing injector pulse width to compensate making the problem worse in all of the working cylinders. The computer can't make up its mind because it's sensing lean and rich mixtures. This is one possible reason your computer was throwing both codes.

i cant see why 42's wouldnt work with my combination but with nothing else working i wanted to try something different especially after talking with gary brandt about it.

completely understandable

i dont know if you had the chance to read that link i posted about adaptive strategys and setting fuel pressure but it is pretty good and completely makes since for what is going on with my car. ill post it again.

I read through the articles. I needed a refresher, anyway. I'm no pro tuner. There are a lot of guys here who are far more capable than me.

i wouldnt ever debate the fact that getting a professional tune wouldnt clear up some of my issues if not all of my issues but for what my future plans are i just cant justify spending 500-600 bucks on getting a tune for my current combination only to eventually change to afr heads and then have to spend the 500-600 over again to get the computer retuned to the new combination. i could be completely wrong but it doesnt seem very cost effective going that route.

Have you considered buying a wideband O2 sensor setup and a piggyback chip that you could tune yourself? It would be an extremely steep and difficult learning curve at first, but then you'd only have to spend the money once. You're probably looking at $300-$400 for a wideband and another $500 or so for a Tweecer or something similar.

ive been reading alot about adaptive strategy and how the iac works at different times and the more i read the more i understand how they all play into each other but i still cant pinpoint my exact problem or problems. my understanding on how the fuel pressure works according to the adaptive strategy is that you can lower or raise the fuel pressure as far as you want (within the adaptive strategy limits)and the adaptive strategy will just lengthen or shorten the pulse width of the injectors to reach the afr that it wants for that perticular burn cycle.

Yes, but as mentioned in your article the adaptive strategy has a correction factor range of roughly 25%. If your MAF either 1. not reading the correct amount of air mass or 2. is not correctly calibrated for the injectors you have and the combined total is off by more than the 25% possible correction factor, then adjusting your fuel pressure definitely has the ability to get you back into that range. However, this does not guarantee and would most likely not produce a flat AFR across your RPM band. At least it would help, though.

im at 37psi now and it runs the best it has been but i took that as to mean that i must have too big of an injector and if i stepped down a size on the injector then i would be able to put my fuel pressure back to 39psi where it wants to be to begin with and the adaptive strategy would lengthen the pulsewidths of the 30lb injectors for more fuel instead of lowering the pulsewidths of the 42lb injectors.

If you buy the correct sampling tube and get the fuel pressure back in range, it will work. You're going to be looking at some very nice power later, and I feel you will be pushing the limits of the 30s. I've made 420 rwhp with them, though. A 393 with AFR heads could be looking at significantly more power than that. You may not be done with your combo, either. Putting 30s in may be a band-aid until you can get the motor tuned. I know that I'd rather run the risk of driving rich than lean, though.

i also understand that there are max duty cycle limits of a given injector size but isnt it a better idea to run a set of injectors at say 90% instead of running them at 30%. obviously those are totally inaccurate duty cycle estimates of what i would actually be running, i just threw those numbers out there.

First rule of thumb is to never run an injector over 85% DC, especially for prolonged periods of time. From what I've read/heard injectors run over this rate will fail and begin to function sporadically. Second, don't run the DC so low that the injector driver can't correct for the engine's fuel needs precisely enough. i.e. running a 160lb injector setup with anything other than the best stand-alones and you would be unable to get your car to idle. This is a non-issue for you with 42s, which are not too big to get idling on a 393 with a EEC-based piggyback and a tune. 3rd, smaller injectors that can still safely (at less than .85 DC) do the same job are theoretically better because they have a better spray pattern that will better atomize the A/F mixture. I know this implies that the 30s would be better, but I'd personally rather have the wiggle room to go nitrous later, or move to a more stout combination down the road. Plus, you already have the 42s.

i read somewhere that the larger the throttle body the better chance on getting a smoother steady idle which makes since because at idle the iac is open and providing the engine with air while the butterfly is closed. on that note the iac opening is only so big so its only going to flow so much more additional air. just to get my car to idle i have my idle screw set to where the butterfly is far from being completely closed, so hopefully by stepping up a size on the throttle body that will help cure some of those issues. on the surge idle checklist i read that some guys that have a big cam will open up the divider between the 2 ports in the iac which would allow more air to flow through at idle but with me just having a f-cam i shouldnt be close to having a big enough cam to where i would have to consider that would i, or because it is such a big displacement stroker should i try it?

I don't like modifying parts like that. To me, though I admit to being inexperienced at tuning, modifying parts like that is a band-aid. I don't like permanent band-aids. To each his own though... As I mentioned in my PM to you, there are guys with much more knowledge on this subject around... Where the heck are they?

Chris

edit: I forgot to mention that you might try posting questions in the tuning forums here. You've probably got a better chance of running into the guys I'm talking about.