AZ Power & Sound

iTrader: (2)

Ok, the car is a 01 SS M6, G5X2, Shaner S3, true duals, headers,misc bolt ons, stock fuel and custom tuning by LG... I origionally had the 85mm MAF on there as well, but I just put the stocker back on to see if it helped. Anyways cat has a BAD detonation problem at low rpms, and also TERRIBLE at 3rd gear higher rpms, I mean like consistent off the wall detonation. When I spray it literally almost slows the car down from so much detonation. On Autotap the car has LTrims pinned at 25 and they wont come off unless I let off the throttle, then they drop on decel. I stuck the car on a wideband and the a/f was a consistent 17-18:1 below 3000 rpm, then above went to 10:1. With a MAF Translator at 20% more base and 14% less WOT the best I could get was 16:1 a/f at low RPMs, then flattened out to a 12.5:1 high rpm. I checked fuel pressure and it is at a consistent 61 PSI (adjustable regulator) and doesnt move when I go to WOT. Ive tried a stock MAF and the 85mm so that isnt it. the car is in AZ where its about 110 degrees out usually and the best fuel we have here is 91 octane. Car never sees over 195 degrees and has not had a pinging problem until the cam and tuning went in, but at the same time I also did the 85mm MAF and Shaner S3.

Can anyone suggest what the problem might be? In addition (might be the mechanics fault, might not) but there is a spare vacuum line that he just plugged. It came off the "Y" from the back on the manifold and it is one of the two tiny lines. I wasnt sure if maybe that went to a regulator or some other part?

Dope

iTrader: (2)

Just a few thoughts. You're wacky lean at lower rpms as noted by your crazy high LTRIMS (maxxed out) and crazy high AF ratio on the dyno. But fine at high rpm/WOT. One thing that comes to mind is that O2 sensors are taken into account at part throttle but not at WOT - try replacing them. If that doesn't do anything, put your stock TB back in. Doesn't seem to make sense but there might be something wrong with it (vacuum leak at low rpms that seals at higher rpms or something?) I would also check up on LG's tuning. They could have screwed something up - maybe by accident. Even a stock tune should do MUCH better than what you're currently doing. The stock fuel system should be fine at lower rpms, so I don't think you're exceeding it's limits and causing it to lean out. If it was at high RPMs that would be a different story.

I don't think the problem is with octane or heat given all the things you noted. I don't know how car-saavy you are, but your ltrims and AF ratio readings indicate a lean condition and that is it. Heat problems cause detonation but not lean conditions, same with low octane gas. Lean just means you're not getting enough gas to go with the amount of air you're getting in.

I would also not drive the car (unless to test) till you fix the problem. And don't freakin spray it! Gah! I can't believe you still have a motor after you sprayed with a 17-18:1 AF! WHEW. Do it again and you'll be picking up pieces of your bottom end off the road.

Just some thoughts that jumped out at me. Any SES light too btw?

Dope

Smoke_Ford

My suggestion is to have the injectors cleaned. The thing about the TB is that the computer should learn the specs, and it should only idle like garabage for the first 2 mins or so. But Dope is right, you are running lean. Be careful, too lean and you can burn a valve.

AZ Power & Sound

iTrader: (2)

engine does run a bit warm lately... no SES lights either. There was for a while and the code was the LTrim 25 all the time code, not sure what the scientific name was, but that one came up a few times. I cant swap TBs cause my old one went to shaner, I swapped MAFs and it didnt really change anything. The weird thing is 1st gear is fine, 2nd is 50/50, but 3rd pings like CRAZY.

Dope

iTrader: (2)

The code for the LTrims is the 'too lean' code, heh.

Take it to wherever you got it tuned and get it checked out. If your O2s are that bad you'd probably have gotten a slow/no switching code for them already.

If you want to do it yourself, I'd get a spare prom, and get it flashed at a dealership with the stock tune. Swap it in and see how it does. If it's okay, your tune is totally fudged, and you gotta bring it back anyway

Dope

Mike K.

I agree with these guys, get your pcm checked out and don't let it detonate anymore. You are running very lean. I take it your fuel delivery system is ok?

AZ Power & Sound

iTrader: (2)

Everything checked out that I could test... Im pointing at the ECU right now. It was fine before the cam and tune, so has to be lying there somewhere. O2s are almost brand new. It wasnt a lean code, it was some code that the car had to put too much fuel in or something. I dont remember, its on my buddys computer when we ATAP'd it. Im gonna send the ECU back to Lou probably next week for a reflash

AZ Power & Sound

iTrader: (2)

Friend of mine said it could be the intake manifold leaking... could that show these same problems?

AZ Power & Sound

iTrader: (2)

Also, the mechanic that installed it had an extra vacuum line, one of the real small ones, he just plugged it and said it was nothing important. It was one of the lines that came off the "t" behind the manifold

Dope

iTrader: (2)

A vacuum leak would make it run lean, yes, but it would be lean all the time. Unless you have some sort of weird situation where you have a vacuum leak and it seals up at higher rpms. Sounds unlikely though. If you're doing mail-order tuning with LG, I'd point my finger at that. Mail order tuning is a gamble. Either do it yourself, leave it stock, or bring it someplace local. I would never mail order something like that.

Dope

Dope

iTrader: (2)

Also, I have no idea what that vacuum line does, that could be very suspect. I'm sure someone here has done an intake swap and knows what it's for.

Dope

AZ Power & Sound

iTrader: (2)

Ive tried, on all the install articles, they leave that one out... Far as the tuning goes theres no one in AZ that tunes unless you have LS1edit, which I dont have... Im probably gonna tear the manifold off tonight and have a looksee

AZ Power & Sound

iTrader: (2)

found the leak, fixed it and put the stock MAF on... got hte LTrims to normal, however still HEAVY pinging in 3rd and VERY heavy with nitrous... LTrims are normal now though... any suggestions?

Dope

iTrader: (2)

You're STILL spraying it?

What was leaking? If it's only improved somewhat, maybe you still have a leak? What are your O2s at WOT?

I'm in the same boat, there's no tuners here in MA. So I bought LS1edit and did it myself.

Dope

AZ Power & Sound

iTrader: (2)

I just spray breifly to hear if its pinging or not... Update today, took off my adjustable fuel pressure regulator to drop the pressure back to 58 PSI, still the stock MAF, MAF Translator is at 0 base and +8% WOT and it seems to be working decently for now... still feels down on power a bit and I didnt spray today cause it was 110 degrees.

Todd@AZPowerAndSound

iTrader: (1)

Im thinkin you should just sell me your car for 10 geez.

Sorry I cant help ya mikey, wheels are my thing.

ssfiress

my boyfriend needs to stay off this ****. we can't even spend time with each other anymore because you all cant stop worrying about your stupid *** cars. please stop being *****'s about everything and become men. maybe you can actually be good boyfriends and spend quality time with your girlfriends!!!!!!!!

ssfiress

sorry bout that just went out to move my car and i come in to see this dont pay attention

Dope

iTrader: (2)

What the hell?

Louis, you trying to tell us something?

Dope

z28fiend

HA HA! SSFIRESS. SOUNDS JUST LIKE MY "EX." NOTICE THE PARENTHESIS AROUND, "EX!" I NAMED MY CAR AFTER HER AT ONE TIME SO THAT I WOULD'NT HAVE TO CHOOSE BETWEEN THE TWO. WELL, LOOKS LIKE I'VE CHOSEN! HA HA!