Bad Gas

[Rider90]

I'm gettin' pizzed...

I tried BP/Amoco, Shell, and Mobil and got detonation at WOT from all three. I figured what the heck, remove the programmer and maybe that will detune the car enough so it won't matter. Well it's in stock form, and although I am satisfied I achieved a new best of 21.4 MPG mostly city/some hwy with 4.10s, I am severely disapointed with the gas I've been getting at the pump.

Still detonating at wide open even in stock form. Could it possibly have anything to do with my K&N CAI? I don't see how, but is it possible, should I remove that too? What would you do?

[metroplex]

Short of a tuning/mechanical problem, try Sunoco fuels. When BP/Amoco and Mobil will ping in my Vic, Sunoco has never failed me.

[snowbird]

I'm having kind of the same problem for the cold season.:( It vanish away in april.

IMO, the fuel companys are playing with the octane rating (downrating it) for the winter season so their products are easier to fire on cold start. The downside is that high performance and high compression cars sensitive to cheap crap just react like it was cheap crap and ping. It also might have to do with the denser colder air leaning the mixture, i'm not shure. I would have thought the computer would notice and adjust but it doesn't seems to be always the case.

So either back off the timing with an alternate tune or feather treat the throttle to avoid a costly surprise in the engine department.

[metroplex]

I didn't see you had a K&N CAI. That could be it. Your MAF transfer function is skewed unless you tweaked the transfer function to match the new air intake assembly. Adaptive only does so much in closed loop, but when you go into open loop its slightly different.

Maybe I said it wrong, it's kind of early in the morning :sleepy: and the coffee hasn't kicked in yet.

[FordNut]

I didn't see you had a K&N CAI. That could be it. Your MAF transfer function is skewed unless you tweaked the transfer function to match the new air intake assembly. Adaptive only does so much in closed loop, but when you go into open loop its slightly different.

Maybe I said it wrong, it's kind of early in the morning :sleepy: and the coffee hasn't kicked in yet.
I'd agree with this, it would be a good idea to get a new dyno tune with the setup and gas you're gonna be using.

[Bradley G]

Did someone say Dynotune? :D SCT Marauder software just arrived!

[MitchB]

There is the possibility that you are now running on oxygenated gas. If this is true, than this will lean your A/F several tenths of one point. At WOT, your EEC does not learn and will not compensate for this. I'd like to see you run a slightly richer A/F at high throttle. Also, the oil in your K&N filter might have migrated to your MAF and this too will lean your A/F.

Mitch

[metroplex]

Mobil's gas map shows the Northeast part of IL and Southeast part of WI as using Reformulated Gas (North) with Ethanol. There is a good possibility its the winter blend screwing with your tune. NJ uses Reformulated Gas (North) and I never found any consistency in the gas quality from BP/Amoco, Mobil, or any of the stations except for Sunoco. YMMV though.

[Rider90]

I'll take the K&N off. I don't have any gas stations named Sunoco anywhere near me, or atleast that I've seen :(

[04funmerc]

I just put a K&N CAI on a couple weeks ago and have an SCT/Lidio tune.

I use strictly CITGO or SHELL and have had no problems. I just got back from a 1200 mi. trip to northern Mich. for the colors tour and did a few(Lots) of passing on the two lanes, no probs and just loved the new sound at WOT.

Good Luck

JIM

[DEFYANT]

Sounds like winter blend gas.

I use Sunoco with good results. I just came through the NJTPK and filled up on 94. No problems here.

[metroplex]

Sunoco has the market cornered on the NJ TPK and the Ohio Turnpike.
If you have a Chevron station, try the 93 octane. It's supposed to have some Techron in there.

I was coming home from training at Ft Dix and hadn't eaten anything and stopped by a Turnpike rest stop for food. BIG MISTAKE. HOLY SCHITT, $7 for a McDonald's cheeseburger combo meal?????
I also agree about cleaning the MAF sensor wires - the K&N oil could have contaminated it. Just clean it with electric contact cleaner (this isn't the 6-wire harness, its the sampling wires inside the MAF sampling tube).

[Ross]

I can't believe that no one has jumped on a thread titled "Bad Gas." :banned:

[wchain]

Clean your MAF

[SilverStreak]

I thought they were suspending all the " 73 special blends" stuff in the aftermath of Katrina. I hoped that would include the crappy winter gas we have in the Chicago area too.:dunno:

[Zack]

Jason, what kind of programmer do you have?
If you come by this weekend, I can tweak your program for you.
Free of course.

[Rider90]

Jason, what kind of programmer do you have?
If you come by this weekend, I can tweak your program for you.
Free of course.
Diablosport. But I uninstalled it a little while ago, and even on the stock timing I still get detonation @ WOT. I had zero problems with the gas a little over a month ago, now it all went down the drain. When I have the time, hopefully this week, I will uninstall my K&N and put the stock airbox on. While I am at it, I will also clean the MAF. I think I still have some contact spray left over from the Vic, but radio shack is down the street anyways. I will bump this thread once those things get taken care of. Zack I may take you up on the offer some day, but right now I just seem to have some bad fuel or a MAF that needs attention.

If anyone else has ideas, please post them. I also have an intake spacer.

Charlie - I also have not seen a Chevron around here. Shell, Amoco/BP, Mobil, Clark, Marathon, Citgo is all that I can think of off the top of my head.

[Rider90]

Did someone say Dynotune? :D SCT Marauder software just arrived!
How about that price bee-rad?? PM me back

[metroplex]

In that case, clean your MAF first before doing anything else. it should not be detonating on the factory tune!

[mpearce]

Short of a tuning/mechanical problem, try Sunoco fuels. When BP/Amoco and Mobil will ping in my Vic, Sunoco has never failed me.
Rider90...you'll get varying opinions on this all day long...here's my 2c.

The opposite is true for me. I have a tune for 93 octane, and refuse to put anything other than BP 93 in the car. I've never had a problem...ever...even when out of state. Sunoco however is a completely different story. Their cas (around here at least) is total crap. Plus...they also sometimes switch to a "winter blend" which is even worse.

-Mat

[metroplex]

Rider90...you'll get varying opinions on this all day long...here's my 2c.

The opposite is true for me. I have a tune for 93 octane, and refuse to put anything other than BP 93 in the car. I've never had a problem...ever...even when out of state. Sunoco however is a completely different story. Their cas (around here at least) is total crap. Plus...they also sometimes switch to a "winter blend" which is even worse.

-Mat

BP 93 is the worst quality gas you can get in Northern NJ and SE MI. It's hardly consistent enough to be called 93 octane. It will ping badly one week, and will run fine on another week. Like Mat said, you will get varying opinions on this.
There's no winter blend in SE MI which is kind of neat.

[TechHeavy]

BP 93 is the worst quality gas you can get in Northern NJ and SE MI. It's hardly consistent enough to be called 93 octane. It will ping badly one week, and will run fine on another week. Like Mat said, you will get varying opinions on this.
There's no winter blend in SE MI which is kind of neat.I use Sunoco exclusively with great results. My local station even sells the 100 octane race fuel. But the reason I like Sunoco the most is that their fuel comes from U.S. refineries ONLY. They do not import oil from the Middle East.

I'm sold! :)

But Rider, it does sound like you need a good dyno tune. :2thumbs:

[metroplex]

I read Sunoco does get most of its oil from Venezuela? and not the middle east.

My local station has turbo blue 105? or was it 115? octane gas. I know they have an unleaded race fuel and a leaded race fuel. There's a warning sticker that says its for racing only (NASCAR, NHRA, etc...) and may contain lead which can destroy catalytic converters. $5/gal. :eek:

they are also the only station to have 87, 89, 93, and 94 at the same pump in NJ, OH, and MI. Everyone else is either maxed out at 93, or (gulp) even 91 octane.

[TechHeavy]

I read Sunoco does get most of its oil from Venezuela? and not the middle east.

My local station has turbo blue 105? or was it 115? octane gas. I know they have an unleaded race fuel and a leaded race fuel. There's a warning sticker that says its for racing only (NASCAR, NHRA, etc...) and may contain lead which can destroy catalytic converters. $5/gal. :eek:

they are also the only station to have 87, 89, 93, and 94 at the same pump in NJ, OH, and MI. Everyone else is either maxed out at 93, or (gulp) even 91 octane.
You could be right Metro. The article I read wasn't clear and was a while back, but I distinctly remember it reading that the oil was not from the Middle East. The article's main point was that if we didn't buy gas from Texaco, Shell and other major gas suppliers that DO import from the Middle East, (even for just one day); we could hurt them and make them consider the rising gas prices.
BTW, I was told not to put that that higher octane leaded fuel in my MM.

[metroplex]

Yep, you read right: Don't use the leaded gas! Lead and our cats do not mix well together! :help:

[grampaws]

DITTO! Leaded fuel will plug up the catalytic convertors...
Absolutely no lead..for racing vehicles only...or older cars
without cats...

Yep, you read right: Don't use the leaded gas! Lead and our cats do not mix well together! :help:

[watts428]

OK, try some Maalox!!:D

[Rider90]

1) Used the Motorvac service on the engine
2) Installed factory airbox, tube, and filter
3) Cleaned MAF with electrical contact spray
4) Keep in mind this is the FACTORY tune I've been detonating on
5) Cleaned throttle body

Over the next couple of weeks I'll be doing some testing with fuels, this thread shall be bumped.

[Rider90]

Tank is 100 miles on BP/Amoco Fuel and no detonation on stock tuning/stock airbox. With the Diablosport Predator reinstalled, also, no detonation at WOT :beer:

For those just tuning in I was getting detonation at WOT with the Predator installed. Waited a few tanks of different brands, still detonating. So I uninstalled the predator, still got detonation on stock tuning with BP/Amoco, Mobil, and Shell fuel. Did the following, each may/may not be related to the detonation:

1) Used the Motorvac service on the engine
2) Installed factory airbox, tube, and filter
3) Cleaned MAF with electrical contact spray
5) Cleaned throttle body

And voila, all is well again. Thanks goes to all of whom contributed to this thread. NEXT! Researching the oil seperator subject...

[Marauder386]

Sort of a hijack... I used to run RoadPig 1 ( daily driver ) exclusively on Citgo.
Started to get "random firings " across most of the cylinders. Changed out plugs for new, switched over to BP/Amoco and all was good. Now this problem has returned. When in motion and have reached about 45 to 48 mph, you fell random lurches... I am at a loss now...
The old plugs have a red deposit on the electrodes ( red like firetruck red ) and you can rub it off and it feels sortof "plastic" ... Thoughts and armchair quarterbacking graciously accepted ...

:cool: