BoostedDSM

iTrader: (6)

So took the car to the track, had about 4 gal of 110 leaded race gas in it with the rest 93. The car sat for a year so I ran some race gas in to help clean it out so to speak. When we left the track I had to put some gas in, the bp only had 87 and was out of 93 and 89.... right after that I started to notice it missing at about 2k to 2200 on the highway around 10 miles on down the road.

So I pulled the plugs out today of cyl 1 and 2 and this is what 2 looks like. I swapped them around and can't get to the others right now without a wrench, stupid headers....


I'm going to put a new set of plugs back in along with a full tank of 89, premium being over 4 a gallon is just stupid. I had TR55's should I run the TR6 or no? also they are gaped at .045. Also not entirely sure what would cause such a buildup on that plug and all that.

F0x Slaughter

O.o what is your car tuned for?
89 or what?
Factory cars are suppose to use Premium anyways.

You do know what octane of gas if for correct?
Then why in the hell would you run racing gas in it then go run 91+.
Obviously the car isn't tuned for race gas so its simply a waste.

BoostedDSM

iTrader: (6)

It had old gas in it from last year, so it was just to clean the system out. Before hand I always ran 87 in it, now with mods and this motor I will be running at least 89. From what I've read so far you only need to run octane just above the detonation level anything more is a waste. I see why running race gas was a waste, I had to do some reading to get a better understanding of it as I had no real idea before.

My main concern is why the car fouled a plug, and is only getting about 10mpg while cruising on the highway. I should note the car does not have a tune that I know of, but the speedo is dead on for having 3:73 gears.

30696bird

iTrader: (4)

My guess is the lead in the "leaded race gas" killed the O2's.

BoostedDSM

iTrader: (6)

o2's were clean when they went back in and made my own extensions. I know I have CEL on but at idle under load it goes away and comes back as soon as the rpm's come up. I have another set of o2's I could put in, but they are black on the tips....

I did however find a plug wire sitting on a header tube earlier, I popped the wire off it's not burnt up just re routed it and took it for a drive it seems ok. Have not cruised it yet to see if the miss comes back.

F0x Slaughter

Doesn't matter if the tips are black. Carbon is going to build up on the tips and make them black, fact of life.

But yes most o2s are not rated for lead.

Also for storing the car just put in Stalbil, done, no need to "clean" anything.

BoostedDSM

iTrader: (6)

Well it was not exactly stored, it blew up last year on almost a full tank of fuel. No more race gas for it though, just pump.

Would the whole not having AIR/EGR and race headers cause a low mpg issue without a tune? I got rid of all of it, even the evap.

That's the first time those o2's have seen lead so I would hope after just that little bit they are not dead. I'll end up replacing them and adding plug in extensions instead of having to make my own too.

BoostedDSM

iTrader: (6)

Still has a misfire, being told to swap injectors out and that will fix it. Seems odd to me Would the car running rich from no tune cause it to foul plugs like that? I'm kinda stuck with not being able to get to the other plugs right now. All my tools are at my other house about 100 miles away.

FSTFBDY

iTrader: (1)

Its all "guess work" over the internet.
Pick up a cheap obd scann tool to look at o2 readings , etc..
Bad opti , plugs , wire are all things to cause a misfire.

Stock tune and getting only 10mpg that thing has to be running pig rich.

BoostedDSM

iTrader: (6)

I can smell it running rich too, I may call in a favor from a friend if he can scan the car with his laptop. He did his own tune, so he should have all the cables still. I know I need to pull DTC's just to be sure it's not an o2 code or what not. I'll start with re routing wires and a new set of plugs and see what happens.

I appreciate any the feedback so far though.

NewOrleansLT1

Sounds like your o2s unplugg them and see if it runs better. Also you can get away with running 87 because you have a EFI vehicle. But your losing power because the PCM is retarding your timing to keep it from detention

BoostedDSM

iTrader: (6)

Unplugging them will put it in limp mode though won't it? Or make it run rich still as it has no way of telling it's AFR?

NewOrleansLT1

Well the car is already rich so if you unplugg them and nothing changes you might need some o2s

BoostedDSM

iTrader: (6)

Good point, I'll try that when i head back home with it. That probably won't fix the misfire but we will see.

great421

iTrader: (1)

Leaded Gas and O2 Sensors do not mix.

The lead in the fuel coats and then chemically inhibits the precious metals (Platinum and Palladium) on the inside of the sensor from doing its job.

(It's the same reason for Catalytic Converters and Leaded fuels.)

If you can acquire a scan tool that can read your pre and post-cat O2 Sensors, look at the readings - The pre-cats should vary in their voltage reading and the post-cats should be much more stable - if the pre-cats do not vary in output, then you've found your issue.

IMHO - Change ALL of your O2 Sensors AFTER the Leaded gas is gone and your mileage will improve.

BoostedDSM

iTrader: (6)

These cars don't have post o2's for 95 If I'm not mistaken, or at least I know mine only has the pre cat o2's. I will see if I can get a hold of a scanner and check them out regardless though. Not having cats won't skew the reading at all would it, can't imagine that would effect voltage at all anyhow.

Bigtoyz

iTrader: (2)

It doesn't take long at all to kill a pair of O2's with leaded fuel. I messed up my Wideband tuning my sled within 10 miles it was shot.

And actually 89 10% ethanol will clean it out. Its the ethanol that cleans systems out that is why old car running reg fuel had issues if sat for awhile and then filled up when 10% came along. It cleans rust, varnish, etc.....

I would also change the fuel filter out also.

BoostedDSM

iTrader: (6)

^ fuel filter was on the list, as it had a little race gas left in it from last year as well. Once I get some of my spare parts sold I'm picking up an ALDU1 cable to datalog the car and sending my spare pcm to pcm4less for a tune. Plus putting new o2's, plugs, o2 extensions in.

Needless to say after doing more reading and understanding octane and all that I won't be running anymore racegas until it's got the boosted 383 setup in it.

BoostedDSM

iTrader: (6)

Just figured I would update this, I reset the pcm by unhooking the battery for a few mins. Drove the car 90 plus miles back home, it still had the miss at random times on the highway, but after pulling the plugs today they are all clean and burning great. I think it could have been a loose boot, but have not drive it enough to see if the miss is gone yet. Scanning for codes in the morning to see what all it's throwing, also have texas speed o2 extensions on order to replace my home made ones.

BoostedDSM

iTrader: (6)

I have 4 codes, 26, 27, 29, and 63. Only one that should matter is 63 which is for bank 2 oxygen sensor circuit open. I'll have a new o2 and extension in it tomorrow or thursday and report back if that fixes my misfire.