Well, not completely stranded. My standard 2003 Evo began symptoms almost immediately after I purchased a tank of cheap gas in Page, AZ four days ago. Prior to then, the engine had always performed perfectly, including during the 2,000 vacation miles driven up to that point. I always use premium, which in this part of the country is 91 octane.

During an episode, the engine sounds like it is running on 3 cylinders. When adding throttle, the noise gets louder and acceleration is almost unnoticeable. Early on, the incidents seemed to be random, and a quick lift of the accelerator cleared the symptom.

Even today, the engine ran as it should for one two-hour period. Following a quick stop without turning off the engine, the symptom became hard. The engine runs fine up to 3000 RPM, and then the symptom occurs. Drop below 3000, it goes away.

Auto characteristics:
Mild (mail order) Dynoflash
No muffler
K & N air filter
ACT heavy-duty clutch
No-name front LSD
MR BOV

I am puzzled by the P300 code (Random/Multiple Cylinder Misfire Detected) because during the incidents, the symptom is very consistent. If it is random and affects multiple cylinders, I would expect variability.

Having read many threads about the P300 code, if I were at home, I would start checking plugs, plug wires and coils (and, ugh, the fuel pump). In this situation, I am concerned about aggravating the problem by messing with things. The availability of parts is nil. However, I am debating about going after it in the morning.

My thanks to AutoZone in this town for reading the code for me!

Anyone who has ideas that may save the last week-and-a-half of our vacation, please send them my way!

Thanks,

Steve

 

Sounds like you got bad gas. Try filling up with premium and add a bottle or two of octane booster to get the entire tank up to par. I've heard of some gas stations, especially those in rural areas having 87 octane in the premium tanks.

 

If he's in Wyoming, he's already gone through a bunch of tanks of gas since page, AZ. I would check the plugs first. perhaps something fouled them. Get a set of plugs from the local store, change them and check your plug wires.

 

rod knock, congrats you spun a bearing.

 

I agree that I've been through enough tanks to rule out current bad gas. I guess next steps are plugs/wires. Unlikely I will be able to find either here.

As for a spun bearing, wouldn't that show up at any RPM?

As unenthused as I am about the idea, I am thinking about opening up the gas tank and inspecting for garbage. Make any sense? Of course, I forgot to load my shop manual on the laptop.

I appreciate the ideas!

Steve

 

if possible get couple gallons of race gas. if your tuned bad gas will make it sputter and throw codes alot easier and i have gone through 4 back to back bad gas (tanks)

could be your Spark plugs are fouled and also need replacing. i would try the race gas then check your plugs and then move on from there.

 

Do you have any type of aftermarket ignition system? I had a HSK twin power unit and it failed on me, which made half of my engine turn off... My car sounded like a go cart... it was horrible. I thought it was a bad tank of gas first too, then plugs... i changed the plugs but it did not help, and i was about to do the coil packs ($100/each) but i decided to let AMS figure it out and they did for me for free... they just unplugged and re routed my ignition system to stock and all is MUCH better...

TJ

 

A spun rod bearing sounds like the radiator fan is hitting something,only at certain RPM's.

 

check DV or BOV to make sure it recirculating....yea i messed around with mine for a few days....lol...don't ask it was a ricer moment!

 

I had a girlfriend out that way so I was in Wyoming often. Once I filled up in western Nebraska I'd get the P0300 code. So I blamed the gas for awhile. Then I messed with the ignition. No joy. So I started carrying a scanner so I could erase the code any time it hit. Stopping along I-80 every fifty miles gets old. Finally, I bought a Creader and now I never get the code.

By the way, you can drive the car with a P0300 code. Mitsu offers this advice in place of an actual fix.

 

"Race Gas" will not clean out garbage in the tank. If you have less than a gallon of 89 fuel in your car, filling it up with premium will raise the octane enough that it's not even a concern. If it was crap in your fuel pump strainer, you would have difficulty starting if you put the key in immediately and started cranking... If your engine is fine at idle, but then starts to cut as boost/RPM increase, it's ignition.

Check the plugs... it's a 10 min check before you go doing something more drastic. I can see it now "Crap, I dropped one of the pump cover bolts in the tank"

 

my thoughts exactly when i read his post.

i'm not sure where in WY you are, but if you're close to Cheyanne give JustDSM a pm. i'm sure he could figure it out and would be a whole lot cheaper than going to a stealership.

 

Thank you for sharing your experiences to help me solve this problem.

Here are my reactions to the advice that has come in since my last reply:

I will inquire about race gas. But, I have run the tank down to a gallon or two since this whole thing started. Also, I have been buying at different name brand stations, so I think it is unlikely that I have gotten several sub-par fillups in a row. The octane should be up to pretty close to 91.

The ignition is stock.

The noise is not mechanical in nature. You can hear individual firing strokes, which is a sound not present when the engine runs normally. The term that comes to mind is “motorboating”.

EVOIXMR8916, could you expand?

I have been driving with the P0300 code & check engine light on for some time. I forgot to bring my code scanner on the trip and know that you can drive the car with the light on.

Since we are headed north, Cheyenne would be quite a detour (Evanston is in the SW corner of the state), so if worst come to worst, I will probably try to find a shop in the Salt Lake City area and limp back there. If anybody knows of a shop; especially one that will work on Saturday…

From all of your advice, it seems that pulling the plugs is the first thing to do. I’m going to try to find an iridium plug source in town, go there, pull the plugs and replace them if necessary, otherwise clean and gap the old ones.

I will let you know how this comes out. In the meantime, please keep the ideas coming!

Thanks,

Steve

 

My car does the same exact symptoms about once a month (2000 +/- miles). I don't have any solutions, unfortunately, but the conditions are the same.

Around 3k-3500 rpm, usually in 4th, it does it. I let off the accelerator, and it goes away and doesn't come back for a while. It only lasts maybe 2 seconds, but there's no power and a somewhat scary noise.

I changed my plugs, looked at wires, etc. My car still does it. I now just ignore it and erase the code.

 

Well, Steve you can go back to Salt Lake City, wait around till Monday, have the dealer set your flash back to stock and you will still get the P0300 code. Unless you have an ignition problem where the spark breaks down at WOT you can mess with plugs and wires and you will still get the code. As you know, you can buy fuel from different outlets and still get the code.

What happens as you drive long distances is that the oil in the transmission heats up and thins out causing more vibration to be transmitted to the engine.

One partial solution is to buy a code scanner and just erase the code each time it hits.

Back when I started having this problem I was reading on one of the vendor sites and they wrote that for a particular mod they sold which caused codes you would also need a Creader because they claimed that it would not only read and erase codes automatically as advertised but prevent codes from being set if left in the port. In the off chance that this would work I ordered one.

Once the Creader was in the port on my ECU the code hit once and was erased in a couple of seconds. This is what a Creader claims to do. Well, the code has never been back.