...with some possible troubleshooting routes...

Well, I am gettin some pretty serious, very rapid misfiring when I get around 6.5-7 grand RPM. Background: I hardly ever drive the Evo, in fact I finally started it up yesterday after a month because I decided to take it to the track for some 1/4 times. My battery had been dead for about a week now, but since I never drive it, I didn't really do much but leave it parked in the garage. Well, yesterday, since I was takin it out, I had to use a booster pack to get it started...okay, no big deal, right? Well, it drives fine toolin around town with no obvious issues, but when I took it down the track the first time, up top it had a very fast misfiring/backfiring. I only ran 12.8, but the car can do 12 flats, ANyway, I didn't have any tools, so I just drove it home, again, no issues drivin around town, got home to try the first thing I could think of, an ignition issue, maybe the plugs..okay..I pull em, no strange thing there, but I decide to put brand new ones in anyway...no change in the way it runs, it still misfires up top. So then, I start thinkin, since the battery was dead for so long, maybe I lost my mp in my XEDE for some odd reason...well, I log into my XEDE and check out the map..it's still there, but I decide to load it up from a backup I had. Still, it misfires up top...when I run it and look at my wideband AFR gauge, it is right where it should be throughout the power band

I'm sorta confused, cuz it ran fine and strong for the previous months before the car was parked...I changed absolutely nothin. Only thing is, the car sat with a dead battery for about a week. I'm pretty decent around an engine so I'm not a cluedart, but even this one kinda baffles me. I have a fair amount of mods to inlcude cams, intercooler, springs/retainers, methanol injection, exhaust, XEDE, wideband AFR...etc. But since it sat for a month, is it possible the methanol settled and went "bad"? Is that even possible or am I jus bein crazy on that one? lol...

Anyway, jus wonderin if anybody can point me in the right dircetion with some places to begin lookin...

Thanks

 

Meth doesn't last that long...shouldn't be using meth in a car that sits for a month. I don't know if that's causing the high rpm sputtering, but it's a very risky thing you're doing.

If the new plugs were gapped properly and still didn't work, then consider swapping in some stock plug wires from another local Evo just to doublecheck the spark.

 

hmmm...I didn't know that about Meth....thanks for the tip on that one, I di just buy a brand new 5 gallon drum. the stuff that's in there now has been sittin in my hazmat locker for quite some tiem and I was trynin to finsih it off before I started usin my new stuff..I might drain it out and put the new stuff in it...I wil have to find somebody out here that might be able to help me trouble shoot. Anybody else out know the shelf life of methanol?

 

yah. i hear meth doesn't last more than 2 months or so. you might have just gotten a bad batch (correct me if I'm wrong please). since you don't drive it much either you might have just had a bad gas batch but since your afr's were were they needed to be i'd assume not.

do you have a knock sensor? it will tell you if that meth is bad. best thing to do is just go ahead and toss that meth and get back to us.

about what warr said about the high rpm sputtering. it could very well be that if that meth is bad and you're boosting really high still, your engine might be knocking like crazy, retarding its timing or detonating or something. be very careful.

good luck bro

 

hmmm, interesting...you might be right. If methanol does have a shelf life, then that might be it...I had topped of my resevior with some old stuff that I had in the locker and that stuff was in there for about 6 months or so...didn't realize it was that dangerous...I will take the old stuff out and let ya'll know...

 

thats good to hear. please do

 

well, jus swapped out the meth and same problem...any suggestions?

Anybody in the Sacramento Area mind hookin up with me to test out these coils/wires? Won't take but 30 minutes to swap em out, run the car an put em back in to see if that is the issue or not.

 

get a compression test done

 

well, I'm not really thinkin that compression will have much effect on an ignition issue, but I went a checked it anyway just to see....here are the values from lef tot right while looking at the engine comparment

155psi 160psi 165psi 165psi

not too bad, pretty normal and all within range of each other...

hmm...I'm starting ot lean towards a coil/wire issue...

 

a friend of mine was having some problems like this also with his srt4, the plugs were causeing some of the problem, then he also replaced his vacuum lines. i would say try that because it remedied his misfireing and what not

 

Friend in Indy had the same problem . . . . took him forever to figure it out . . . . .solution = new wires!! SmokedMustang is his name on here.

 

man..I might just go big and upgrade my ignition system..been thinkin bout that Buschur COP setup with the CDi box...i think it's goin for about $1K...man...last I checked a few months ago it was a bit cheaper....

Anybody know where I can get some cheap OEM wires from online? I'd like to try that before i go big...just to make sure...

 

bump. couldn't tell you man =\

whats the update on your car? any good news?