etoomey3

Hey Everybody,

I have a '06 Scion tC, in the past couple weeks I've noticed my car running really rough above 5K or so. I checked for codes a week ago and only had a o2 sensor code for running too rich, which is due to my injectors. I had no other codes. Today I checked for codes again and I had a MAF code and a Misfire code. I cleaned the MAF and put new plugs in the car, still had both codes. I replaced the MAF this afternoon and the MAF code went away, and the car runs a little better. I still however have the Misfire codes. I took the plugs out and they look good, The Misfires were on cylinders 1 and 2 so I swapped the coils from cyl 1 and 2 to cyl 3 and 4 and vice versa. I still have Misfire codes on cyl 1 and 2. I did a compression test, and all of the cylinders read consistant at ~160-165. I checked the wires to the coils and the wires are all fine, no chafing, no pinched wires. I am going to do a leak-down test tomorrow, but I doubt it could be the valves, but who knows.

Has anyone else had this problem? Do we have an Ignition Control Module? I'm using NGK V-Power Iridium Spark Plugs and they are properly gapped. Any input is appreciated.

Thank You

sciontc_mich

your first problem is that v-power plugs are NOT iridium! You're using copper based plugs! Go get NGK Part No. 4589 it's called OE Laser Iridium. Then see how it runs. Our engine is designed for Iridium, completely different than copper core, even if copper is available doesn't mean we should use it. Try that and let us know.

http://www.ngksparkplugs.com/part_fi...gineid=1475648

r

etoomey3

Thank You Sir! lol, I realized that when I was looking at the car Saturday, so I went and bought Iridium plugs Sat afternoon, but still no luck unfortunately, still misfiring on Cyl#1 and Cyl#2. I'm thinking it could be my injectors, so I'm going to put the stock injectors in this afternoon and I will keep you posted. Hopefully that's the problem, and I'll just have to buy new injectors. I really hope it's nothing serious

garynkim

most likely is ur injectors..

garynkim

most likely is ur injectors..

sciontc_mich

no problem about the iridium plugs. but yeah i'd replace the injectors and see if that solves it.

why did you take the stock injectors out?

etoomey3

Stock injectors did not help, I took them out and put in 550cc injectors because I am in the process of turboing my car,. The injectors were in the car for about 2 months before this started happening, but switching them out did not help, along with new iridium plugs, and a new Mass Air Flow, which was replaced due to the sensor reading out of range. so I have a new MAF, new plugs, stock injectors, and I am running out of options....

07_Tc_blacksandpearl

Did you try resetting your ecu whenever you put your stock injectors back in? Also, did you do a wet, or a dry compression test? Not to question your ability, but are you sure it was performed correctly? About the only other thing I can think is that you have a coolant passage blocked somewhere around cyl 1-2 or in the head by cyl 1-2, causing preignition in the cylinders. I would try the stock injectors, unhook the battery for like 10 minutes. Put the battery back in and start it. Let the car idle for like 5 minutes before raising the rpm's at all. Let me know what you find.

etoomey3

Yes I disconnected the battery when I replaced the injectors to let the ECM reset. I did a dry compression test, then a wet compression test because one of the cylinders was reading low, but after the wet test it was fine. I'll have to check on the cooling system, I didn't even think about that. and I'll let it idle for a few minutes. Thanks for the input, I'll keep everyone posted.

etoomey3

so........car still giving me trouble starting even with the new battery, the charging system is working, the starter is getting plenty of juice.....I'm at a loss right now, lol, I disconnected the NEW battery for about 20min., then went to start it and it took about 3 tries to get it started, then it idled really rough. I let it idle for a good 10min or so, then went out and it w as still rough, and it still drives rough. I'm going to change the coolant and see if that helps any, maybe there's a bubble in the system causing pre-ignition.

sciontc_mich

maybe this won't help, but I just had a thought about the throttle plate sticking due to deposits. Maybe take a look at that and see if it's dirty.

Im wondering that it might cause the idle to be rough, since it's not opening properly? yeah its a long shot, just trying to help

etoomey3

I thought that too, I had cleaned the throttle body about 2 months or so ago. I'll check it again to make sure it's not dirty. Appreciate the input, I just need a beater so I can take my time w/this car, lol

cburglb34

dude i live in germantown very close to damascus pm me so we can meet up and now that u got it started put the stock injectors in, ur not turbo yet your just causing your car to run really rich with them.....put them in reset ecu let car idle for 10 mins and then drive some itll prob fix it oh yea and def could be maf sensor....


to test is its maf sensor.....unplug the connector for the maf and start car if it runs better than thats the problem....



might be front o2.....unplug that and if it runs better then its that

sciontc_mich

Yeah I'm just tossing out ideas as they come to me.

What about the catalytic converter? If that was plugged or damaged, wouldn't you get misfires as well? Now that is definitely covered under warranty! 80k emissions warranty.

Im wondering if the cat failed, wouldn't it through a code?

Plus, you were running other injectors causing it to run rich, that might have burnt out the catalytic. Might want to check that too.

etoomey3

dude i live in germantown very close to damascus pm me so we can meet up and now that u got it started put the stock injectors in, ur not turbo yet your just causing your car to run really rich with them.....put them in reset ecu let car idle for 10 mins and then drive some itll prob fix it oh yea and def could be maf sensor....


to test is its maf sensor.....unplug the connector for the maf and start car if it runs better than thats the problem....



might be front o2.....unplug that and if it runs better then its that[/quote]

Thanks For The Input, I tried the MAF already and it didn't run any better, I'm going to try disconnecting the o2 sensor and reset the ECU and let it idle for 10min and we'll see what happens, and if I do get to a point where I get stuck and need help I will def. PM you, and I greatly appreciate the offer. I'll keep you guys posted

etoomey3

I reset the ECM, unplugged the o2 sensor and it still had a hard time starting. Ran like Poop, Then drove worse than before. I'm going to look at it at work tomorrow, one of the guys I work with used to be a mechanic, I did too, but he has A LOT more experience than I do, maybe a clear head will help, I'll keep you guys posted hopefully we'll figure something out

N0AuTHoRiTy

iTrader: (3)

Hey all. Although I'm new here, I thought I'd put some input into your situation. Have you tried doing a leak test on your engine? You possibly could have a leaking intake manifold gasket which will also cause a misfire, but then I think it will also throw out a running lean code if I'm correct.

cburglb34

oh yes i forgot ur running lean make sur eu cheak all vaccuum hoses intake couplers...and manifold leaks

etoomey3

Hey Guys, so.......I'm guessing there's a fuel leak......100miles to half of a tank, but I don't smell fuel, or see fuel anywhere. The car doesn't want to start, when it does it idles like poop. I'm thinking it's the Converter. Still have to do a leak test. The car revs to redline in neutral, no factory cutoff at 4500 like normal. 1st gear is fine, pulls hard, 2nd gear is ok, misfires, but falls on it's face around 4500, so I'm going to do a leak test, and if I find nothing I'm going to take my car to Toyota, and have them check and see if it's the converter, it should still be under warranty up to 80K miles, I'll keep you guys posted over the weekend

sciontc_mich

yeah that's what i was saying was that the new fuel injectors caused it to run rich. The computer couldn't change the air/fuel that much and it could've burned out the converter. I would replace everything stock so the dealer cannot give you excuses. The converter is NOT cheap at all!