Misfire ... at wits end

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Been fighting with this problem for the last few months and I’m just out of ideas. Here’s the setup, did a full 6bolt swap, 6bolt head, intake manifold, TB, CAS, ect. When I fist put it back together it ran great then after a few days (about 10 miles) it developed some hesitation which then got worse to the point it wont drive at over 10% throttle. Give it any gas and it pops and misfires horribly. If you give it only a little gas you can take it all the way to red line with out any problem. I’ve been checking the plugs every time I run it and if I just leave it idle in my driveway the plugs come out just perfect. But if I drive it up and down the driveway (I have a long very steep driveway) the plug on the #2 cyl comes out black and the rest of the plugs come out lean. I’ve checked the injectors and they seem fine just listening to them. I have also replaced my coil pack. I swap the plugs between cylinders every time I check them and I have run two different sets of plug wires with no effect.

Any ideas or thoughts are greatly appreciated

 

[TSG59_Steve]

Which CAS do you have? You might need DSMlink or the Pot mod.

Edit: Did you swap the wires around?

 

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I'm using the 1g, green top, long tail, CAS. I have the plug wires swapped. I have swapped the plugs wires back then swapped the inputs to the coil packs to double check that it wasn't just one coil pack with with an issue even though i have tried two different coil packs.

I don't know if its the notorious random misfire problem so i'm not sure if dsmlink or the pot mod would work.

please correct me if i wrong because im working off what i think i know at this point,and i have hit my head a few too many times, but the random misfire is a minor problem that comes up after the engine has warmed up and is more or less a check engine light that gets turned on because the Cam-AS is simulating the signal previously given by the Crank-AS. I believe that the problem comes up as a result of the Cam-AS being hyper sensitive vs the previous Crank driven signal... if that is correct, and i could very well be wrong, their is no actual misfire problem or if their is it is a minor one...

what i am dealing with is a severe misfire in one cyl that happens any time i give it any gas regardless of weather the car has properly warmed up or not...

again i am working from memory here and mine has often proven, um well unreliable.. to say the least. so correct me if i have mis-remembered somthing

 

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I woke up to a half inch of water in the passenger side of the car this morning had to take the seat, carpet and sound deadening out to keep it all from being ruined.

Does any one have any ideas on what to test for to see if I'm getting a good signal to the coil pack and to see if im then getting spark to the cylinder.

This problem is kinda familiar to me but in a different context. i had similar symptoms coming from a rx7 that i used to have, they have two plugs per rotor one as a primary one as a secondary. when the engine is under load or you got above 3200 rpm the secondary plug was supposed to come on to help handle the extra fuel but i had a problem with my computer so it would just fall on its face and start shooting flames out the back.

this feels like the same problem... only without flames and with pistons not rotors.

oh well story times over... if any one has any ideas it would greatly appreciate them because I'm serious about to give up on this Damn car before i even get to drive the ####in thing...

 

[ClipseFiend]

, man I just developed the same problem. Only difference is mine is # 3 cylinder. I get the backfire, the hesitation under acceleration, and lack of power. It cranks just fine, but when I try to go forward, it wants to die out. I also replaced the coil pack, plugs, wires, and didnt fix the problem. I keep getting a CEL code but ive been told the code was a dead Coil Pack, and that the B-Side (# 2 and 3 plugs) arent getting proper ground. However, I checked all the plugs and the coil pack and everything is fine. If someone could PLEASE help us both, maybe what is wrong with his is wrong with mine...

 

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Wow. Bringing it back from the dead.

Mine problem ended up being that my timing belt had jumped a tooth and threw everything off by a good amount.


I am a few years wiser than when i posted this up so maybe I can help you. What have you done recently and when did the problem first start.

 

[ClipseFiend]

I havent done anything to it other than basic things. I only bought the car back this last halloween and and has given me nothing but trouble. I will check timing belt and see if it jumped also, which is most likely. Thank you, if this works, youll be a lifesaver. saving the life of one more DSM from the crusher.

 

[DaisyTuner]

ignition coils gone bad? having similar problems, if youre misfiring in 2 and 3 thats def ignition coil. take to a local mechanic who will check that.

 

[GRAVEDIGGER]

ignition coils gone bad? having similar problems, if youre misfiring in 2 and 3 thats def ignition coil. take to a local mechanic who will check that.

Could be, but not definitely an ignition coil. There are quite a few other possibilities.

 

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I havent done anything to it other than basic things. I only bought the car back this last halloween and and has given me nothing but trouble. I will check timing belt and see if it jumped also, which is most likely. Thank you, if this works, youll be a lifesaver. saving the life of one more DSM from the crusher.

Did it run when you bought it? is this a new problem or did it start after some other thing you fixed...

do you own a timing light?

 

[ClipseFiend]

ignition coils gone bad? having similar problems, if youre misfiring in 2 and 3 thats def ignition coil. take to a local mechanic who will check that.

ok, maybe I should specify this. I havent done anything performance-wise. However, I did just spend a couple hundred dollars on new plugs, wires, and ignition coil pack. Ive hooked car up to diag scan tool at school, even check injectors by pulling one at a time. Hooked up pressure tester onto fuel rail and checked the fuel pressure. It was a bit high, but within regs for the vehicle. Im going to see if the belt jumped timing, and hopefully thats my problem.

Did it run when you bought it? is this a new problem or did it start after some other thing you fixed...

do you own a timing light?

It didnt run when I bought it, but it just needed a battery, and some tlc to get it running right. It is a new problem, only a couple weeks like this. Wasnt real bad at first, then got worse as I replaced the ignition coil. Im not throwing codes until im driving down the road. No I do not own a timing light personally, but I know people who do, and I will get them to help me in the morning.

 

[Metalpunk68]

Also Try Your Cam And Crank Sensors

 

[brandon1239]

Check the ecu. I had the same problem and it was my ecu.

 

[BlackMount]

Check the ecu. I had the same problem and it was my ecu.

Have Similar Problem also

It IS me ECU, and i doubted it until i proved to myself by putting it in another DSM and it having the same issue.

Never Doubt the things that seem the simplest.