allmotor_2000

I don't want to go through an arduous debug on this, so please lend any ideas from experience.

I get misfires (all cylinders) when I start up the car in the morning. At first I thought it was a batch of bad gas, but after three tanks, it is still persistent. I swapped out all the plugs for some IK20's and it still does it when the engine is cold. If I clear the code after she warms up, it doesn't come up. I noticed some crud on one of the plugs (front middle cylinder), so I am unsure if that coil-pack has started acting up. I have also heard about catalytic convertor problems results in these symptoms. Can one coil-pack cause mis-fired on all cylinders? I don't think so, but then again one never knows!?

mrsteve

iTrader: (1)

Just based on what I've read here I think you are in the right direction with the coil packs and/or the cat. I remember reading that a faulty coil pack caused multiple misfires and and very rough idle in one car. Also, I believe "typer" had a bad cat which caused misfires.

CleanCL

iTrader: (4)

coil pack and cat. i think you would throw a code for your cat if that was it. i reaplced all 6 of my coil packs so i have my 6 stock ones sitting here. i haven't figured out how to test them but if you can tell me a way, i can send you one of my good packs so you can troubleshoot the packs.

typeR

Egr?

allmotor_2000

Good point on the EGR, let me remove it and take a look to see
if its clogged up or something!

Allout

Any update on the cause?

allmotor_2000

Nope, I changed the plugs, reset the ECU and checked for opens/shorts on the
harness. No change - the HELMs just asks to replace stuff and I am not going to just do that.

allmotor_2000

I think I know the problem. Front middle cylinder is gone... plug is already fouled and there
is oil in there - a lot of blow-by. Probably need a new block.

ed231

I have been having a problem with my '03 CL-S 6MT and I was wondering what exactly a misfire would feel like? Reason I ask is b/c I have been thinking this might be something related to the exhaust. The problems I am experiencing is first, everyday when I turn on the car and start driving to work my engine will all of a sudden pull back for a second as the engine reaches its normal operating temp, almost like I let my foot off the gas and put it back on. It does it pretty consistently and it will do it in any gear. The next problem I have noticed was during rush hour the other day but have experienced it before. As I accelerate and rev up my engine it sounds a lot deeper, but not in a good way. Almost like it is hollow or not all there. It is a little rougher too, it does this in neutral and rev the engine as well. My first reaction was something was caught in the exhaust, but I don't know. I also noticed it will do it more if I don't give it enough gas when I start in 1st and it stutters a little. Any suggestions?

ghost_masterCL

do you think boosting was the cause of this allmotor?

mrsteve

iTrader: (1)

ThinJim

iTrader: (3)

Very sorry to hear of this Ram. What did the leakdown show? A leakdown can tell you if it's piston/cylnder related or valve related, I'm sure you know that though. If it's a piston, which is my guess, you can change that without pulling the motor. Off with the front head, and pan, and undo the rod and push it out the top. Done this a couple times as a quick fix on some motors before and have seen it done numerous times in various shops.

The cause?.. I'm only speculating, but my first guess would be detonation from the boosting. You'd be surprised at how much this thing detonates unless you have a knock detector that lights up when it senses knock. On mine, I didn't think I was det. , but after putting on the knock detector, it lite up like a christmas tree, it wasnt' sever, but it was always there till I pulled more timing and started running av gas more in the mix of fuel I was using. It doesn't have to be severe detonation to do damage. An accumulation of lite det adds up to a heavy hammer pounding the pistons over time.

Hope you can work this out. Keep us posted.

allmotor_2000

I'll do a compression test and a leakdown - but I can tell by looking at brand new plugs after 1 week

I could get away with just replacing one piston but if I am going through the trouble, its easier to just replace the block with a new (or rebuilt) assembly. Let me ponder it for a while. I have a few months before I start school and the car needs to run properly for the next three years.

On the detonation - you are probably correct. I went by audible detonation and signs off the plug and even a slight amount accumulated over 20K hard miles probably did me in. I mostly used 91-octane as well... at 6psi.

Will keep you folks posted - I was considering selling it, but can't do so given the condition.

allmotor_2000

Is that a rhetorical question?

allmotor_2000

The only other alternative is (and I am contemplating this but not sure if I want to do it) to build a high output 3.7L NA and try to push 350+ whp naturally aspirated. It can be done but might just take too long

ghost_masterCL

oops, forgot the red text :P

mrsteve

iTrader: (1)

hehehe I suppose that too is possible. Already have plans lined up for the valvetrain? Would you use the '05 RL cams?

A brand new complete assembled block is about $1,400 from online Acura parts dealers.

CleanCL

iTrader: (4)

i was thinking about an overbore and resleeving, but i decided against it. i don't want to touch an already perfect block. albeit, 3.7 would be nice. you could probably make up the extra .2 with minimal work, i'm sure the block could take it.

if you have the ability, do it. i just didn't want to be bothered with custom rods/pistons, among other things. i will have spare CL-S rods/pistons shortly, i'd be more than happy to send you a set.

Allout

Sorry to hear that. I was hoping you had a plugged CAT or something easy.

ThinJim

iTrader: (3)

Now your talking. It would be a rather simple undertaking to do and using the RL cams and some head work, 350 could be possible, I'd think closer to 320 though.

allmotor_2000

I have not completely ruled that out, but a cat is a $1100 exercise!

CleanCL

iTrader: (4)

just pickup a magnaflow universal with center o2 and have them cut ur old cat and weld the enw one. thats what i did, didnt cost more than 150 to do the whole thing.

allmotor_2000

I see - might be a cheap thing to try before doing anything else. One concern I have with the entire cylinder #2 scenario is that why are there always misfires on all cylinders (including random misfires). If its something global causing this, then the catalytic makes more sense.

allmotor_2000

Isn't the warranty on emissions stuff > 50K miles? I have 57K.

Let me talk to Acura first....

allmotor_2000

What part # did you order? They don't have one with a center O2. Also, where did you get sub-$150 pricing?

mrsteve

iTrader: (1)

Warranty on your cat should be 75-100k miles. I believe gov't mandated.

mrsteve

iTrader: (1)

Found it on EPA's site.... The Clean Air Act requires an 8 year 80,000 mile warranty on the cat...

CleanCL

iTrader: (4)

http://www.car-sound.com/catalog/universal/540.aspx
part#: 54055.

hottexhaust has it for $81
http://www.hottexhaust.com/search_re...&btnSearch.y=0

should not cost more than 50 to have it welded in at any muffler shop.

allmotor_2000

Thanks... I did more debugging:

1. Put my OBD2 tool and saw that the short-term fuel trim and long term fuel trim were at -10% and -7.2%.
2. Saw that the O2 (secondary) was also correcting about 10% just as the primary O2.

Now, there is a rich condition, so my thoughts went back to the Front middle cylinder. While the engine was running, I removed each connector to the coils one by one and listened to the engine change is 'pulse'. All cylinders made a pretty consistent *pud* *pud* except for the front-middle where the change was hardly noticeable. To eliminate the coil-pack, I swapped it with another one and the result was the same. This tells me this cylinder has low compression - confirmed; but low enough to cause misfires?

Now, why ALL cylinders show misfires is still a mystery. It is possible that the cat is still somehow in bad shape, but I can't think why...? The misfire is not detected like the knock sensor... it is specific to a cylinder - is it possible the ECU goes mad when it gets a lot of misfires and just lights up all cylinders?

allmotor_2000

I'll try the cat option first and then go from there...

typeR

when my cat went bad i had random miss all

allmotor_2000

When your cat went bad, was something actually broken inside and rattling around? How was the cat found to be bad?

typeR

yes a chunk of the honey combe was broken and there was smaller peices too...i thought i heard rattling but at the time thought it was something else...my symptoms were the car cruise and idled fine but would struggle at WOT to the point you could bearly get it to redline 1st gear..after a leak down,fuel pressure test and another computer,at the suggestion of someone here i had my guy unbolt the CAT and the car just ripped the tires off it again...eureka...and covered underr the 80K warranty on emmissions

CleanCL

iTrader: (4)

reason your cat may be damaged, if your running rich, there is probably extra gas shooting into your exhaust and being burned up in your cat.

1 cylinder misfiring can change firing pattern on all of them. do a leak down on that cylinder. i cant imagine just 1 piston being messed up. in fact, i have heard of very few people blowing this motor.

allmotor_2000

Well, keep in mind I had nearly 500hp (2x of the original design) for nearly 35K miles!

CleanCL

iTrader: (4)

i know, and i woulld think you would have hurt more than just one cylinder. but it's possible.