Tibi

Well gents.

For the past few weeks I have been having some random misfires. There isnt one specific thing that I am doing to cause the misfires, and they do not happen every time I drive the car.

Two weeks ago, at the track, at the end of the run the while downshifting the car made a loud exhaust noise and the check engine light came on. Cylinder 5 misfire.

Last week, driving down the highway just cruising and all of a sudden is sounded like a helicopter was above me, check engine light came on. Tried to accelerate car fell flat on its face, so I pulled over shut her down, looked around saw nothing wrong. Fired her back up and she drove fine. Code said cylinder 5,6,7 misfire.

Today, I was cruising with my parents in the car, and it repeated last weeks behavior. I haven't checked the code yet, I will check and post the exact code tomorrow. However I am willing to bet 5,6,7 misfire.

Mods:
MB 80mm tb
Cooling mist Water injection (windshield washer fluid with 2 cap fulls of meth)
FF Long tubes
Eurocharged tune

Could you gent help me narrow down where to look?
When doing a compression check should it be done WOT?
Need ideas, my drag setup arrived yesterday, so I would like to resolve this before Friday night.

Thanks

03'55AMG

When you say cooling mist water injection and 2 caps of meth with windshield washer fluid, I hope you mean water, not actual washer fluid....

Tibi

Washer fluid is perfectly fine. We have been through this and I and many others have been using it for ages. I am not spraying it for power, but for temp control.

03'55AMG

oh, didn't know, but good luck finding this gremlin

Jakpro1

Time to pull plugs but many times that indicates cat going bad. May be time to run STAR on it at stealer if you don't know of someone with one.

Tibi

No cats on this car, actually she runs open header most of the time.

The plugs were replaced before winter, and I have pulled them. I was thinking of going one step colder, as one of them does appear to have hot spots.

AMGPilot

and the bad advice from 03'55AMG continues

Actual washer fluid is excellent choice for a HE Mister....

GT-ER

Meth is pretty hard on spark plugs...at least the times I've used it my plugs life expectancy would go down considerably. Check your plugs...maybe they just need to be swapped out.

stevebez

Similar story 5/7 misfire with aquamist, but not under wot ... More on trailing throttle... Think some water pooling occurs during wot runs and when you come off the power quickly the remaining water gets dragged in when not needed... My theory anyway...

I got brand new one step colder plugs plus only use water and no meth

Tibi

codes are as follows:

p2098 bank 2 fuel trim too lean
p0134 02 no activity
p0135 02 no activity

surpirsed me no misfires. going to ask jerry to retune and see what haapens.

stevebez

Hmm ...

different codes to mine...
I got P0305 P0307 (5 & 7 misfire)
P0300 general misfire.

Closed loop, 18-34% engine load. Fuel trims on left bank out of wack. I think water meth in conjunction with deleted primary O2 (no primary cat) making ECU wobble a bit.

Where are you injecting the water/meth in the airflowstream ? I have tapped two location one just after I/C and one just infront of I/C after S/C. At mom I am using the latter location only.

I can manually activate / deactivate the water injection, and think I need to deactivate it during a WOT burst to purge any remaining water residue and then see if it still comes back. If it comes back after that then its something else thats going on with A/F measurement in closed loop.

When I took off the surge tanks to paint they were all nice and clean inside

stevebez

U can see a snapshot of my P0300 here

https://mbworld.org/forums/w211-amg/...0-low-rpm.html

Tibi

I am spraying it right after the intercooler core. My problems arent after wide open pulls. The last two check engine lights seem to occur when just cruising with cruise control on and no load. My meth only sprays under load at the top of 3rd thru 5th.

Jerry mentioned that it could be an exhaust leak, so this evening Im going to look at my header install and make sure all gaskets are still intact and that nothings leaking.

stevebez

Hmm I woud have thought you would have heard a leak .. mbe its the o2's ?

I had a leak on the opposite bank, but sorted that now, and now I get the errors on the other side... wierd!

jcjmw

If you have not already done so, you might want to check to see if the wires from the ignition coils are correctly connected to the corresponding/correct spark plug and cylinder. Good luck.

KLR CLS

Given the O2 sensor codes, I would think thats part of the prolem. No signal from O2 means ECU doesn;t know how to fuel the car.

Tibi

After speaking with Jerry and he recommending I check to make sure I didn't have an exhaust leak, I pulled the header flanges off and inspected all the gaskets and reinstalled. I also tested all my 02 sensors, and cleaned the connections.

Now things got worst. I am still getting the p2098 (post catalyst fuel trim too lean, bank 2), as well as 02 sensor 1, bank 1 (new code), and both rear no activity, and now rear 02 heater circuit.

When I use the code reader and watch the live data feed. Bank 1 & 2 primary sensors are working, the secondaries both show 0 (assume they should since they were turned off), and my long term fuel trim for bank 1 is 2.3 and bank 2 is 0.

I need ideas even shots in the dark like, take some air out of your tire or top off your coolant. I don't know where to go, maybe just buy new sensors and see what happens.

Thanks Gents

Roverron

Have you jump started the car; replaced battery or reset ecu?

Tibi

No jumpstart, battery replaced both batteries in the fall, and I reset (disconnected battery) the ecu this week while checking the headers.

Forgot to mention, with the code reader plugged in, the first warning did not pop up until 30ish mins into my drive today. Check engine light came on about 5 mins later. I don't know if that means anything.

ASP

Might be the O2 had the same issue only mine was cylinder 5-8 hope this helps

stevebez

I reckon its an 02 sensor ... mbe swap them left <-> right and see if the code shifts banks?

TTMotorsports

Did you try to turn the meth off and see if the problem persists?

When you spray after the intercooler your nozzle is most likely directly across from the MAP sensor and about 3" from the IAT sensor, correct? The nozzle should be before the intercooler core since then it will have enough time to atomize and not cause MAP and IAT sensor failures prematurely. That is the best spot for the nozzle. What size nozzle are you using 5 or 7?

1 step colder plugs is a great idea to pull some heat out of the combustion chamber.

I would definitely get this resolved before going to the track.

GL with finding the issue. Steve's suggestion about swapping the O2's is a great start.

Zod

the FF setup requires you to extend the o2 sensors....how did you do that?

Tibi

Cut and solder on the 02 side, each solider point go shrink wrapped, and the the whole ensemble go wrapped up.

Tibi

I am going to have to loook for the met kit receipt to see which nozzle I got. Today I will shut the system off, and swap all the 02s, to see what happens.