dantodd

Hi All,

Been reading on and off for some time.

I bought my C43 new and love it to death.

Recently it has taken to bogging down when I jump on the throttle. It is especially noticable when not fully warmed up and from a fulll stop. If I get all the way into the throttle it will sometimes refuse to answer the call and run like it is fuel starved. If I keep in the throttle it will continue to bog and simply won't pick up speed. If I back off to half it runs just like normal.

After doing this for a little while it finally threw a couple codes but they were both for misfires. Sort of hoping it was a lean code.

Took it to the shop and had the mass air sensor replaced; it made some improvement but it didn't completely solve the problem.

I've also recently had the fuel filter replaced since it has nearly 30K on the filter.

I can still hear the intake and it sounds the same as always. I suppose it could be ignition related but with 8 coils it's hard to believe that I could see a complete loss of power! Plus backing off the throttle shouldn't really imrpove thing if its ignition, should it?

I also had my plugs all changed at the last service and they all looked fine. None were burned, pitted or gunked up at all.

Any other ideas? I'm sort of at the end of my rope here!

linuxfoo

hey dan,
where did you get your car serviced when you got your spark plugs replaced? having a reputable mechanic perform this is a good idea and here is why, the engine compartment is very very tight espcially towards the rear of the engine. some mechanics will have tendency to just yank on the plug wires to get them out because of the limited space between the engine and the firewall. when you yank on the plug wires, and trust me some of thses are on really tight due to suction effect - you can damage the inside of the plug wires (separation). from the outside, the plug wire will look normal and only using an OHM meter can tell you wether the plug wires are good or not. all 16 wires should have about the same resistance, if one is off, that wire is bad. this could be the reason for your engine misfire. i doubt that the coil pack is bad. look into teh cheaper solution first, wires then look into the coil packs.

dantodd

Thanks LinuxFoo

Guess I should have been a little more specific. The problem started before I had the fuel filter, spark plugs and Air Mass Sensor replaced.

The work was done by a reputable shop (20 years in the area) even though he is a bimmer specialist!

I suppose it is possible that the Air Mass Sensor was the problem and then this is a new problem with the same symptoms from a trashed plug wire but I doubt it.

I might just yank the wires and check the resistance. Though the whole reason I had the shop do the change is tha my fat fingers can only reasch about 1/2 the wires!

linuxfoo

hahah yeah i feel ya, i been doing work on my own cars for quite some time now, even engine swaps on my Rx7, but man this c43 engine in the little compartment = no sapce to work with. it took me about 2.5 hours to change all 16 plugs. also for the plug wires, you should get a very long 90 degree pliers, can't exactly explain it other than it looks like a plier on steroids- its long. the amg tech at the dealer here in the bay area showed me what he uses and it was a very long 90 degree or so pliers - clamp it on the metal body of the plug wire and carefully pull it and it will pop out easily, you should never pull on the wire itself.

also post your codes you pulled, maybe we can be of better help.

dantodd

thanks,

I'm in San Carlos BTW.

The guy who pulled the codes told me they were misfire codes, I didn't get the numbers or see the display at that time. He did show me the display later to watch the cylinder data as it ran and there was nothing out of the ordinary.

If you have a recommendation on a good shop in the area I'd appreciate it!

cheers,
dan

linuxfoo

i'm in emeryville, and if you ever come by this way, you can use my scanner. also i was reading up on the fault codes and there seems to be two types, a generic - just stating that there was a misfire (P0300) and also a specific one stating which cylinder had the misfire (P03XX), where by the xx is the cylinder number. man if the codes displayed a more spefic code, then you can try and isolate the problem to that cylinder only. i hope for the best for ya and i hope its not something that is too costly.

dantodd

thanks, I appreciate it. next time I get the light on I'll def. try and hook up with you so I can see first hand which code it is throwing!

hate to say it but my main goal here is to get the car ready to sell. I am buying a new Magnum SRT-8 so my son's wheelchair is easier to move around.

steve s

the rental magnum i tried, altho handles surprisingly well and flat for a large car, feels very claustrophobic...

hionchee

My C43 is doing the a similar thing, from standstill, it seems to be sluggish until I reach approx 4000 rpm. Could it be that the MAS sensor needs changing on my car, 'cos I dont have any warning lights on the Dash.

The last service was done Approx 3K miles ago (B Service) and nothing was highlighted by the Dealer.

Please help, I need the extra power to carry on giving my neighbour in his Boxter grief each time I see him on the road.

ProjectC55

change the mass.sounds like it's time for a new one even though the CEL light is not coming on.

hionchee

My extended warranty papers just came through this morning. The policy is a Tier 1 so it looks like the MASS is covered. Just out of interest how much does a MASS go for on a C43 - any takers??

ProjectC55

190-250.00 depending where you go and who you know.Any takers?Who's gonna want your used Air Mass?

hionchee

Sorry "Any Takers" is a UK Expression meant to imply the cost of a new item and not necessarily any purchasers of a used item.

Sorry about the confusion - Just shows how a small pond like the Atlantic Ocean can alter the meaning of a sentence in the same Language.

ProjectC55

LOL!

s0vietbenz

When you say Bog do you mean the car jerks a few times?

hionchee

Sorry for delayed response to your post (a bit like the power delivery on my car ), yes the car jerks like F*ck and then all of a sudden the power comes on between 4000 RPM and redline.

StapleGun

Boy, this thread sounds all too familiar to me....

ProjectC55

you took the wrds outta my mouth!

StapleGun

Mr Todd,
Keep us posted on what the cure might be.

hionchee

Gave my C43 to my local MB Dealer and asked them to change the MAF sensor and also remap the Transmission. My C43 now kicks *** like never before. Just slam the Gas pedal from standstill and the power delivery is smooth and progressive. AT 4000 RPM - the serious fun begins and boy does it feel good.

Looks like my Neighbour in his Boxter is in for more stick each time I see him

StapleGun

You paid for a MAF replacement from "stealer" this is a 15 minute DIY job....what'd you spend?

hionchee

I would normally have had to pay but as the car is under the warranty - it didn't cost me a penny

If I did have to pay for it myself, I'd seriously attempt it myself as MB Service / Labour charges in the UK are £80.00 per hour (approx 120.00 USD).

BTW can anyone on the forum recommend a good service guide / manual for a C43. I purchased a CD rom from Ebay and it's a complete bag of S*it. All it tells you is the specs of the car and other crappy stuff.

ProjectC55

Did'nt I tell ya!

hionchee

You da man Coolcarlski

StapleGun

Hionchee:
Glad to hear it was done under warranty....fortunately an easy fix!