Rough Idle and Limp Power
Re: Rough Idle and Limp Power
I've reread this whole thread 2x. People keep suggesting the same items to you:
- 1st have codes read. We can help better if we know what the computer is seeing as the fault
- Check PCM soldering and resolder or replace if it's bad
- Check for a vacuum leak, possibly under the throttle body
One question, did you replace the CPS with an OEM Bosch one? I know people have had terrible luck with the others. FWIW, the CPS was the problem with mine when I had very random/intermittant problems with idle and starting.
- 1st have codes read. We can help better if we know what the computer is seeing as the fault
- Check PCM soldering and resolder or replace if it's bad
- Check for a vacuum leak, possibly under the throttle body
One question, did you replace the CPS with an OEM Bosch one? I know people have had terrible luck with the others. FWIW, the CPS was the problem with mine when I had very random/intermittant problems with idle and starting.
Re: Rough Idle and Limp Power
I just had this same issue with my CPS. My shop replaced it with another brand and the engine kept cutting off. When I put the BOSCH in everything was back to normal. Goodluck.
If your getting limp mode as well check your trans electric plate too I had the same problem.
If your getting limp mode as well check your trans electric plate too I had the same problem.
Re: Rough Idle and Limp Power
Alright. I did replace it with a cheaper model so I suppose I'll bite the bullet and buy the Bosch unit, but not before I have it checked for codes. I've never had it worked on at anywhere other than dealer--would an Autozone or Advanced Auto Parts be able to check?
Re: Rough Idle and Limp Power
That's their reply because either 1) they don't know squat about cars and "soft codes" set in memory or 2) don't feel like helping you. I've worked part time on the side at an auto parts place and can vouch for both of those statements.
Best advice: drive into one of the places and just say, "I need my car scanned".
Best advice: drive into one of the places and just say, "I need my car scanned".
Re: Rough Idle and Limp Power
Read this thread too. Tried to provide my thoughts in order of simplicity.
1) Remove the plastic guard that covers the fuel pump (pretty close to directly underneath the trunk/behind the exhaust tips) and check all those rubbers hoses going in and out of the fuel filter. I have posted another thread about this but that rubber has rotted on many of our cars after 8 years and if you have a hairline tear in one of your pressurized fuel pumps (I posted up a diagram in the same thread indicating which hose is which) your car could be stuttering because there isn't enough pressure in your fuel line (ask me how I know).
2) How old is your battery? You need a new one if you are (hopefully not) still using the OEM battery. Cars will do weird things when the battery starts to go and this would be a straightforward thing to do + preventative maintenance item as well.
3) https://www.crossfireforum.org/forum...-no-start.html Perhaps check this out (what others a referring to when they talk about pulling out the soldering iron).
4) As others have mentioned, you can try the CPS issue but your symptoms are different from what I and others have had when the CPS goes bad (my car would literally just die, once at 60mph and once at a stop light). I would exhaust other options before this.
1) Remove the plastic guard that covers the fuel pump (pretty close to directly underneath the trunk/behind the exhaust tips) and check all those rubbers hoses going in and out of the fuel filter. I have posted another thread about this but that rubber has rotted on many of our cars after 8 years and if you have a hairline tear in one of your pressurized fuel pumps (I posted up a diagram in the same thread indicating which hose is which) your car could be stuttering because there isn't enough pressure in your fuel line (ask me how I know).
2) How old is your battery? You need a new one if you are (hopefully not) still using the OEM battery. Cars will do weird things when the battery starts to go and this would be a straightforward thing to do + preventative maintenance item as well.
3) https://www.crossfireforum.org/forum...-no-start.html Perhaps check this out (what others a referring to when they talk about pulling out the soldering iron).
4) As others have mentioned, you can try the CPS issue but your symptoms are different from what I and others have had when the CPS goes bad (my car would literally just die, once at 60mph and once at a stop light). I would exhaust other options before this.
Re: Rough Idle and Limp Power
So just for giggles, I pulled my RCM last night to look at it. I'll be damned if mine didn't have some cracked solder connections too! About 45-min start to end and mine is resoldered and back in. You would need a magnifying glass to see the cracks, but they were there. Definitely worth a try, esp as it's a free fix... I used that link posted above.
Re: Rough Idle and Limp Power
Hello Fellas,
Well, it all hit the fan yesterday. I was on my way back home from school (about a 40 minute drive) at around 3 o'clock. As I came to a stop at the red light right in front of the entrance ramp to the interstate, the car began that familiar, violent shake and marginal throttle response. I immediately changed lanes to pull into a parking lot of an abandoned garage, but evidently asked too much of the throttle and the car died, with all the dash lights coming on. Not again! After about 45 minutes of attempting to restart the car without the shake so I could at least get home, it was to no avail.
As I was in a sketchy part of town, I was getting funny looks from the crowd walking on the side road, so I decided it in my best interest to put my flashers on and creep down to the nearest parts house. The first, less than .5 mile, was an O'Reilly. Went in and got the gentleman working the counter to come out and check for codes for me, so I at least knew where to start. It generally read that it was "low engine voltage." He advised me that this was too vague of a reading and I should take it to a specialist. Well, I crept on down to the nearest dealership, Action Nissan in Nashville. At this point, I was just looking for a safe place to chill and to figure things out.
I ended up waiting at the dealership for ~3 hours for the tow truck after realizing that i was stranded and something had to be done with the car, and me. Haha. They were more than welcoming at the Nissan dealership and invited me to get complementary coffee, water and popcorn. I even spent some quality time with a new $98K GT-R in the showroom as I waited. Right before the tow truck arrived, I tried the engine one more time only to find it was experiencing the same issue. This was the most persistent it has been. Now 7 o'clock, the tow truck finally arrived. I went out to move the car so that he could pull it onto the flatbed. It started right up--no issues. Frustrated, I went ahead and had him take it to Franklin Dodge & Chrysler, the only place I will let service the car. They have a dedicated "Mercedes Tech" specifically for their Crossfire clientele.
They haven't had the time to fully check everything out, but the tech called today and advised me that it could simply need a tune-up, could be a spark plug(s), or could possibly be something with the throttle body, all of which have been mentioned throughout this thread in some estimate. I guess this is what I get for being too busy to find time to diagnose this myself. I also, however, lack the expertise, time or luxury to just trial-and-error this issue until I get it right, because I am either at school where I do not have the space or tools, or at home, where I don't have the time because of work. Plus, the problem is intermittent and temperamental, so there is no immediate way of knowing if a change is actually the solution. So for these reasons, I don't mind serving as the guinea pig for the issue. I'm going on vacation for a few days to get away from all of this.
I will keep you all posted as it all progresses. Thanks for all the advice and for sticking with me! As he was pulling the SRT onto the truck, I realized I couldn't be mad at the car. She's so beautiful, even incapacitated on the back of a truck!
Well, it all hit the fan yesterday. I was on my way back home from school (about a 40 minute drive) at around 3 o'clock. As I came to a stop at the red light right in front of the entrance ramp to the interstate, the car began that familiar, violent shake and marginal throttle response. I immediately changed lanes to pull into a parking lot of an abandoned garage, but evidently asked too much of the throttle and the car died, with all the dash lights coming on. Not again! After about 45 minutes of attempting to restart the car without the shake so I could at least get home, it was to no avail.
As I was in a sketchy part of town, I was getting funny looks from the crowd walking on the side road, so I decided it in my best interest to put my flashers on and creep down to the nearest parts house. The first, less than .5 mile, was an O'Reilly. Went in and got the gentleman working the counter to come out and check for codes for me, so I at least knew where to start. It generally read that it was "low engine voltage." He advised me that this was too vague of a reading and I should take it to a specialist. Well, I crept on down to the nearest dealership, Action Nissan in Nashville. At this point, I was just looking for a safe place to chill and to figure things out.
I ended up waiting at the dealership for ~3 hours for the tow truck after realizing that i was stranded and something had to be done with the car, and me. Haha. They were more than welcoming at the Nissan dealership and invited me to get complementary coffee, water and popcorn. I even spent some quality time with a new $98K GT-R in the showroom as I waited. Right before the tow truck arrived, I tried the engine one more time only to find it was experiencing the same issue. This was the most persistent it has been. Now 7 o'clock, the tow truck finally arrived. I went out to move the car so that he could pull it onto the flatbed. It started right up--no issues. Frustrated, I went ahead and had him take it to Franklin Dodge & Chrysler, the only place I will let service the car. They have a dedicated "Mercedes Tech" specifically for their Crossfire clientele.
They haven't had the time to fully check everything out, but the tech called today and advised me that it could simply need a tune-up, could be a spark plug(s), or could possibly be something with the throttle body, all of which have been mentioned throughout this thread in some estimate. I guess this is what I get for being too busy to find time to diagnose this myself. I also, however, lack the expertise, time or luxury to just trial-and-error this issue until I get it right, because I am either at school where I do not have the space or tools, or at home, where I don't have the time because of work. Plus, the problem is intermittent and temperamental, so there is no immediate way of knowing if a change is actually the solution. So for these reasons, I don't mind serving as the guinea pig for the issue. I'm going on vacation for a few days to get away from all of this.
I will keep you all posted as it all progresses. Thanks for all the advice and for sticking with me! As he was pulling the SRT onto the truck, I realized I couldn't be mad at the car. She's so beautiful, even incapacitated on the back of a truck!
Last edited by smokey847; 03-14-2013 at 05:09 PM.
Re: Rough Idle and Limp Power
Still running the "Yung Man Stuk" version or did we switch to Bosch? Might mention to tech ... could save a few hours diagnostics time...
Re: Rough Idle and Limp Power
Okay...
6 miles into my 32 mile trip to work.. she died.. 10 minutes of sitting and waiting and trying she fired up... all the way to work not a problem.. fired up after work.. 2 miles over to Red Box machine and then she wouldn't start again. Just saying they don't necessarily die and be done.. Ex wife's intrigue played the dying game for a year before CPS was figured out.. divorced at the time so it wasn't my problem to figure out... LOL
And other members have reported "hot".. cooled off and started scenario's... Just saying..
6 miles into my 32 mile trip to work.. she died.. 10 minutes of sitting and waiting and trying she fired up... all the way to work not a problem.. fired up after work.. 2 miles over to Red Box machine and then she wouldn't start again. Just saying they don't necessarily die and be done.. Ex wife's intrigue played the dying game for a year before CPS was figured out.. divorced at the time so it wasn't my problem to figure out... LOL
And other members have reported "hot".. cooled off and started scenario's... Just saying..
Re: Rough Idle and Limp Power
not true at all. Mine started and ran fine until I stepped on the gas hard and it died. Urs is a different occurance with the CPS then I had, but my money is on the non OEM CPS.
I would get the Bosch CPS and have ur tech install it. Start from there. Then work to the RCM. Goodluck I have been in ur shoes numerous times with this car.
I would get the Bosch CPS and have ur tech install it. Start from there. Then work to the RCM. Goodluck I have been in ur shoes numerous times with this car.
Re: Rough Idle and Limp Power
Don't know if it works on modern cars but next time it rains at night look under the hood for lightning.
Re: Rough Idle and Limp Power
Alright, I'm calling in some forum wisdom here.
Received a call from the dealership this morning. Bryan from Franklin Chrysler, Dodge & Jeep told me that the car was not showing any codes. I reminded him that the O'Reilly I stopped at was showing a Low Voltage code, of which he took note of. Of course, because no codes are are showing, they're suggesting a guess & check method. They want to start with a tune up--specifically, spark plugs (which they want $700 to replace), transmission flush, etc. In this same round, they're wanting to go ahead and replace the throttle body, which is a $1300 part. Quite obviously, I'm not to keen on throwing around this kind of money, (a grand total of $2800) with no real guarantee that it will fix my problem. The car has never had a "tune up," so I'm thinking this may be a good place to start. But if a plug was causing a problem with a misfiring of a cylinder, would it be this intermittent?
I feel like I'm being bent over and need some advice. Please help!
Received a call from the dealership this morning. Bryan from Franklin Chrysler, Dodge & Jeep told me that the car was not showing any codes. I reminded him that the O'Reilly I stopped at was showing a Low Voltage code, of which he took note of. Of course, because no codes are are showing, they're suggesting a guess & check method. They want to start with a tune up--specifically, spark plugs (which they want $700 to replace), transmission flush, etc. In this same round, they're wanting to go ahead and replace the throttle body, which is a $1300 part. Quite obviously, I'm not to keen on throwing around this kind of money, (a grand total of $2800) with no real guarantee that it will fix my problem. The car has never had a "tune up," so I'm thinking this may be a good place to start. But if a plug was causing a problem with a misfiring of a cylinder, would it be this intermittent?
I feel like I'm being bent over and need some advice. Please help!
Re: Rough Idle and Limp Power
Spark plugs.. $100 ("version" dependent) plan about 2 hours for installing yourself (12 plugs)
Throttle body - what we N/A owners upgrade to for about $150 and about an hour to install
CRANK POSITIONING SENSOR.. $45 bucks.. has seen issues..non start on SRT6 and no code thown.. off brand..
Your money but the voices of experience here really suggest start with that sensor..
Throttle body - what we N/A owners upgrade to for about $150 and about an hour to install
CRANK POSITIONING SENSOR.. $45 bucks.. has seen issues..non start on SRT6 and no code thown.. off brand..
Your money but the voices of experience here really suggest start with that sensor..
Re: Rough Idle and Limp Power
Alright, I'm not quite comfortable or familiar enough with the underpinnings of the car to change the plugs myself, but I have a good friend who would for a small fee. Is this $100 for OEM plugs?
Also, would you direct me to the throttle body you mentioned? Thanks for the help thus far.
Also, would you direct me to the throttle body you mentioned? Thanks for the help thus far.
Re: Rough Idle and Limp Power
They aren't fun to get to.. but they are doable.. search here will bring up a few tips on them.. And here is your "top of the line" versions..
NGK Iridium IX Spark Plug Set Stock Heat range
And there is a thread on easy peasy throttle body replacement.. here's some leads on the 74mm.. which is what you are running..
https://www.crossfireforum.org/forum...y-upgrade.html
NGK Iridium IX Spark Plug Set Stock Heat range
And there is a thread on easy peasy throttle body replacement.. here's some leads on the 74mm.. which is what you are running..
https://www.crossfireforum.org/forum...y-upgrade.html