Hi all, I'm in tremendous need of some help. She just got this 300E, and this is the first benz in my family. I must say it is a very nice car, and can understand why you love your Benz!!!!!!!
When she got it it ran terrible when cold. We replaced 2 10-amp fuses on top of the OVP I think is what its called. Wow, What a difference that made! It fires right up, and runs smooth! The day that I did this it started dying once in awhile like 4 times a day running around town. When it dies it starts right back up and runs fine. she will put 100 miles running around town n 1 day. The way she explains it it dies when she slows down to make a turn. Never does it die on the road when its under a load. When i replaced those fuses it brought the idle up to 9 or 10, and before it idled at 6, but ran like crap until it got warm. I dont think idle has anything to do with this. Also the fuel milage went from 21 mpg to 17. Any help at all would be appreciated.
Thanks,
Big John
Last edited by jsbigone : 11-03-2007 at 04:55 PM.
Reason: more info
Have you checked for vacuum leaks? Also, might be time for a new O2 sensor if the mileage is dropping precipitously without a radical change in driving habits.
Hi all, I'm in tremendous need of some help. She just got this 300E, and this is the first benz in my family. I must say it is a very nice car, and can understand why you love your Benz!!!!!!!
When she got it it ran terrible when cold. We replaced 2 10-amp fuses on top of the OVP I think is what its called. Wow, What a difference that made! It fires right up, and runs smooth! The day that I did this it started dying once in awhile like 4 times a day running around town. When it dies it starts right back up and runs fine. she will put 100 miles running around town n 1 day. The way she explains it it dies when she slows down to make a turn. Never does it die on the road when its under a load. When i replaced those fuses it brought the idle up to 9 or 10, and before it idled at 6, but ran like crap until it got warm. I dont think idle has anything to do with this. Also the fuel milage went from 21 mpg to 17. Any help at all would be appreciated.
Thanks,
Big John
It is air intake valve - I had the same problem with my 190e - at turns and at braking the engine would die - it would start right up -
this is what it look like: http://www.autohausaz.com/secure/Par...0280140510.jpg
Regarding cold start problmes, I'd meter the coolant tamp sensor at the back of the cylinder head. It's a thermistor that tells the fuel injection system whether the cold start injector is required and also how much fuel to inject. When these fail they ususally go "open" so the computer thinks the engine is hot all the time.
The OVP name is misleading becasue that component does many, many things. The fuel pump relay (right next to the OVP) is also much more than a simple relay. It is actually the component that activates the cold start injector, limits engine RPM, and even handles kickdown control. Each of these "relays" has been updated many times since the cars were new and one part can fail while other parts continue to function. While not cheap, it is worth your while to buy a new pair, install them, and put the old ones in the trunk for emergency use.
As StarGazer says, check the air intake (idle control) valve. Sounds like it is gummed up. Idling at 9 or 10 (900 or 1000 RPM) is much too high. Either the valve is stuck open or the rubber pipes to/from it have cracked.
I appreciate everyones help. The car idles at 9 to 10, and when I unplug ICV the idle drops to around 6. Does this sound like the ICV is bad? It does have a new OVP on it. I am disabled so I cant do alot of work at one time, so I'll keep everyone posted.
Thankyou to everyone who has replied,
Big John
The ICV could just need a cleaning, take it out and soak it in throttle cleaner.
I would also take heed to what was said above and check the O2 sensor.
I removed the ICV and soaked it. changed hoses to and from. I hooked up the electric to it and had someone turn it over. It opened all the way. So that tells me its working. Put it all back together and took off. It ran so rich it was blowing black smoke. finally after about 4 miles i stopped at a stop sign and then took off and it ran fine and accelerated. Wouldnt even eccellerate when i first took off.
Any suggestions?
Big John
My wife's '89 got to a point where it would just die while driving and then start right up. I heard about the fuel pump relay problems (mentioned earlier in this thread) and checked the date code on it (it was original - '89 but this was in '99). I replaced it and it never died again. I have heard of this problem on multiple occasions. Why not pull the relay and see how old it is. The next thing to do if you don't want to buy a new one is to go to the local boneyard and peruse the 124s. Pull the fuel pump relay and check date codes on them. Buy the newest one(s). While there pull an OV relay too. Don't bother checking anything else until you've done the two most simple possible solutions.
My wife's '89 got to a point where it would just die while driving and then start right up. I heard about the fuel pump relay problems (mentioned earlier in this thread) and checked the date code on it (it was original - '89 but this was in '99). I replaced it and it never died again. I have heard of this problem on multiple occasions. Why not pull the relay and see how old it is. The next thing to do if you don't want to buy a new one is to go to the local boneyard and peruse the 124s. Pull the fuel pump relay and check date codes on them. Buy the newest one(s). While there pull an OV relay too. Don't bother checking anything else until you've done the two most simple possible solutions.
Good luck.
Thanks buddy, I will check that. I appreciate the feedback so much!!
Big John
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