300e fuel injectors
 

how often should u chang the fuel injectors in a 300e 1991?
is it an easy job?
and what are the symtoms of bad injectors?
and how many does it take?
thanks

Those injectors should last the life of the engine..250K.
Somewhat easy job...should take less than 1.5hrs.

There are 6 injectors...1 for each cylinder.

mine has 268 kms, been running a little rough in idle when i start it, and whenu firsttake off, it doesnt have the pull.
do u think its time?
thanks

You may have more than one problem but rough shaking cold starts is a sign of bad injectors - injectors (some) that are leaking down and don't have immediately fuel pressure on start up, so some cylinders are firing properly and others are not. The price of those Bosch injectors has bounced around like pork belly futures - used to get them for $16 each, then they went up to around $45, now they are down around $30 or a little under. I would do it at that mileage - not that hard a job.

If your injectors are anything like on my 1991 300CE, then it is a very easy job. You'll need new seals and possible new holders. My holders looked reusable with some cleaning but I went ahead and just changed them. A set of ball allens will be helpful. Lot of grit and grime around here so you need to be careful. I changed 5 of my 6 injectors at 145m (removal of my cold start valve is needed for the last one) but turns out they were probably still OK. I incorrectly installed one and the car ran rough afterwards but the leak was obvious and easily fixed. I have the used injectors for sale if you are interested.

glenmore
los angeles
1991 300CE
2000 C280
1990 LS400

how can u tell which ones are bad when you take them out? or its just better to change them all out? would i get better gas mileage also?
I used fuel injector cleaner a couple of days ago, but i didnt notice much diff. i was gona clean the intake out when i get a chance. b/c i sprayed the litthe that i had left, then the car started up right away.
but now everytime i started it, i have to crank it for a while, and has a really cold start. also when i try to accelerate from zero, it kinda takes off slowly, then speeds up when i gun it.
i have another e320 1994, when i gun it from zero, it'll eat the asphalt under it.

thanks

Don't know what to look for with a bad injector except for what is obvious. All the ones I took out looked fine and the new ones made no difference to my car. I was trying to fix a slight stumble at startup. I use Techron fairly regularly. I started with changing the fuel filter and fuel accumulator but no difference. A lot of things could be causing your problems and as the vets here on the boards always suggest, throwing new parts at it is expensive and is hit and miss.

glenmore

i did notice after i came back off the high way there is a liquid, probably oil, in between the injectors and the oil cap area. maybe a leak from the cover gasket.

More likely vacuum leaks or bad cap and rotor than injectors.

Check for vac leaks first, especially idle control valve hoses, injector seals, and air horn boot.

Peter

I never changed them on W124 cars but did do them once on my W201 that had 130,000 miles and it made a big difference.

Try a can of BG44K and see how much of a difference you feel first.

http://www.autobahnpower.com/images/fsbg44k.jpg

Check if the seals are leaking air...
 

I used a carburator cleaner. I spray some cleaner around the injector seals, if there is a change in the engine sound, you need new seals...They are cheap compared to the injectors...

Good luck!

I have the same ones on my 87, 260E, >350K miles, I have changed the seals and used compressed air along with fuel injector cleaner spray to just clean them. Most of them make the same type of spray and sound, one or two had a different pattern and sound, but still sprayed o.k. If you put new ones, ofcourse they would perform better BUT given the condition of all other parts in the fuel injection system of my 20 year old car, they will not largely determine the overall performance. I would expect only a marginal improvement in the overall performance.