hard starting after injector change???? - PeachParts Mercedes-Benz Forum

h_shek · #1 05-04-2003, 09:16 AM

Firstly thanks all for the input regarding my injector leak.

I got my car back from the mechanic due to a leaking injector causing greese around the injector and on the engine. I had 1 injector (#5) replaced to fix this potential fire hazard.

Anyway, my problem is, after I got my car back, I can't seem to start it the way I could easily do before. It takes 2-3 times inorder to start the car.

My Mechanic says is not related to the repair. I don't really believe that as I don't have this problem before! I will bring it back but I want to see if I can get some pointers from you experts here.

Together with the fix, I also changed fuel filter, oil filter, engine oil, spark plugs and the #5 injector. The car is fine after started, goes well and no shaking. Just hard to start!!

I tried to pin point the problem and no matter its a cold engine or hot engine, its the same, takes 2-3 times. I also tried turning the key to number 2 position and waited 10-15 seconds before starting. Same. I do hear the "buzz" noise from the rear which I believe is the fuel pump pumping fuel from the back.

I am puzzled and I know my mechanics is going to say computer replacement as he already said over the phone. Any input you guys can give? pointers?? fuel pressure perhalps?? I did notice when I got my car back, one of the harness to the CT sensor was not pluged in fully. This has lead to me thinking the ECT and CT sensor is faulty until I double check last night. (Thanks to Jimf, my life saver) Do you think some sensor have not been connected properly?? (I think my mechanic have to unplug the harness to remove the entire fuel rod on top of each injector)

Anyway, any input is greatly appreciated.

Car in concern?? W140 M104 engine, 300SE 92 Petrol car

sbreisch · #2 04-20-2005, 09:36 AM

I have pretty much the same story except that since Nov04 after a dealer visit, my starting slowly got worse. It used to be OK on a cold morning start but now, cold or warm I got the same issue. I tried fuel injector cleaners and leaving the key in #2 position for 10 seconds, no change, which is why I am on "the site" now.
I'll let you know if I get anywhere and i'll watch your post. I am leaning towards the fuel filter, check valve or accumulator, but I hate to just through money at it.
Steve

I should of added...I had it in for new plugs, caps, rotors, sparkplug wires, and a few new vaccum lines to fix a rough idle problem. It is a W140 1993 500sel.

kth286 · #3 04-20-2005, 01:27 PM

h-shek

Are the new spark plugs the same type and number as the old ones that were pulled out ?

Regards

EricSilver · #4 04-20-2005, 02:54 PM

I had the same thing happen.

You need to adjust your fuel/air mixture. The leaky injectors were admitting excess air. If you were running lean or rich back then, you are running *really* lean or rich now, thus the excess cranking.

Blipping the accelerator, in my case, gets things fired up quickly when I don't want to wait the extra 2 seconds to start. (I never readjusted my mixture. I run lean to ace my emissions tests.)

There is nothing wrong with your computer.