Hi all, I have a 1.8i m10 which i have started having problems with lately. Here goes.
It started out on rainy miserable days, i would be driving mainly in the mornings and it would splutter like nothing else i couldnt even get to 2000rpm. as i went on it got better. then for some reason this stopped happening and it was fine. i went for a trip in the car and on my way back (in the rain) my car started spluttering again, the lower i let the rpm drop the harder it was to get back up to 3000rpm. as soon as io put my foot down it splutterd really bad. so when i got home in went a new dizzy cap, rotor button and plugs. I then swapped my fuel pump with another i had from my previous e21. all seems fine, sometimes. Now there is a new problem. I rev 1st to 3500 then change and as soon as the clutch is out it dies totally and then kicks back in and away i go. so i swapped my fuel pump back to original but it still does it alot of the time. i have been forced to change at 1500-2000 but it has done it this low as well once. today though it seems to rev to 6500 and change fine so i am stumped as to what it is?
any help please?

check for vacuum leaks, check for moisture at the coil. check the 02 sensor if you have one.....

The O2 sensor will not cause the car not to rev. If the O2 sensor goes bad all that will happen is the car will have an uneven idle but it will rev out fine. It sounds like you have a very large vacuum leak, or the air meter flap is sticking and not allowing the proper ammount of fuel to flow through the injectors. Also if it hasn't been done you should change your fuel filter, it should be changed once a year or every 25,000 miles, whichever comes first.

You might wan't to check your plug wires for cracks. I washed my motor and found out my wires were toast. It wouldn't run right till the wires dried off, then it ran fine. Jay

I will check the plug wires, they are 9mm stainless ones i had made up from some guy interstate. I have replaced the fuel filter about 2 months ago when i have been swapping the pump and (accumulator?) i have been blowing it through to make sure there was no blockage. I have one more hose to replace (the one from the valve cover to underneath the injection and then they will be fine, and if it still is a problem i might pull off the k-jet and check that air meter flap. I have been paying alot of attention to the engine swap thread as i am thinking about a few of them for me so i just want this m10 to hang on for a little bit more, but i think it knows thats what im thinkin and so is getting me back by makin me spend money on it. hahaha