(T) Bravo 1.2 16v poor acceleration

Greetings to all members.

So... It as a car from title above, 2001. Millage is 90000 and since i bought it from a "friend", he said all the filters and belts were changed. Only thing i am sure it is changed is oil and oil filter, i didn't checked the other stuff.
Engine is behaving like I am having 5 big elephants on my back seat, but only up to 3000rpm. After that, elephants are vanishing or falling out of car,I am not sure and the feeling of acceleration is great. This is best noticed in second gear. My friend have Punto Mk3 and it is accelerating much better. Some local repair guys told me that this is normal for my car, since it has 16v. Any other comment on this statement is crazy.

There was a faulty lambda sensor, but it was changed and now there is no ECU light anymore.

I decided to fix this myself if I can. I have most of the tools necessary for repairs and enough mechanical knowledge.
I swept the forum for answer, and there are many similar problems, and there are as many similar solutions... maf sensor, map sensor...

Where to start, if there is someone here who is willing to guide, I'll be more than greatfull.

Just to add... Car is idling at 800rpm, but every few seconds it seems like the engine is going to turn off.

Don't know if it's the same but my car had the same problem for a while. Turns out I was only running on 3 cylinders as one of the spark plug leads had developed a hole and so was shorting out. Worth a try, check the spark plug leads and check that none of them have any holes anywhere.
Although my ECU light came on, so I don't know really lol.

Leads are new, but i'll check them anyway. ECU light is off, since lambda sensor was changed.

well for that idle... its obvious that theres something ecu dont like, if he tryes to fix it it looses rpm so does what is needed to keep it running...
i bet lambda have never been real problem...
just get diagnostic to look realtime data... there SHULD be something off...
or some silinder not working etc.... all silinders work btw?

Well, i think they are all working. But I will do exactly what you said, because I have a friend of a friend who have equipment for diagnostic.

and make sure u check everything... coz no checklight on, it cant be WAY OFF > it must be "truthful" for ecu, so u can look at temperatures > if they are alot different from real might coz problems.
so check everything u can... and if it has MAF u shuld check it too, and other air way, that it wouldnt be blocked/leaking.
if u can, u could look pressure for silinders, maybe worn or something like that.
do u have oil in limit? does it lose oil.

try cleaning maf sensor and do an ecu reset.. see here

it happened to my car when i bought it. it was very sluggish and came came back to life after i did the above.... this should solve the problem

Diagnostic will be done tomorrow. I was looking for MAF sensor, but it seems like i don't have one.Can ECU read silinder pressure trough MAP sensor, and all of that trough diagnostic software? Cause, checking the real pressure with gauge could be a problem in the moment, since i don't have one. Oil is 1mm over maximum, and in last 4 weeks it didn't loose any oil.
When I bought a car, a month ago, it was runing smoothly with more power and good acceleration, problem became visible maybe 10 days after i got it. And uneven idling 10 days ago. But all of that was blamed on lambda sensor.

well i bet u cant see pressure from ecu since theres no sensor for that.
oil over max, can coz some trouble, i cant tell u for sure what/how serious -not expert.

would recomend to test ur silinders work. 1st remove sparkplugs and look for any signs that would lead for some silinders problems etc. u can take pic and put it up if they are all nice and fried, then it isnt problem on single silinder probably...
and u could look for timing belt, if it might have jumped a teath or 2. just look, if it is tensioned correctly etc...


heres few things i would think of... i am just a fiat owner so i might be wrong gl