Heya, I have a 2006 Honda Jazz and my car has been getting progressively worse where it kinda stalls like you didn't rev it enough when putting it into gear, but then it doesn't actually stall. I've noticed it happens around the 1.5 thousand rpm mark, and it gets better if I put in injector cleaner but only for a while

I have in the time that this has been a problem:
Replaced the battery
Replaced the spark plugs at a mechanic
Had another mechanic realise the back plugs were missed and replaced them
Replaced the ignition coils
Cleaned the EGR valve
Deleted the EGR valve

Also I had the gearbox replaced at one point because it got shredded.

I can't seem to find any explanation as to what to do, and every time I have taken it to a mechanic (5 different ones so far), they just say to replace the spark plugs and/or coils - which I have done already.

Please help

 

Valve adjustment. Just did it myself on my daughter's 2008 with 210k miles and it is so smooth now.

https://youtu.be/Ayzy6iHgbio

 

Yes, spark plugs and coils would be main suspects, but if that does not do it, then...many other things could cause it.......fuel filter, fuel pump, injectors, temp sensor in air box, rehostat in electric accelerator pedal.......Yes, valve clearances could be a factor. These engine does not have hydraulic lifters......and clearances have to be checked sometimes.......those are things that come to mind right now.

 

Thanks heaps. Lots of those have already been tried/replaced.

One of the early tests a friend tried was to disconnect the air box and seal the intake with a hand. The engine did not stall and air could be heard moving through somewhere that wasn't past the hand (but we couldn't find where). A mechanic dismissed this as unrelated to the problem. Could it be worth investigating a leak in one of the air hoses or is this just a normal part of some emissions equipment somewhere?

 

do you know how to perform a smoke test? seems like your friend noticed some air leak sound and started messing around with intake. smoke test can help you track vacuum leaks as it come be a host of things like valve cover, manifold gaskets, throttlebody gasket leak or even loose vacuum hose. clean map sensor then check for vacuum leaks, thats what i would do first.