i need help please!!!!!!!!!1990 q45

[iculooking78]

Hello was wondering if anyone could help..i have a 1990 q45...I love this car but it has not run right since i bought it...i replaced the injectors and the car runs better but theres a hissing sound now like airs blowing out of somewhere and theres a miss...my mechanic is tired of working on this car so i wanna try myself...he said it seems that a cylinder is out and that bit may need a spark plug...i dont know if i should trust him anymore he keeps ripping me off...heres what it does...starts right up but has a miss...dosnt smoke at all...no visiable leaks...when i start off it shakes pretty bad...seems if i am under 2500 rpms its when its at its worst sometimes its harder to take off...if i floor it it goes with no shaking but once it gets to lower rpm it shakes again....sometimes it dosnt wanna take off too fast...any ideas what it could be please help...

[MinisterofDOOM]

I'm going to move this to the Q45 forum where our Q guys will be more likely to see this.

Welcome to NICO! You've definitely come to the right place for help with your Q.

[maxnix]

Start by reading the Timing Chain Guide Article.

Then please give us your recent maintenance history.

Welcome to NICO.