GT Jts misfire - Injectors?
I've been having a problem with my GT. In short, a misfire developed after sitting in a traffic jam on a hot day a couple of weeks ago. This got rapidly worse to the point where the misfire was constant and not just under load. Once I got home I narrowed the misfire down to cylinder 3 and changed coil pack as this had been the problem in the past. Although it improved matters it hadn't cured it so I changed the plugs too. No difference. I then moved coil packs around but the misfire remained on No.3. I then did compression test and all appeared good (all cylinders around 230psi give or take 5), checked ignition system by doing flash test for each cylinder and again all was fine. Even removed each coil pack/spark plug combo to observe spark as engine was turned over. Again all fine.
I am now assuming the injector to be at fault. Is there any definitive way to check without removing injectors? I am wary of spending any more money as car has done 176000 miles and MoT is due in a couple of weeks and as it stands will fail on a number of counts which will cost in region of £400, even if I do most of the work. It might just be time to bite the bullet and get new car.
Any thoughts on easy cheap solutions? Is changing an injector possible for DIYer?
Thanks for any ideas