I would run the car in regular traffic for at least 20-25 minutes.
Simply idling the engine will not be able to achieve a good warm-up quickly effectively.
When removing the injectors, make sure that you are ALWAYS pulling the bar towards the engine and not away from it.
This would look like this:
stay on the right side of the car (passenger side in USA)...
You`ll be applying force counterclockwise so it is highly suggested to do it from this side of the car , this will help you avoid applying force into the wrong direction. Try to not apply force downward and also do not apply too much force away from the engine.
It is maybe not a straighforward explanation here but basically you are working with a sensitive injector casting at the injector inlet, SO you are highly suggested to do it the right way (=preventative)...
By standing on the passenger side (right side of the car) and using the tool and bar the right way, you can avoid breaking the casting of the cylinder head (a common issue when injectors were in for decades ...avoid too much force applied the wrong way/in the wrong direction.
By standing on the right side of the car (on the side of the manifolds), you will be holding the socket and tool 'up' a little and pay proper attention to not push downward rather you can concentrate on the "turning " force of your tools. I usually hold the top of the bar where the extension ends and also of course the end of the bar.
This somewhat helps to avoid excessive force on the delicate injector inlet casting which in some cases broke off these engines. And that, is real trouble. I have one of those d24s... Needless to say that the engine is sitting now...
Another good advice is,
Wash the engine and blow everything absolutely clean.
Do not reuse the injector seals,
and make sure that they are positioned the right way.
Do follow torque specifications for the d24 engine.
I use a tiny tiny bit of copper paste when I do my injectors. Only on the thread and only a TINY bit, to avoid corrosion between the two kinds of metal surfaces.
Some like to use PBlaster penetrating fluid on the injectors and soak them for multiple days before attempting to remove them. I think it is a good idea if they never been taken out. Of course, get it all out before removal of the injectors.
Another good advice is I think to not disturb the hard lines as much as possible. If the injectors are stubborn, you can always play the loosen-tighten-loosen again-tighten again game a little bit until you get a better feel of them coming out more smoothly.. You want to do absolutely *everything* to preserve as much of the aluminum thread as possible
Pulling the bar up to achieve your counterclockwise turning at the injectors is safer than pushing the bar down to achieve the same counterclockwise action...so position yourself accordingly and do the same at installation at the final torque-ing, too (better doing it by pulling bar up than pushing it down). When strong action is happening , always make sure that it is happening upwards rather than in a downward direction (of the tools). --- Similarly, when you torque them back, you preferrably want to pull the bar/tool up (SAFER), rather than positioning the tool where you would have to 'push down" (more dangerous).
Most of these were random advice that came to my mind relating to your question. I am sure most of us do know about all of these "tricks".
PS.
Take care of the injector nipples. They are fragile and will deform when the wrong tool is used (I have some of those, too
wrong tools and broken injectors, too
)
Regular 27mm sockets usually do NOT work properly for removing the d24 injectors. Especially not the hex ones. Often times I had to grind away the wall thickness too, to make sure that the tool is not hurting the cyl head surface (some injectors tend to have less space behind them than others).... If you have an old socket to use, soak it, spray it clean, blow it completely clean.
I find these to be the best ones to use, quite safe, easy and most convenient. Plenty of space inside and they will not hurt the nipples where the fuel return lines go.
https://www.fcpeuro.com/products/die...IaAsSVEALw_wcB
PS 2.
Post pictures!