Hi, my name is***** your mechanic automotive expert, and I will be happy to assist you today. In some cases, I may need more information to assist better. I apologize for any delay.
Dear customer, I am sorry for what you are going through this, I know that the repair costs are high but I have to tell you that when these problems occur, the first thing to do is replace the engine completely, there are many damage that we could not even observe. For example, one or another superficial blow to the head of the pistons from deformations at the level of the cylinders, problems in the fittings or in the rest of the hidden chamber on the block, even until the injector rests suffer defects, then all these deffects accumulate and when we believe that a job to the head and the replacements of the moving parts of the cylinder head would solve the problem but it is not like that. That is why I personally when there this blowns happens always told clients that it is best to replace at least the accesories and the head of the engine, which is the head and block assembly because it is very difficult for these engines to be working exactly as they were running before.
On the other hand, if the replacement is not possible, I see it necessary to do several jobs on the injection system, I see that the jobs done here have been on the spark plug coil and injectors but I see it necessary to replace the rail and the pump, because in the rail there may be problems regarding the regulation and fuel return, If the injection regulator is working incorrectly, there is too much fuel in the cylinders, as well as if the return is sealed or does not allow the correct passage of fuel, either for some defect, dirt or blows on the return rail, this also creates excess fuel.
Now, regarding the fault that you present in terms of the engine, it is very difficult to tell you that with the repair that you carried out the vehicle will be working correctly due to the factors that I mentioned but as in the same way due to the future of the failure, I am going to recommend you do the replacement of the rail and the fuel pump first and if this does not correct the problem you will have to locate another engine or at least cylinder head and some accesories.
Before finishing, when we have problems at the injection pulse level, that is, when the computer is working without control and there is no regulation in the fuel injection pressure system, there is an excessive injection pulse that we can take as normal but the computer may be the cause of these problems.
My goal is to give you the best advice i can based on your description, I hope to be helpful, if you have any doubt please do not hesitate to reply back.
Kind regards, Sebastian.