jimathan
Wednesday 9th July 2008, 15:53
Wish I found this sooner!
Major breakthrough. Misfires & Injectors.
Hi everyone. Today while I was cleaning some injectors I made what I consider to be a major breakthrough. They were in the larger of the two ultrasonic cleaners going through the final stage of cleaning. This cleaner has a capacity of 7 gallons and is equipped with two, one kilowatt heaters, and eight, one hundred Watt ultrasonic transducers. I normally run the temperature at around 50 or 60 degrees centigrade. This is enough to get the job done efficiently without wasting money unnecessarily on electric bills. I had used it last night to clean a very dirty alternator at high temperature to remove some stubborn dirt. Today, whilst doing the injectors, I had inadvertently left the stat set at 95 degrees c.
I left them doing their stuff and went for a cuppa. When I came back about an hour later, the water was steaming away nicely, all the injectors were pulsing as they should, but only four of the five were pumping cleaning fluid out. Shock horror! What is going on I thought. Well I lifted out the one that wasn’t pumping to make sure it was connected properly. It was. I could feel it pulsing but there was nothing coming out the end! So im stood there holding it for a moment scratching my head, as you do, and bu**er me it stars working again!
I thought this is strange; it’s not a bad connection because it’s pulsing away happily. Anyway I put it back in the tank and guess what? It stopped spraying again!
Now 95 degrees may sound very hot, but engines run hotter than this. My fans on the car radiator come on at 95c and go off at around 87c. I have recorder temperatures under my bonnet with an infrared thermometer of over 105c.
Clearly, there is an issue when the temperature gets up high.
Now this isn’t the first time this has happened. I had one injector from my spare set do the same thing about four months ago. At the time I didn’t think anything of it and I just put it down to a bad contact as it only did it for a moment. I had replaced the injectors in my car with a spare set while I cleaned the originals. It ran realy well with the spare set in, much better than before. Now I did have a misfire around that time, but I also changed the plugs and thought that it was the plugs that sorted it. Time to dig out my other set to put back in the cleaner. In they went and all was well for about ten minutes then one stopped spraying. Took it back out and off it went again!
Ok, so I finish off the injectors I was doing for someone and text him to tell him what had happened. He replied by saying “that will probably explain the fault code”.
Clearly there was a problem with these injectors that would have gone unnoticed if they had not been subjected to high temperature while undergoing cleaning.
Does anyone have an intermittent misfire that seems to be worse when the engine gets hot? Does it disappear when it cools down? Does it misfire on the restart after it has been run and then parked up for ten minutes? (That would be heat soak). No airflow under bonnet while parked, heat rising into the manifold and injectors.
This is exactly what my car was doing. Incidentally, I put the other plugs back in this afternoon and there is no misfire from them. It was the injectors!
I do not normally run the cleaning tank at this high temperature while cleaning injectors because of the extra cost of heating such a large quantity of water. (The heaters are internal, high up on the sides so I have to fill it)
Having said that, if someone is sending their injectors for cleaning, and they know they have a problem with a misfire, I would be prepared to run the tank at 95c to highlight any temperature related problems for a small additional fee to cover the additional expense, but only if requested. Under normal circumstances I don’t think this is necessary, But if you are having problems I would definitely recommend it. Sorry it is such a long post but I think it was worth it don’t you?
Jim
Major breakthrough. Misfires & Injectors.
Hi everyone. Today while I was cleaning some injectors I made what I consider to be a major breakthrough. They were in the larger of the two ultrasonic cleaners going through the final stage of cleaning. This cleaner has a capacity of 7 gallons and is equipped with two, one kilowatt heaters, and eight, one hundred Watt ultrasonic transducers. I normally run the temperature at around 50 or 60 degrees centigrade. This is enough to get the job done efficiently without wasting money unnecessarily on electric bills. I had used it last night to clean a very dirty alternator at high temperature to remove some stubborn dirt. Today, whilst doing the injectors, I had inadvertently left the stat set at 95 degrees c.
I left them doing their stuff and went for a cuppa. When I came back about an hour later, the water was steaming away nicely, all the injectors were pulsing as they should, but only four of the five were pumping cleaning fluid out. Shock horror! What is going on I thought. Well I lifted out the one that wasn’t pumping to make sure it was connected properly. It was. I could feel it pulsing but there was nothing coming out the end! So im stood there holding it for a moment scratching my head, as you do, and bu**er me it stars working again!
I thought this is strange; it’s not a bad connection because it’s pulsing away happily. Anyway I put it back in the tank and guess what? It stopped spraying again!
Now 95 degrees may sound very hot, but engines run hotter than this. My fans on the car radiator come on at 95c and go off at around 87c. I have recorder temperatures under my bonnet with an infrared thermometer of over 105c.
Clearly, there is an issue when the temperature gets up high.
Now this isn’t the first time this has happened. I had one injector from my spare set do the same thing about four months ago. At the time I didn’t think anything of it and I just put it down to a bad contact as it only did it for a moment. I had replaced the injectors in my car with a spare set while I cleaned the originals. It ran realy well with the spare set in, much better than before. Now I did have a misfire around that time, but I also changed the plugs and thought that it was the plugs that sorted it. Time to dig out my other set to put back in the cleaner. In they went and all was well for about ten minutes then one stopped spraying. Took it back out and off it went again!
Ok, so I finish off the injectors I was doing for someone and text him to tell him what had happened. He replied by saying “that will probably explain the fault code”.
Clearly there was a problem with these injectors that would have gone unnoticed if they had not been subjected to high temperature while undergoing cleaning.
Does anyone have an intermittent misfire that seems to be worse when the engine gets hot? Does it disappear when it cools down? Does it misfire on the restart after it has been run and then parked up for ten minutes? (That would be heat soak). No airflow under bonnet while parked, heat rising into the manifold and injectors.
This is exactly what my car was doing. Incidentally, I put the other plugs back in this afternoon and there is no misfire from them. It was the injectors!
I do not normally run the cleaning tank at this high temperature while cleaning injectors because of the extra cost of heating such a large quantity of water. (The heaters are internal, high up on the sides so I have to fill it)
Having said that, if someone is sending their injectors for cleaning, and they know they have a problem with a misfire, I would be prepared to run the tank at 95c to highlight any temperature related problems for a small additional fee to cover the additional expense, but only if requested. Under normal circumstances I don’t think this is necessary, But if you are having problems I would definitely recommend it. Sorry it is such a long post but I think it was worth it don’t you?
Jim