DIY injector cleaning (Having a go)
Discussion
I was changing the o-rings on the injectors the other day due to a leak and it seemed like a good idea to have the injectors cleaned. However, I thought that at £15 + VAT for each injector on the V8S to be cleaned was a bit steep, especially if i had not already identified them as problematic. With this in mind I though I would have a go cleaning them at work using the equipment laying around. Here is what I did.
Injector cleaning
The injectors were prised from the fuel rail and inlet manifold. O-rings were removed and the injectors given a preliminary wipe with some thinners to remove the worst of the oil from their outer surfaces.
Each injector was immersed as far as possible without the electrical connection becoming wet in a sonic bath. The bath was filled with surfactant (non-ionic) DECON-90 ca. 5% solution. Using a pipette the inlets of the injectors were filled with uncontaminated DECON-90 solution.
The action DECON-90 solution / sonic bath slowly removes deposits on the injector. This was observed as white plumes of deposit / surfactant in the clear DECON solution. Some people may be tempted to flush forward, or reverse at this point. I preferred not to try and move the contaminants through the injector in either direction forcefully. With a transparent hose connected to the inlet supplying clean solution you can clearly see the milky deposits rising up if left for a while. The hose can be disconnected and the deposits flushed away. It can then be reconnected and the injector back-flushed.
After about 20 min in the bath the deposits appeared to have been removed. The solution was changed and the injector connected up to a pump supplying ca. 2 bar of DECON-90 solution connected using a rubber hose. The solenoid was actuated using a control source of 12V / 350 mA, switching was manual. (I have seen 3 to 300 Hz suggested).
The pump was used to drive the cleaning solution through the injector in the sonic bath, switching as quickly as manual operation would allow. This was continued until 300 ml of solution had passed through the injector.
Each injector was then tested for spray pattern by actuating the injector above the bath.
It would have been nice at this point to check the flow rate of each injector, but my pump was not really up to supplying high pressure over a long duration with any consistency. Using a dedicated car fuel pump and regulator would have been better in this respect.
After passing this test the injectors were flushed through with methanol and dried using compressed nitrogen flow through (with injector open).
At this point the injectors look much cleaner and appear to flow well with good patterns. I will let you know how the on-car performance goes.
I hope that encourages a few people to have a go. :)
Z
Injector cleaning
The injectors were prised from the fuel rail and inlet manifold. O-rings were removed and the injectors given a preliminary wipe with some thinners to remove the worst of the oil from their outer surfaces.
Each injector was immersed as far as possible without the electrical connection becoming wet in a sonic bath. The bath was filled with surfactant (non-ionic) DECON-90 ca. 5% solution. Using a pipette the inlets of the injectors were filled with uncontaminated DECON-90 solution.
The action DECON-90 solution / sonic bath slowly removes deposits on the injector. This was observed as white plumes of deposit / surfactant in the clear DECON solution. Some people may be tempted to flush forward, or reverse at this point. I preferred not to try and move the contaminants through the injector in either direction forcefully. With a transparent hose connected to the inlet supplying clean solution you can clearly see the milky deposits rising up if left for a while. The hose can be disconnected and the deposits flushed away. It can then be reconnected and the injector back-flushed.
After about 20 min in the bath the deposits appeared to have been removed. The solution was changed and the injector connected up to a pump supplying ca. 2 bar of DECON-90 solution connected using a rubber hose. The solenoid was actuated using a control source of 12V / 350 mA, switching was manual. (I have seen 3 to 300 Hz suggested).
The pump was used to drive the cleaning solution through the injector in the sonic bath, switching as quickly as manual operation would allow. This was continued until 300 ml of solution had passed through the injector.
Each injector was then tested for spray pattern by actuating the injector above the bath.
It would have been nice at this point to check the flow rate of each injector, but my pump was not really up to supplying high pressure over a long duration with any consistency. Using a dedicated car fuel pump and regulator would have been better in this respect.
After passing this test the injectors were flushed through with methanol and dried using compressed nitrogen flow through (with injector open).
At this point the injectors look much cleaner and appear to flow well with good patterns. I will let you know how the on-car performance goes.
I hope that encourages a few people to have a go. :)
Z
old64er said:
Although i applaud your "have a go" attitude, it seems like a lot of time spent for 140 quid saved?
How long did it take?
It took me about 4h in all. I did it out of interest because I enjoy it. Some people like to spend 4h in the garden, some like to spend it washing the car, most spend it watching crap TV every night. Saving £140 is like getting paid to do my hobby.
Thinking about it £140 for 4 h work after TAX is good money in my industry anyway. Z
Z,
At that amount of time it is well worth it, if you are lucky enough to have access to the sonic bath.
Us lesser mortals will gladly hand over the cash.
i do all my own servicing and repairs on the cars i have, i must have saved £1500+ on the bush changes, cam shaft replacement, door window regulator, broken driveshaft and other small issues on the griff since i purchased it a year ago.
if you can save yourself some money then by all means do it
How much would you charge a third party for this service??
At that amount of time it is well worth it, if you are lucky enough to have access to the sonic bath.
Us lesser mortals will gladly hand over the cash.
i do all my own servicing and repairs on the cars i have, i must have saved £1500+ on the bush changes, cam shaft replacement, door window regulator, broken driveshaft and other small issues on the griff since i purchased it a year ago.
if you can save yourself some money then by all means do it
How much would you charge a third party for this service??
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