How to clean BOSCH CIS fuel injectors (DIY)

[@TheFreak111]

Oh man this sort of DIY stuff is exactly what I was looking for, thank you. Most of the things I find is replace this, replace that etc, without even knowing for sure what the problem is. I'm not that rich and I don't want to replace parts that might be good.

[@redpig1120]

Great video thanks

[@rsubra59]

Thanks for the video. Great tips. I tried taking out the fuel injectors from my M102 engine, but two of them are stuck. It is so hard as if the rubber is welded in. Don't know how much pressure to exert to pull them out. Worried if it will damage. My car has starting problem. It cranks and stops. Only after few cranks it starts. I learned from other youtube videos that this could be 'cold start fuel injector' problem. I have checked that too. It works, sprays fuel normally. Any other things that I should check?

[@aalabbasi]

Hi there. If it takes a while to start when cold but starts or restarts okay when warm. It's likely the fuel accumulator. This sits where the fuel pump is located. The accumulator keeps the system pressurized while the engine is off and helps dampen the pulse from the fuel pump. They do often go bad and when they do, you will experience hard starts when the engine has been off for a while due to the pressure bleeding down.

[@eri197395]

Nice info thanks

[@mrmattlakin]

very informative thanks

[@aalabbasi]

You're welcome

[@john2ndname]

Great tips and very informative!....problem with the Bosch cis system is when they sit for awhile they corrode inside! in some cases!..i use a upper cylinder lubricant in my fuel to stop any corrosion happening!..still going strong and my system is over 45 years old!

[@aalabbasi]

Yep, ethanol in fuel does not help, but also the rubber diaphragm can fail which will definitely require replacement

[@nastykev9999]

Is it possible to clean the distributor while it's still attached on the car?

[@aalabbasi]

Not really, you want to remove the injectors before you spray something through them, otherwise you could hydro lock the engine. If you're not keen on removing parts, run some fuel system cleaner through it by pouring some into the gas tank

[@6mazzini7]

Is there any specific advantage to using brake cleaner? I was considering using carb cleaner or maybe even Berryman B12 Chem-tool. Would they be any better or worse than brake cleaner?

[@aalabbasi]

Not really, I just found that brake clean has more propellent in it to pop the injectors. For the FD, it will make no difference.

[@6mazzini7]

@@aalabbasi What's FD mean?

[@aalabbasi]

@@6mazzini7 Fuel Distributor

[@rfbu]

my benz has the annoying 'almost stall' when starting warm, start & idle when cold is fine. I wonder if cleaning injectors with brake cleaner will fix it. I rather try that than replace them outright

[@aalabbasi]

They are robust (basically brass nozzles) so it's always best to clean. Your stalling issue might be a vacuum leak.

[@sarahdeshay1394]

Thanks, other videos that are titled “how to” are just a sales pitch to get you to buy a video.

[@aalabbasi]

I'm glad if you found it useful

[@Wheel_Horse]

basically basically basically