what injector cleaner should i use for my 79
09-06-2016, 01:05 PM
#3
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Chevron Fuel System Cleaner with Techron, about 1 tank of fuel before your scheduled oil change.
09-06-2016, 01:09 PM
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The CIS injectors do not pulse open and closed so USA 78-79 injectors spray all the time....just like a garden hose nozzle. Most any additive to the fuel MAY improve the spray pattern which only really matters much at idle speeds.
11-14-2016, 11:25 PM
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I have put in two cans of LiguiMolly for the last four months in my 1984 928s and just turn 168,000 miles. I have had my 928s for 27 years I have never put anything in my cars like this before but my 928 runs so good now it is a joy it runs so good!!! Vernon
11-15-2016, 02:11 PM
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If you are truly concerned, you'll likely want to just pull the injectors and soak them in your favorite flavor of deodorized mineral spirits to start. That will take care of most everything. If the injectors are "varnished", you can get more aggressive.
In my limited experience with CIS injection, I've decided that anything I put in that might be strong enough to get varnish and other hardened deposits out will also be strong enough to trash the delicate o-rings and the varnish/shellac used for the head on the metering unit. Most pour-in-the-tank products are too weak for that reason; they are OK for keeping stuff from plating out, but are marginal at best for getting hardened fuel deposits flushed out.
The CIS injectors are sitting in rubber grommet-like seals that are well hardened now with heat and age. Enough so that the old injectors can be tough to remove, and certainly hard enough to deserve replacement. A bit of rubber lube on the nozzles before insertion is appropriate too.
There are recommendations for specific MB V8 CIS replacement injectors that will work well. Cleaning the CIS injectors requires a lot of available flow and pressure to get a usable flow of cleaner forced through each nozzle. New replacements may be safer and a lot easier if you don't want to get set up for cleaning teh old ones.
In my dark CIS past, I had a spare fuel pump for this service, and a glass jar with holes in the lid so spray pattern could be confirmed. My little hot-rod Saab Turbo with CIS risked piston and cylinder damage of the system wasn't in top condition. Injector cleaning and testing this way was almost an annual ritual, along with replacing the little brass filters in those, the warm-up regulator and the metering unit. CIS cars need to be driven regularly to keep them happy, clean and lubricated.
In my limited experience with CIS injection, I've decided that anything I put in that might be strong enough to get varnish and other hardened deposits out will also be strong enough to trash the delicate o-rings and the varnish/shellac used for the head on the metering unit. Most pour-in-the-tank products are too weak for that reason; they are OK for keeping stuff from plating out, but are marginal at best for getting hardened fuel deposits flushed out.
The CIS injectors are sitting in rubber grommet-like seals that are well hardened now with heat and age. Enough so that the old injectors can be tough to remove, and certainly hard enough to deserve replacement. A bit of rubber lube on the nozzles before insertion is appropriate too.
There are recommendations for specific MB V8 CIS replacement injectors that will work well. Cleaning the CIS injectors requires a lot of available flow and pressure to get a usable flow of cleaner forced through each nozzle. New replacements may be safer and a lot easier if you don't want to get set up for cleaning teh old ones.
In my dark CIS past, I had a spare fuel pump for this service, and a glass jar with holes in the lid so spray pattern could be confirmed. My little hot-rod Saab Turbo with CIS risked piston and cylinder damage of the system wasn't in top condition. Injector cleaning and testing this way was almost an annual ritual, along with replacing the little brass filters in those, the warm-up regulator and the metering unit. CIS cars need to be driven regularly to keep them happy, clean and lubricated.
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11-23-2016, 09:32 PM
#9
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techron, all day long. I always saw improved performance afterwards.
The question is why? what's the need?
The question is why? what's the need?
11-24-2016, 11:07 AM
#11
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I ended up buying new Mercedes cis injectors and never looked back...
