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Cleaning injectors the low tech/budget way

Discussion in '308/328' started by climb, Jun 17, 2010.

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  1. climb

    climb F1 Rookie

    Sep 19, 2006
    4,866
    Atlantic Beach Fl
    Full Name:
    Stuart K. Hicks
    #1 climb, Jun 17, 2010
    Last edited: Jun 17, 2010
    After reading Birdman's wonderful thread on cleaning injectors with the bosch pressure tester and cleaner i came upon a post by Desire308 suggesting that the injectors could be cleaned by leaving them in the car and inserting the red tube from a can of carb/injector cleaner. Doing this limits the results as you cant see the spray pattern nor can you test the pressure values of the injectors but i really wanted to do it anyway and now i'm really glad i did.

    The most difficult part was using that short red straw that came with the can of carb spray. It doesn't give you enough length to accomodate for the obstructions ( hoses etc.) between the can and the injector. What i did was first put the straw in the injector then take the nozzle off the can of spray and attach it to the straw.. lastly put the nozzle in the the can. This allowed you to get the can and straw at the angle needed for each cylinder.

    So what happened?

    Well, like i said you can't see the spray pattern changing from stream (bad) to mist (good) but what i found is that you can HEAR it. That is on some cylinders the sound would be baffled and backpressure would allow some of the spray to creep out of the sides of the nozzle but then after a few seconds of spraying the sound changed (a great feeling btw.) and the flow would increase without the backpressure as the cleaner opened up the injector.

    So:

    To anyone not wanting to tackle the job the right way (buying Verrel's pulling tool and using the bosch pressure tester) this may work for you. I found that one injector still had a different sound than the others and i suspect it's stuck in a too low or too high condition and should be changed. I've only done one bank so far but can already feel an improvement in the throttle response (instant instead of the quarter second delay as usual) and the usual snorts and pops that i had been getting before the car warmed are gone. No word on the effect on my car's main problem (header glow and midrange sputter) as it started raining just as i took her out but i'm hopeful.

    BTW: Be very careful when putting the fuel lines back on and make sure you get them on straight. One that i put back on was on a little cockeyed and sure enough it was seeping gas so check and double and tripple check each one.

    If nothing else this would be a good idea to do once a year just to keep things clean and atomizing correctly. What really amazes me is how many cans of techron and fuel injector cleaner i've used so far in the 3k miles i've put on my car that had no effect in comparison to the direct spray technique.

    Hope this helps someone.
     
  2. Rifledriver

    Rifledriver Three Time F1 World Champ

    Apr 29, 2004
    37,100
    Cowboy Capitol of the World
    Full Name:
    Brian Crall
    #2 Rifledriver, Jun 17, 2010
    Last edited: Jun 17, 2010
    Don't bother cleaning them. Bosch never intended those to be lifetime parts, they were really designed and built cheap to be throwaways. The valve assembly does wear, they go bad. The tester is as much for testing and diagnosing bad injectors as for cleaning. At $20 each do yourself a favor and buy a set.


    Besides your method is really not valid. The most important aspect of their operation is leakage and you are not testing for that. Pattern is just not that important. With engine heat and high velocity airflow even crummy patterns work quite well.
     
  3. climb

    climb F1 Rookie

    Sep 19, 2006
    4,866
    Atlantic Beach Fl
    Full Name:
    Stuart K. Hicks
    #3 climb, Jun 17, 2010
    I know. At least i feel like this may take care of any problems related to clogged or dirty ones. After hearing the different sounds and feeling the different amounts of resistance each makes i realize they need to be changed. But for now...
     
  4. mustardfj40

    mustardfj40 Formula 3

    Jun 17, 2004
    1,142
    Northen California
    Full Name:
    Ken
    #4 mustardfj40, Jun 17, 2010
    These injectors are ones of the cheaper thing sabout a 328, replace them all while they are still affordable and you don't have to worry about them for many years. Personally, I don't like messing with gasoline in the garage cleaning these things, I have seen homes burned down while people working on their projects, ain't worth it.
     
  5. cmt6891

    cmt6891 Formula 3

    Feb 25, 2008
    1,338
    Encino, Ca
    Full Name:
    Carl T
    #5 cmt6891, Jun 17, 2010
    Not to mention the fact that the original injectors are made of steel and are prone to rust. They were never made to last 20 plus years. The new replacements are brass, a far better material for the injector. At $160 a set of 8, it is the cheapest improvement you can make.
     
  6. Iain

    Iain F1 Rookie

    Jan 21, 2005
    3,320
    UK
    #6 Iain, Jun 18, 2010
    I think its also the case that the injector seals are prone to deteriorating & leaking air which will screw things up. So after 20+ years it can't be a bad idea to change these too.

    If you are replacing injectors on a 328, just be carefull with the injector carrier - they are made of some kind of brittle plastic & ruinously expensive.

    New injectors are around $20 - or there are some jokers selling used ones on e-bay for over $100 each :D
     
  7. Iain

    Iain F1 Rookie

    Jan 21, 2005
    3,320
    UK
    #7 Iain, Jun 20, 2010
    I just ran my car today for the first time after replacing the injectors & seals. It has 37K miles on it, has always had good quality fuel & regular doses of injector cleaner once or twice a year.

    My advice to anyone wavering as to whether to do this is to just do it. I thought the thing ran well before but there is a marked difference. Its snappier and smoother & its not popping & banging on the over-run so much (which, in hindsight, may have been an injector or two not closing properly). My car had steel injectors before & now has brass ones.

    I replaced both the inner and outer seals & also used Verrels kit to replace the plastic lines (and had all the hard lines & banjo bolts etc re-plated which was surprisingly inexpensive to do.)
     
  8. phild328

    phild328 Rookie

    Aug 2, 2004
    35
    Lebanon, PA
    #8 phild328, Aug 12, 2022
    I was living with leaky injectors for years and didn't know it. I had a hot start problem. If I stopped to go in a store or something and came out 10 minutes later, it would take a lot of cranking to get it started. I had previously ruled out a leaky injected because I had used pressure gauges to measure the system and control pressures. I also had pulled the injectors (while still connect to the line) and put them in a jar to see if anything would leak out.
    Well, I went on ebay and purchased a $75 diesel injector cleaner/tester. The problem is the gauge is too high pressure. So take it out, and buy a low pressure guage at harbor freight. Mine had a weird connection and threads, so I cut that connector off the original guage, tapped it with the 1/4 ntp and put in the new guage. Works great for $80 total. What I found out was I had a bunch of leaky injecters ,4 of them, and some dirty injectors. After cleaning, the spray pattern was nice, but I had to replace 4 that couldn't be cleaned. You can google the cleaning and pressure testing, its simple. Mine leaked out right away, so that is why I didn't catch it with my previous in car test. It doesn't leak a ton of fuel, but for me, with 4 of them it added up to a flooded engine and I guess a little time to rebuild pressure.
    With the new and cleaned injectors, the hot start problem is solved. I don't really notice any power difference. With continuous injection, I guess it all averages out at the rpms we need to drive at.
    Anyway, I just thought I would share the tip on the $80 cleaner/tester, for that price it is worth having so that if you are replacing injectors, you can clean and test your old ones and know what is going on. Also, with inflation, eight injectors are getting expensive, so if you don't have to replace them, all the better.
     

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