Been having issues with starting and would like to either try cleaning the injectors myself or pay to have it done. I have seen video and heard of a method where you hookup some kind of IV drip to the fuel rails and run this 'stuff' till it runs out. What are your guys experiances? And if I try it myself how and where do I get the kit etc?
Thanks

 

it sounds familiar i think ive seen it on youtube. try looking for fuel injection cleaning there..

 

almost easier and not that expensive to buy another set.

 

Check out harbor freight. They sell an injector cleaning tool that is very reasonably priced.

I have had the best luck using GM's Top Engine cleaner. Yeah I know some may not want to hear that, but the stuff works. Just make sure you read the can very carefully and don't over mix it because the stuff is very strong full strength.

Also you should consider capping the fuel rail off or make very sure you keep the pressure below the regulated pressure. Otherwise you will push the cleaner past the regulator and back to the tank.

Finally a word of caution. The chemical in injector cleaner eats carbon. We are a carbon based life form so it doesn't mix well with us. Be very careful not to get any in your eyes. I saw this happen to a coworker. Even though it was flushed out quickly it still did a large amount of damage to his eye.

 

You can make an injector cleaner yourself, and there are many ways to do this, and here is the easiest way to do it (and the first way I did this):

This method requires a basic PWM circuit and driver which will pulse the injectors on and off just the way your car does. Here is one of many, many schematics:

DPRG: A Simple PWM Circuit Based on the 555 Timer



The above schematic generates a 144hz pulse frequency and the variable resistor adjusts from 5% pulse width to 95% pulse width. The mosfet in the schematic can drive four high impedance injectors wired in parallel no problem and if you want to drive eight just solder two mosfets in parallel in place of the one in the schematic.

One of cleaning injectors (junkyard solution) is to build the above circuit or something similar, and drive four injectors attached to an ordinary 4 cylinder fuel rail you get from the junkyard. When you take the fuel rail, also snip off the injector harness and wire all the plugs in parallel where you cut it and solder them in place of the "M1" motor in the above schematic.

The mechanical bits are easy - stick the injectors into the fuel rail and insert the other end into a piece of metal you drilled out to match the injector nozzles (spaced the same as the fuel rail). Once the injector are in, put two zip ties around the fuel rail and the lower plate you made. Use an in-tank fuel pump from any vehicle you can find (GM cars are particularly easy to remove from inside the trunk without special tools or having to drop the fuel tank) and toss it into a metal bucket full of mineral spirits. Apply power to the pump to pressurize the rail, then power the 555 PWM circuit above, and make sure the injectors are over the same bucket you're sucking the mineral spirits out of. Let it run for a while and your injectors are clean.

The other benefit of a circuit like this is to purchase a bunch of calibrated beakers - the kind that indicate milliliters or some other measurement of volume. Place one under each injector, then repeat the above experiment except you stop the 555 timer circuit after 1 minute. You then record how many milliliters of fuel in each beaker, and now you know how close the injectors flow is as compared to each other. If you have a pile of unsorted injectors, you can easily repeat this over and over until you have a set of four, six or eight (depending what you need) that flow very similarly.

Nowadays I use something I made that's much more compact and less "fiddly" but the above method works very well and should get you started.

While naturally aspirated engines can tolerate slightly mismatched injectors, high performance forced induction engines need closer injector matching in my opinion, which is why I built this rig in the first place. Having the ability to clean them with mineral spirits was actually a secondary benefit for me.

Enjoy!

 

I have had very good luck with 3M injector cleaner hooked to the fuel manifold.
Make sure you unhook the vacuum hose to the FPR and and plug the hose.
Also remove the fuel pump relay and hold the pressure below 40 psi on an 8 and 55 on a six.
Takes about 15 minutes before the can runs out of cleaner.
The below does not look like my gauge and regulator but it takes the same can and works the same way.
I also use it for a fuel pressure gauge when not cleaning injectors.





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Thanks all, very good info.

 

I too bought new injectors a few years ago when mine were in bad shape.

I wonder what cleaning method is the best.

Does anyone use the Techron stuff?

 

I tried the Techron stuff (still have a container or two of it) but did not see any difference in how the my truck ran so then I put the 3M cleaner on it and made a big difference.

 

I was more referring to using the Techron as maintanance to prevent the injectors etc from getting dirty.

I may try the 3M. Where is a good place to buy it?

Has anyone heard of BG or GB I think its called.

 

The set I use is a NAPA brand and I use the screw-on 3M cans with it.
I also have the type set up you use an air hose with after you poor the cleaner into its container but I like the 3M better.
Both types screw onto the fuel rail after you disable the fuel pumps and FPR. Then you adjust the regulator to keep it about 35-40 psi for an v-8 while the engine is running.
The name of the air hose type is BG.

 

the one i used is called the berryman b-12 chemtool fuel treatment. you pour it in the gas tank. i used it on my truck and liked it. just avoid breathing the fumes. its strong.

 

So, if I were to shop around for a new set of injectors what would I expect to pay?

 

look on ebay.