how do you clean your injectors?

[Airborne Ranger]

Working on getting my truck winterized, I got the detailing part of it squared away now it's time to focus on my mechanicals. I have a 2.5L dual plug 4banger. I would like to run something through my truck, because it has a hesitation problem. I would like to try to run something to help clean the injectors. What remedies or what's your plan of attack when you clean your injectors??? tks,,,91

[Lowejackson]

Hesitation problems could be caused by a number of things, however, in answer to your question, there are several options available to you.

The quickest way is to pour some cleaner into the gas tank and drive in the normal way to clean the injectors

IMO, the best way is to have them clean ultrasonically. They are removed from the engine and cleaned. This also allows the flow patterns to be checked along with flow rates.

With the in the tank type cleaners, it is impossible to know if they have successfully cleaned the injectors but they do clean to a degree. The most professional way is via ultrasonics.

[Scottwax]

You local lube goons can also do a complete upper end, throttle body and injector cleaning for around $50 or so. I had always thought just using a fuel injection cleaner would prevent deposits, but after I got the service done to my car, I am a believer-they cleaned out my throttle body and trickled a cleaner through a vacuum line into the intake manifold for about 15 minutes or so while the engine ran at about 1200 rpm and for about half that time, there was noticable black smoke coming out of the tail pipe. I guess (at that time) almost a quarter of a million miles of driving left a lot of deposits in the combustion chamber and on the valves. I immediately noticed better throttle response and my car felt noticably quicker on acceleration....enough of a difference that when I gave my brother a ride he asked what I had done to the engine. I also picked up about 1 mpg in city driving.

I'll continue to get this service done about every 15-20,000 miles and I've also switched to Chevron gas which also seems to help. I was having some minor bucking and surging issues this summer and changing the fuel filter helped that and my mechanic recommended I switch to Chevron gas because it has a higher concentration of cleaners in it that the cheapie off brand gases don't.

[Dave N]

I use Chevron Techron injector cleaner every time I change my oil (7500 miles). It costs about $7 per bottle, but I've heard more than one place that it's one of the best "dump-in-the-tank" cleaners.

I've also heard that Sea Foam injector cleaner is good. This is the type that you connect to a vacuum line on your intake manifold (like Scottwax was talking about), and it makes your car smoke like a Cheech and Chong movie. I've never used it, so I can't comment on effectiveness.

It's also a good idea to clean your throttle body every 20-30,000 miles.

[Lost Pup]

I would use the complete Injector/TB clean process from a local shop first and then use an in-tank product as a PM. Normally we change the fuel filter when the complete injector/TB job is done. The customers usually notice the "crispness" return when the full clean is done both at idle and under load.
Many times cars pull a code when they come in and they are just not maintained properly until they become undriveable and we do a rather complete clean-up and repair on them. Injectors/TB could be just one of the problems.

[rjstaaf]

Originally posted by Dave N
I use Chevron Techron injector cleaner every time I change my oil (7500 miles). It costs about $7 per bottle, but I've heard more than one place that it's one of the best "dump-in-the-tank" cleaners.

Ditto

[rjstaaf]

Originally posted by F-150_91
Working on getting my truck winterized, I got the detailing part of it squared away now it's time to focus on my mechanicals. I have a 2.5L dual plug 4banger. I would like to run something through my truck, because it has a hesitation problem. I would like to try to run something to help clean the injectors. What remedies or what's your plan of attack when you clean your injectors??? tks,,,91

In addition to the injectors you might also want to look at the fuel filter.

[Lowejackson]

Hesitation could also be caused by faulty AFM, various sensors such as the water temp, throttle switch, lambda, partial air leak on the intake system etc etc. Best thing is to get it checked out by a garage.

[Sci-Fi]

Normally, a shop would either remove the injectors and have them ultrasound cleaned or disconnect the fuel line (and gas pump) and connect/run a can of compressed concentrated injector cleaner through while the engine is running at a set rpm.

SciGuyJim did some tests. Here is his post:

These tests were done by me to help determine the best products:

Background about tests:

As a worst case sample of material which might be found in gasoline I used ordinary tar. The brown deposits we find coating carburators, and which collects in fuel injectors and on intake valves, are the highest boiling components in gasoline. They are tar-like materials which distilled along with the lighter gasoline. The best solvent I've ever seen for these was methylene chloride, but it's expensive and I'm sure it's being phased out to protect our ozone layer. In any case, if you used it on a modern car the chlorine freed during combustion would corrode the oxygen sensor. Amoco advertises a cleaner gasoline and I'm sure it's because they've reduced these tar-like compounds. All gas these days contains at least a little detergent of some sort to help keep these deposits from building up too much.

Dimethylformamide is listed in the literature as being a good engine cleaner and is "especially good at dissolving carbonaceous deposits". I haven't used this myself because it is a bit too toxic. Instead I used N-methyl pyrrolidone, which is also good.

For my tests, I tried to use a wide variety of products, well known and unknown, expensive and cheap, and also some pure solvents in order to represent a good cross section of products on the market. Note, carbon itself (such as soot and other thermally decomposed material) is not soluble in ANY solvent but solvents like dimethylformamide and N-methyl pyrrolidone do a good job of breaking up clumps and dispersing the fine particles to release the heavy tarry materials trapped within them. However, some of these solvents are too harsh to use freely in the fuel system. (Someone in one of these forums told me that when the auto industry looks for good cleaners, they mostly look for solvents that will not attack the plastic and rubber parts in the system.)

Most cleaners (the safer & slightly less effective ones) usually have common solvents in them like toluene, alcohol, acetone or methyl ethyl ketone, and naphtha. If you want to use these to clean your system, you can get more for your money by buying the pure solvents at a hardware store and mixing them yourself. I have never had a problem adding toluene, acetone, alcohol, or naphtha to my gas tank in quantities up to one quart per 16 gallons.

Most of the straight solvents I used are at least as flammable as gasoline so be careful if you use them. The alcohol used was pure, 100% isopropyl alcohol. This has no water in it, it is not the same as "rubbing alcohol".

These test results are as fairly and accurately done as I could manage with the equipment I had available, and the other data presented is also accurate to my knowledge. Your car may have different plastics in it than mine does so if you choose to make your own cleaner, do it at your own risk.

TEST RESULTS

RELATIVE EFFICIENCIES AT WHICH VARIOUS CLEANERS WILL DISSOLVE HIGH BOILING RESIDUES FROM GASOLINE AND CARBONACEOUS DEPOSITS FOUND IN USED MOTOR OIL, (10=BEST):

· 10 Gunk Gas Treatment
· 10 Toluene (a common ingredient)
· 9 Castrol Syntec Power System
· 8 Duralube Fuel System Cleaner
· 7 Gunk Fuel Injector Cleaner
· 6 Redline SI-1
· 5 Gunk Air Intake Cleaner
· 4 Naphtha (a common ingredient)
· 4 STP Fuel System Cleaner
· 4 Seafoam Motor Tuneup
· 4 Trak Fuel Injector Cleaner
· 4 STP Intake Valve Cleaner
· 4 CD-2 Emission Cure
· 4 Prolong Fuel System Treatment
· 3 CD-2 Fuel Injector Cleaner
· 3 Techron Concentrate
· 0.5 Butyl Cellosolve (a COMMONLY used "AUTO INDUSTRY DETERGENT" for oil and grease)

THE FOLLOWING CLEANERS DO NOT HURT NYLON (LISTED RANDOMLY).
(The letters in parentheses indicate how well they dissolved the material from used oil, A=best.):

· Toluene (A)
· 2-Phenoxyethanol (A)
· Duralube Fuel System Treatment (B)
· B-12 Chemtool (B)
· Trak Fuel Injector Cleaner (C)
· Techron Concentrate (D)
· STP Intake Valve Cleaner (E)
· Seafoam Motor Tuneup
· CD-2 Emission Cure
· Prolong Fuel System Treatment
· Aromatic distillates
· Naphtha
· Butyl cellosolve
· Acetone

THE FOLLOWING CLEANERS WILL DECOMPOSE THE NYLON SOCK IN THE FUEL TANK. Listed in order of increasing severity:

· STP Fuel System Treatment
· CD-2 Fuel Injector Cleaner
· Gunk Fuel Injector Cleaner
· Castrol Syntec Power System
· Redline SI-1
· Gunk Gas Treatment
· Monoethanolamine
(The monoethanolamine is the worst here. It turns nylon black on contact. It is significant to note here that the "best" "detergents" in use today are similar, strongly alkaline organic solvents). Another use for the current bunch of organic amine "detergents" is cleaning deposits out of cylinders, so I hear.

I hope this takes the guesswork out of choosing good products.

[SuperBuick]

ScottWax, the procedure you are talking about is actually a very easy, and cheap DIY procedure that I do on my car(s) every year. You can go to any GM dealer and buy a BOTTLE (not the spray) of "GM Top Engine Cleaner". You disconnect a vaccum line (i.e. cruise control), and use the included straw (inserted into vac line) to suck up the liquid contents. While doing this, the engine will try to stall, so have your hand on the throttle body to prevent stalling, at the very end of the bottle, being careful not to suck up any air, you let the last of the liquid stall the engine. Let sit for about 15 minutes. Start the car (may need to give it some gas to get it started), and then go drive like hell for a few minutes while watching white smoke pour out of your tailpipe. All that white smoke is the carbon and gunk buildup on your valves, intake, etc.

-Tommy

[Lowejackson]

Just out of interest, why would carbon become white

[Scottwax]

Originally posted by SuperBuick
ScottWax, the procedure you are talking about is actually a very easy, and cheap DIY procedure that I do on my car(s) every year. You can go to any GM dealer and buy a BOTTLE (not the spray) of "GM Top Engine Cleaner". You disconnect a vaccum line (i.e. cruise control), and use the included straw (inserted into vac line) to suck up the liquid contents. While doing this, the engine will try to stall, so have your hand on the throttle body to prevent stalling, at the very end of the bottle, being careful not to suck up any air, you let the last of the liquid stall the engine. Let sit for about 15 minutes. Start the car (may need to give it some gas to get it started), and then go drive like hell for a few minutes while watching white smoke pour out of your tailpipe. All that white smoke is the carbon and gunk buildup on your valves, intake, etc.

-Tommy

Yeah, I know I can do it myself, but I had just failed an emissions test (high on NOx), so I wanted it done then and there and ran through again for free. I can get the pro kits from my Honda mechanic, but I'll bet the GM product is cheaper so I may go that route next time.


Lost Pup-I definitely noticed a difference in my car when I had that procedure done. I had always used a F/I cleaner about every 5000 miles and figured that was enough. Boy was I wrong!