Cleaning fuel injectors w/Techron?

[donbecker1234]

Can I just soak my injectors in a can full of Techron?

To add, this is a 78/79 930 engine, with the stock CIS Bosch injectors.

Everything seemed to work fine, was thinking I could soak them in Techron and maybe it might clean them a bit while I have the car apart.

[boyt911sc]

Don,

Send your CIS injectors to me and I will test run them with fuel injector cleaner for FREE. This is my home-made CIS flow test gizmo. I was doing a flow test for a CSV for another PP member a few weeks ago.







BTW, thank you for the links you sent me tonight. This is the least I could do for your help. PM sent.

Tony

[7783911]

Dies the techron have the advantage of flushing the entire fuel system or does it really target only the injectors? Curios because i have a bottle but havnt used because my injectors were pulled and ultrasonically cleaned/tested by a company in Houston specializing in injector including our old ones

Holding onto the techron for future use

[don gilbert]

I dont think there is anything better than techron. Best stuff ever for a CIS engine. I use it once a yr on all my vehicles, my toyota I bought new is nearing 500k. First time you use it on an oldie, change out the fuel filter, it will peel of all the varnish on an old tank and really slow down your flow.

[Lyle O]

I have been a believer in Techron for a long time. I run a bottle through the system at least once per year, and do a traditional "Italian Tune up". When I rebuilt my engine some years ago, I found the pistons and valves with very little carbon build-up at all. When I had my injectors cleaned (110,000 miles on them), they were not in too bad of a condition either (according to the flow data that the cleaning company provided). Everything stays very clean.
Interestingly, I like to buy it at Costco. For a while. the bottle said "Fuel Injector Cleaner". Then, it switched to "Fuel System Cleaner". I don't know if the formulas are different, but I use it anyhow with the same success.

[spuggy]

Originally Posted by donbecker1234

Can I just soak my injectors in a can full of Techron?

To add, this is a 78/79 930 engine, with the stock CIS Bosch injectors.

Everything seemed to work fine, was thinking I could soak them in Techron and maybe it might clean them a bit while I have the car apart.

Note that all the cars mentioned in the bulletin you posted are EFI. They don't have CIS injectors like your 930.

That said, I only ever willingly buy Chevron Premium; Techron is included in the additive pack already mixed into the fuel - and many anecdotes about this fuel blend - (including auto companies trucking it into the state where they do auto testing - not sold there- for the measurably better results). And how, when Fed requirements for fuel got raised some time back, only the formulation of Chevron Premium didn't change at all - as it already met/exceeded all the requirements.

But proprietary formulations are secret, subject to hyperbole, smoke 'n' mirrors - plus likely change whenever it suits somebody (probably not you), with no notification.

I would personally prefer to run a low level of pre-mixed injector cleaner in the fuel through the motor all the time, versus dumping additives in. So that's what I do, by stopping at Chevron stations and selecting Premium.

CIS injectors are impossible to dismantle and clean. One big issues is that they have an internal screen - once that is blocked, it's usually game over.

That said, you could try holding the pintle open with wire, ultrasonic cleaning them for as long as it amuses you (2 weeks will even remove decades-old baked-on varnish/fuel stains) and periodically back-flushing against the screen with a solvent of your choice; can't hurt.

The test for CIS injectors is crack pressure and spray pattern. If both are "good" (and, ideally, matched across the set) and they seal (don't leak/dribble), nothing more to do.

It's been said that there's a certain amount of variance (5%, I seem to recall as the allowable spec) between brand-new injectors out of the box.

Some flow-match CIS injectors, selecting the higher-rated ones for the cylinders that tend to run lean/hotter in a 930 and/or twiddle fuel distributor ports to match or adjust output.

[7783911]

so i should expect the fuel filter to capture "crap" after running a tank full

[GaryR]

Originally Posted by boyt911sc

Don,

Send your CIS injectors to me and I will test run them with fuel injector cleaner for FREE.

Tony

Now THAT is a great/generous offer Tony!
Don, it's a no-brainer as Tony will make sure the flow and pattern is correct also, only way to go!

[darrin]

Originally Posted by 7783911

so i should expect the fuel filter to capture "crap" after running a tank full

it should, as long as it's not a "crap ton" -- also keep in mind that Techron's a solvent that will also likely squeeze by piston rings and (ever so slightly) dilute oil. I like to time my Techron additions to add to the tank (or so) before an oil change to minimize that effect,

[boyt911sc]

Originally Posted by GaryR

Now THAT is a great/generous offer Tony!
Don, it's a no-brainer as Tony will make sure the flow and pattern is correct also, only way to go!

Gary,

I’ve been trying get hold of a Technical Bulletin for 930 engine for a while. And Don provided me a link that has all the information I need for my work. The information from this source is priceless. He even directed me to the exact page where to find the section.

A couple of hours after receiving several websites from him, I saw his post about CIS injector cleaning. The least I could do to express my gratitude is offer my home brew CIS bench tester. People have assisted and helped in so many ways and giving back something to the community makes us stronger and united. Give and take.

Stay safe and healthy. We will back outdoor soon.

Tony

[donbecker1234]

Originally Posted by boyt911sc

Gary,

I’ve been trying get hold of a Technical Bulletin for 930 engine for a while. And Don provided me a link that has all the information I need for my work. The information from this source is priceless. He even directed me to the exact page where to find the section.

A couple of hours after receiving several websites from him, I saw his post about CIS injector cleaning. The least I could do to express my gratitude is offer my home brew CIS bench tester. People have assisted and helped in so many ways and giving back something to the community makes us stronger and united. Give and take.

Stay safe and healthy. We will back outdoor soon.

Tony

Hi Tony,

Thanks for the offer, PM and email sent.

[donbecker1234]

Originally Posted by Lyle O

I have been a believer in Techron for a long time. I run a bottle through the system at least once per year, and do a traditional "Italian Tune up". When I rebuilt my engine some years ago, I found the pistons and valves with very little carbon build-up at all. When I had my injectors cleaned (110,000 miles on them), they were not in too bad of a condition either (according to the flow data that the cleaning company provided). Everything stays very clean.
Interestingly, I like to buy it at Costco. For a while. the bottle said "Fuel Injector Cleaner". Then, it switched to "Fuel System Cleaner". I don't know if the formulas are different, but I use it anyhow with the same success.

Hi Lyle,

I read somewhere that the Costco versus may not be as concentrated as from other sources but I have not yet confirmed.

[pkabush]

It’s not hard to test the spray pattern for CIS injectors. Just take em out put em in individual bottles
Activate the fuel pump and set your timer. I forget the flow amount vs time but google is your friend. Or someone with a better memory than me will chime in.
I’ve had good success cleaning them using JFairmans back flow method.

[E Sully]

It's important to do both directions. I have back flushed mine using the JFairman method. Only way to clean internal screen.
CIS Injector Cleaning

[boyt911sc]

Don,

Some information for your fuel injectors cleaning and testing:
These are the tabulated test results: Initial/Final (before/after)
Fuel injector—————Opening press.** ————Spray Pattern**————Flow Rates**
#1——————————36 psi./36 psi.——————Fair/Good*—————— 33 ml/34 ml*
#2——————————36 psi./36 psi.——————Poor/Good*——————31 ml/35 ml*
#3——————————36 psi./36 psi.——————Poor/Good*——————32 ml/36 ml*
#4——————————36 psi./36 psi.——————Fair/Good*——————-33 ml/34 ml*
#5——————————40 psi./36 psi.*—————-Fair/Good*——————-34 ml/35 ml*
#6——————————36 psi./36 psi.——————Poor/Good*——————35 ml/36 ml*
NOTE:
* Change or different test result.
** Average for 3 different test run.

The difference before/after for the opening pressures and flow rates are not that significant compared to the results in the flow mist-like patterns for the fuel injectors. There was a dramatic improvement in all of the spray pattern characteristics of the injectors as you perform the flow tests.

The back-flush procedure contributes a lot to the improvement of the spray patterns. A 12-oz. Techron (concentrated) was added to a gallon of gasoline as the cleaning solution for this work.








You might not recognize them. I just cleaned and polished your injectors before packing them.


Tony

[donbecker1234]

Tony,

Thanks so much for doing this, I really appreciate it.

I hope the case of Techron I sent contributes to many more successful tests & cleanings.

Is there a spec you use to determine what is a good range for injector flow rates, or to put it another way, when one should be replaced?

I sent my cold start injector as well, would love to hear if that checked out as well.

[boyt911sc]

Don,

The CSV was included in the package I mailed to you. It took me a few seconds to test the CSV. Unlike the fuel injectors, it takes patience and commitment to do an evaluation. The “flow rate” is a relative number. I used a specific time (30 seconds) and a fix setting on the fuel distributor and collect data from 3 different trials and average it. This is a controlled experiment or test that I have been doing for years.

The other set of injectors that I ran after yours had much higher opening pressures than yours and at different pressures. Your fuel injectors have very uniform opening or cracking pressure compared to my old injectors.

And thank you for the $25 I found in the box with the injectors and CSV. The shipping cost was only $7. When you store your fuel injectors for a long time, use kerosene or mineral spirit not gasoline. Gasoline is not a stable solvent and will form a varnish film on your injector if kept stagnant for many months.

Tony

[BER]

Techron is a great product and have been using it in my 911's for years. Currently there are six Techron products available. See this link:

https://www.chevronlubricants.com/en_us/home/learning/about-our-brands/techron.html?src-tab=learning

The most common Techron product that I see in auto parts stores and at my local Costco is the Techron Complete Fuel System Cleaner. I use this cleaner in my 2012 Carrera S with Direct Fuel Injection. If you read the PDS for this product, it is specifically recommended for DFI vehicles.

The product I use in my 1984 911 is the Techron Fuel Injector Cleaner. The Fuel Injector Cleaner costs a bit more than the Fuel System Cleaner and is a bit harder to find. I usually end up buying it from Amazon. It has done a fantastic job of helping keep my 3.2 liter engine running strong.

Like others have said, I usually add a 20 oz. bottle of the Fuel Injector Cleaner to my 911's fuel tank approximately 500 miles before an oil change. Never have encountered any problems with my fuel filter; I normally change it every 10k miles anyway.

[Sajan]

So for a 87 carrera, what should I use?

Techron Complete Fuel System Cleaner (concentrate) (recommended every 3000 miles)
Techron Fuel Injector Cleaner (recommended every 1000 miles)

or
BG 44K Fuel System Cleaner

I have two bottles of the Techron Complete at the house I bought in 2018. Oil change was 2000 miles ago in November.

[Ctopher]

You want this, the Techron concentrate plus Complete Fuel System Cleaner.



This is the concentrate that is to be added to a 20gal full tank. I usually add it to tank on the way to a fill up before a long drive or trip.


CTopher