Fuel system cleaner | Chevron Techron

Digitalchaos

Registered User
As I have posted in other threads, I have had hard starting problems with my car for sometime. When cold and when sitting for short periods after running, my engine cranks many times before actually starting, usually as long as 5 seconds. During this time and especially when warm, there is a slight smell of fuel in the air. There is also black smoke present in the exhaust during and immediately after a hot start. Because of this, and because there are no other symptoms, I am thus concluding that one or more of my injectors could be leaking fuel after shutdown.

It seems that if the injector malfunction is being caused by dissolvable deposits, a cleaner could restore proper operation. After much reading at bobistheoilguy.com, it seems like my best option could be the gasoline additive fuel system cleaner Chevron Techron concentrate. Many have reported this product to have good injector and even CC cleaning properties while being safe to nylon, plastic, rubber, and other fuel system components. I have also been informed that Chevron Techron will not foul the spark plugs as some cleaners could which as you know is important due to how hard the plugs are to change in this vehicle.

I would therefore like to ask if anyone has any significant evidence or reasons against or for the use of this product before I make my final decision. For example, our gas tanks are made out of a special polysilk substrate that could spontaniously combust in the presence of techron mixed with gasoline? :)

Thanks for any info you can provide!
 
cleaner

My SC skiped after useing the Valvoine brand.I was just doing reg mainatince Let us know how the Chevron stuff works I would like to do my SC again still not running as good as it was.
 
As an update, I have finished a tank of the Techron. While it smoothed some of the bumps in my idle, it had no impact on any of my starting problems. Therefore I can conclude that if my problem was due to dirty injectors bleeding off pressure, the Techron concentrate was unable to clean them sufficiently
 
I only use the 92 octane Chevron Techron fuel and I've never had a slow start with either of my SCs and whenever something was odd, I add a bottle of STP injector cleaner to a tank of fuel. What is the cold cranking amperage of your battery? You need 650, maybe its a little weak. Good luck
 
vancouverBC, considered electrical but the symptoms don't seem to add up. It cranks with less time when warm, and runs a little rich starting warm.

The battery is a new Interstate 1000 CC. Definately ok. Charge is ok also.. alternator is ok.

I really think its a bleedoff problem, just trying to isolate it. So far the parts in the fuel system that I am aware of which could cause this problem are FPR, injectors, clogged fuel filter (lean), slow fuel pump (lean), and if we have one a bad check valve.

Fuel in the gas indicates it can only be something which is leaking fuel into the combustion chamber after shutdown.
 
It usually takes several tanks to clean the injectors. I'm having the same problem you are and also suspect one or more of my injectors are leaking. I'll try a couple tanks of the cleaner and if that doesn't work I'll pull the injectors and send them off for cleaning.

David
 
Generally I toss in some STP FI cleaner every 5000km and have had no problems. Have you routinely used it or have just started? Cause if you're doing it for a first time it may take a few doses to clearn 'er up. But if you use it all the time, you shouldn't have any problems.
 
A lot of people on the boards are having fuel problems. Do you think it might be some thing they are adding to the gasoline due to the high price and all?
I know they use a winter mix in in the bigger cities to cut down on polution but could they be adding something we don`t know about?
 
Ref Fi Cleaner

I Worked For Napa For About 8 Years And Have Had Alot Of Success With Their Fuel Injector Cleaner. The Name Is Macs Part #6660. There Is A Cheaper One Also, Part#6600 That Works Well But The Previous Also Cleans The Top End. I've Used It In Several Vehicles And Never Had A Disappoinment. Just Shake It Up Pretty Good.
 
NAPA has a better fuel injection cleaner made by Echlin, i belive it is part number 2-18480 but i could be wrong on that. but it's the one that come in a 2 bottle package. The techron is good also, But the thing about ANY of the Fuel injection cleaners that you pour into the tank, is that they are primarily for PREVENTIVE MAINTENANCE, not designed to cure a problem at already exists. The reason for this is that any chemicals strong enough to actually clean out a clogged injector are too harsh for the in tank fuel pump and could damage it. You have 2 options in this case..... have your injectors cleaned professionally in the car..... they disable your fuel pump and attatch a fitting directly to the schrader valve on your fuel rail, and run the car on a very high strength injector cleaner..... OR there may be a shop in your area that has an "ultrasonic" fuel injector cleaner. You have to remove the injectors, but the flow rate and spray pattern can be observed after cleaning so you KNOW they are working properly. I had this done on a firebird i had with the 5.7 TPI engine.... i think it cost about $125 for all 8 injectors but that's a fraction of the cost of replacing them.
 
I just finished a tankful of a second bottle of Techron. The only pattern I am finding to this is that my crank time has increased[i/] after adding each of the two bottles.

My car is now taking longer to crank after the second bottle than it was after the first, which was longer than before I used any.

Does this provide any clues? Could it be unrelated to the injector cleaner?

Although I wasn't anticipating anything specific, these results from the Techron were certainly unanticipated.. lol.

Thanks for your help so far..
 
Have you checked for codes. Maybe the ECT sensor is bad. The ECT sensor input is part of the cranking process.
 
cleaner?

I had this happen on my 88 Mustang GT. I ran some fuel injector cleaner in the tank and it loosened up dirt and whatever in the tank, filter and lines and clogged the injectors. Had to take it to a shop and have the injectors cleaned with Wynns where they take the fuel lines loose and the car runs off of the can of cleaner. The car had 85,000 when I got it, so there was no telling if they had ever been cleaned before.

I too am having a slow starting problem with mine that comes and goes. Hope somebody can figure this out because we might all have a similar problem.


David
 
Last edited:
the only time i ver had injector trouble was on my turbo coupe i stopped and bought stp gas treatment it fixed my miss and black smoke in less than a mile i believed in it ever since , if you smell gas could it be an o ring on an injector ?
 
rlong, good question.. and I don't have an answer. I do know that I now have two different vehicles with nearly the same problem, only the SC isn't so bad yet and starts better when warm. :eek:
 
If anyone has any further ideas, please post them.

Most recently, I have noticed that cycling the ignition a few times before startup seems to reduce crank time noticeably.
 
Back
Top