Redline SI-1 administration

[Brad_C]

G'day all,

Disclaimer up front :
I always use the [censored] cheapest fuel I can buy and just rely on routine maintenance to deal with it. Admittedly our cheapest fuel is streets above the super nasty stuff you get in the US, but it's still lacking in detergents/cleaners. It is however completely ethanol free.

I've got a port fuel injected 4 pot Volvo 740 (Bosch LH2.4 EFI). Every couple of years I pull the injectors and properly clean them on a home-made power flusher with home brewed cleaner that'd probably make the US EPA chuck me in jail on sight (it works though!). Right now we have winter coming, and I'm getting cold-start stumbles that indicate to me that the spray pattern is starting to suffer and they need cleaning. They were last done about 25,000km ago, so that's about on schedule.

Having a new young crawling infectious disease unit in the house I don't have time in the foreseeable future to do the injectors properly, I've generally had acceptable short term results with SI-1 and I have a few bottles in a box in the garage.

There's the background. Now the question. I'm off on an 900km round trip tomorrow (probably close to 2 tanks of fuel). Am I better to chuck the SI-1 in the tank and burn it out in one run, or wait until I'm back to the daily stop-start grind where it takes me a week to go through a tank for best results? I'm more concerned about injector cleaning rather than the valves right now.

I'm not interested in a discussion on the merits of the cleaner itself, extensive googling shows that almost always leads to a flamewar, nor do I want to know how to do it better with different compounds/treatments. I simply would like an experienced opinion on which option would give me best results. Short or long trip dosage?

 

[OneEyeJack]

In my case I spread out the dose as evenly as possible. I think of it as a maintenance dose, as if I were burning better over all gasoline.

I use both Red Line and Chevron because of the PEA. I also use other Red Line products and I'm very happy with their performance.

 

[Trav]

If the injectors are showing deteriorated performance already chuck the whole bottle in.
Are you pulling the filters when you clean them?

 

[mjk]

Originally Posted By: Brad_C
G'day all,


I'm not interested in a discussion on the merits of the cleaner itself, extensive googling shows that almost always leads to a flamewar, nor do I want to know how to do it better with different compounds/treatments. I simply would like an experienced opinion on which option would give me best results. Short or long trip dosage?



Good luck with this!

 

[A_Harman]

I try to plan the dosing so it stays in the tank for about a week. I put in a whole bottle and run short trips with it. I wouldn't put in a bottle just before I go on a long drive where I empty the tank in 5 hours.

 

[Boss302fan]

Originally Posted By: A_Harman
I try to plan the dosing so it stays in the tank for about a week. I put in a whole bottle and run short trips with it. I wouldn't put in a bottle just before I go on a long drive where I empty the tank in 5 hours.


Ditto...

 

[Trav]

Originally Posted By: A_Harman
I try to plan the dosing so it stays in the tank for about a week. I put in a whole bottle and run short trips with it. I wouldn't put in a bottle just before I go on a long drive where I empty the tank in 5 hours.


Thats the optimal way but it will work to some degree on a long run, when he returns then he can run the other bottle in the method you suggested, the deposits will be at least softened.

 

[HTSS_TR]

The fuel injector cleaner doesn't make any different in 1 shot long distance drive or 1-2 weeks short distance daily drive.

Fuel system cleaner likes Redline SI-1 is better to have it in the tank as long as possible, so use it after the long trip.

 

[Brad_C]

Originally Posted By: Trav
If the injectors are showing deteriorated performance already chuck the whole bottle in.
Are you pulling the filters when you clean them?


Cheers for the responses everyone. I'll do it when I get back then.

Trav, when I do the injectors I always replace the filters and O-rings. If I'm going to the trouble to pull them out I might as well spend the extra couple of bucks and go the whole hog.

Oddly enough when I got the car the injector "spray pattern" was a pretty badly misdirected stream. Once I cleaned the injectors up to get a nice pattern I noticed absolutely zero difference in fuel consumption and very little difference in driveability when warmed up. When cold however, the car runs pretty rough for about the first 2 minutes if the injectors need a clean.

 

[Trav]

Spray pattern is more important on multi valve engines where 2 individual streams are used, one for each valve. It helps with the idle quite a bit.
I have 20 micron stainless baskets if you need them. It will cost you the stamp.

 

[Brad_C]

Yeah, my theory is once the engine gets any heat in it, no matter the spray pattern it'll mostly vaporise when it hits hot metal. When it's cold then it just dribbles into the cylinder.

This 8 valve tractor engine is not particularly fussy. My older model had K-Jet injection, and when I replaced those injectors they were practically just a straight stream and that ran mostly ok. Certainly smoother with the right spray pattern, but the engines are pretty agricultural.

I appreciate the offer on the baskets. I'll have a think about that. I've just been using generic rebuild kits from flea-bay, and the filters look pretty cheap (which they are).

 

[Patman]

Originally Posted By: A_Harman
I try to plan the dosing so it stays in the tank for about a week. I put in a whole bottle and run short trips with it. I wouldn't put in a bottle just before I go on a long drive where I empty the tank in 5 hours.


Why not? That's actually the BEST time to run fuel system cleaner, as they do their best work when the engine and combustion chamber are fully up to temperature. So doing it on a long road trip is much better than doing it with a higher amount of cold starts and shorter trips. I always try to time my fuel system cleanings with long road trips.

 

[raytseng]

meh, split the difference, use half a bottle for each of the 2 tanks on your trip.

Then you got some burnt through at full operating , and some remaining as "maintenance" when you get back.

 

[ltslimjim]

Originally Posted By: Patman
Originally Posted By: A_Harman
I try to plan the dosing so it stays in the tank for about a week. I put in a whole bottle and run short trips with it. I wouldn't put in a bottle just before I go on a long drive where I empty the tank in 5 hours.


Why not? That's actually the BEST time to run fuel system cleaner, as they do their best work when the engine and combustion chamber are fully up to temperature. So doing it on a long road trip is much better than doing it with a higher amount of cold starts and shorter trips. I always try to time my fuel system cleanings with long road trips.


I'd say that approach works best for solvent-based cleaners. SI-1 and the whole PEA containing FSCs arguably do better when they have more duty cycles than a quick run through as the idea is to allow the injectors during leak down to get time with the detergent at the tips. I sort of agree it'd be better to avoid using this 'only' for short-tripping, but getting it up to temp and having several full temp cycles is plenty enough for this type of FSC, IMO.

 

[Patman]

Originally Posted By: raytseng
meh, split the difference, use half a bottle for each of the 2 tanks on your trip.

Then you got some burnt through at full operating , and some remaining as "maintenance" when you get back.


Or try to time it so that before you start the trip you run the cleaner with normal everyday driving for the first half of a full tank, and then the last half of that tank do it with all highway driving. I'm actually about to do something similar with my Civic. I'm driving to Detroit for a baseball game on July 4th weekend, and I'm also due for a dose of Gumout (All in One). So I'm planning on filling up and adding the Gumout a few days before I leave, and will burn through about a quarter tank or so of normal driving around town, and then about 3/4 of the tank will be all highway.

I did have a problem with this Civic a few years ago where one of the injectors was leaking on shutdown, causing hard starts and 7% fuel showed up on one of my used oil analysis! I solved it with a couple of doses of different Gumout products (Regane fuel system treatment and their cheapest injector cleaner) IIRC, I drove a mix of everyday driving and longer highway runs with those treatments, and they worked very well for me, solving the hard starting and reducing my fuel in used oil analysis to zero! That's why I stick with Gumout products to this day, as I had proven results.