1. Home
  2. Volvo automobiles
  3. high nox- won't pass 1988 240
  4. Page 2

high nox- won't pass 1988 240

Reading the MSDS at first glance my take was that it was kerosene with a touch of butyl acetate as a strong detergent and octane improver.

Exactly. Name brand fuels are all slightly overdoped when the trucks leave the tank farm. The noname fuels are doped to the minimum requirements. If the FL DOT reports are to be believed then by using fleet gas (for the most part, some receipts named general gas station brands in a few instances) supplied by the lowest bidder, then any concentrated detergent package would clean up the fuel system and make it run better. Furthermore, domestic engines are a lot "looser" in order to accomodate the typical lax maintainence they experience.

A well maintained motor will pass almost any emissons test currently in use it's only the ill maintained beasts that benefit from a cleaning anyway. As far as Volvo's go I've had enough engines apart to know that most suffer no appreciable valve head deposits, minimal carbon build up on the pistons and as long as the owners use the recommended grade of gasoline no appreciable injector restriction. Consequently all the cleaning in the world will have very little to no effect on NOx production. There are many compounds that do indeed modify the the smoke and soot creation in diesel fuels that as a side effect reduce NOx creation by providing extra oxygen during combustion and simultaneously lowering the flame temperature. But from what I've researched no such chemistry exists for the shorter hotter burn time of gasoline combustion. The reality is that any attempt to reduce a pollutant measures at a fraction factored by 10**3 ppm would require an addition of some unknown noncataltyic reactant in approximately the same range in order to effect a reduction in the emissions produced by combustion.

4000 ppm over an unknown time slice is what I see in test results from 240s that have had the converter punched out. So if a converter's reduction section drops the results to under 1700 ppm during the same test then a 57% reduction is a big deal. To get the same result chemically by doping the gas so that the NOx emission would be reduced continuously then I expect the added cost to gasoline would be far in excess of what a converter would cost over say 100K mile lifetime.

Bob

Reply to
User
Loading thread data ...

So it'd be cheaper to just buy injector cleaner?

Reply to
Frederico Alfonso de Nurk

RxP does clean the injectors and cleans out the carbon. The RxP concentrate absorbes a lot of heat into the fuel mixture itself so less heat makes it to the metal meaning the engine does run cooler and it does reduce Nox emissions.

For $6.99 + tax, you can buy some RxP at Autozone in your town and just try it out. It doesn't matter if you have the head of the Florida DOT come to your house and tell you the test is valid because the skeptics (in reality cynics) will just find something to complain about.

The ONLY way you will know if it works is by using it. Anyone here that

thinks they can debunk it with rhetoric should just buy a few little bottles and try it out on a few tanks in a row and give it an honest test. $6.99 won't break you but you just might find out that it really does work. Anyone that wants to take the time to try and pick apart documentation should be open minded enough to go try it themselves, based on the opinions here of what it is, it is obvious it definitely won't damage anything. Lets see just how open-minded the thoughtful ones are by trying it themselves and posting the results here.

Frederico Alf>

Reply to
qiman13

You insult our collective intelligence.

Fair enough. It doesn't seem dangerous to the engine or fuel system, like the acetone hoax can be. If people want to spend $7 on RxP I don't see the harm.

Mike

Reply to
Michael Pardee

Well, be sure to run a couple tanks through after you've tried it if you're taking it in for a smog test. The (CA) sniffers react badly to fuel additives. Good way to fail a test for sure.

Reply to
Clay

Being a grump, I am certain the NOx will not be improved. The on-line literature describes the NOx benefits as coming from decarbonizing, although I have never known decarbonizing to be a fix for failing NOx emissions in any car... and I've been DIYing since before any NOx controls or testing were implemented in the US.

Indeed, the unorthodox theory of "radiation containment" would ensure a

*higher* NOx if it actually worked as described; the higher combustion temperatures would mandate more NOx formation. I canna change the laws of physics....

Mike

Reply to
Michael Pardee

I'm just saying, be sure it's all flushed out of the system by running a couple tanks of 'untreated' gas through it before smog testing the car.

When I had my '83 in for it's first test, it pinged at cruse and failed because of high NOx. The tech (who is a pretty sharp guy... I've been back to him several times in the last 10 years) suggested several fixes including a new cat and 'decarbonizing' by pulling a vacuum line and sucking some water through the motor. I've done this successfully on Detroit iron. Actually, we would run a hose from the windshield washer (full of /plain/ water) into the breather. Run it down the highway and give it a couple squirts. Worked like a charm. I don't think I'd try it on the Volvo though...

Reply to
Clay

The idea behind decarbonizing is that it reduces the effective compression ratio, which will lower combustion temperatures, which will reduce NOx formation. In practice, my uncle once used GM Top End Cleaner in his '84 240 (among a couple of other things) to pass PA emissions. (This was before he (and I) knew about disconnection of the vacuum line going to the ignition computer to reduce NOx.)

This is not to say (in fact quite the opposite) that I believe that the product under discussion will have any effect on emissions, positive or negative.

Reply to
Mike F

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.