Fuel quality problem masquerading as EGR valve fault ?

[bluesunbeam]

In mid-May my 2001 MT with 63k miles on it began to display signs of the bucking/herky-jerky/hunting problem much discussed in this forum . The symptoms only manifested themselves between 1500-1900 rpm under gentle acceleration in 4th and 5th gear and the car would then bring in some assist until higher up the rev range and then settle down and happily run as normal. I ordered an egr plate gasket and was told it would be 8 weeks before it arrived . Whilst waitng for the gasket i had noticed the problem varied considerably at times and i started to get a vague idea that it was connected to where i filled up with petrol and seemed worse when i used the garage just around the corner from me . This is not the first time i have noticed changes in performance in vehicles when using this garage but the other times it has been with motorbikes with plenty of power and i put it down to atmospheric conditions or the machine needing a service etc. I stopped using this garage to get fuel and the Insight gradually improved and is now back to normal after four months .
I found a post by Weslich with a similar story but no others and wondered if anyone else can cast any light on this situation . I assume that the Insights lean-burn mode will highlight any fuel quality problems or is this poor logic ?
A mate of mine is going to get hold of some pellets that are used in aviation to check for contaminated fuel and i will check the fuel from this garage. I realise the true test would be to go back to using fuel from this garage but i cant bring myself to do it .

[interestedguy]

its funny you say that.

I have a 2001 with 65K on the clock, within the last 200 miles the EGR, the spark plugs, the air filter, and the grounding straps were replaced. I also cleaned the EGR plate, my EGR plate gasket came from majestic honda fast.

With all that done I still had the same issue you are describing, at very light throttle in high gears it was still not smooth.

I ran the tank to empty and filled up with premium Chevron gas and put in PRI-G fuel stabilizer, it claims to be able to turn gunk back into usable gas. Just that easily the problem was fixed.

I spent allot of time and money that didn't fix it. I am thinking you are right it was poor gas.

[kennysmith]

I got a killer deal on my car w/80k because the PO could not solve the herky problem which I found described everywhere on this site. I now have over 100K, and solved the majority of the problem months ago with EGR valve repair, but just near where I will drop out of lean burn I still have what you describe. I thought the solution was cleaning the EGR plate which I still have not accomplished, but i'll try Interetedguys approach and report back.

[AbCaRed00]

Good chance old gas that's been stored a long time prior to reaching the pumps could be the problem you're experiencing, if not long term buildup within the stations tanks themselves being the main cause. Fuel long in storage can degrade via oxidation to form gummy resinous deposits that will mess up an engine with repeated use. Also, the point often made about not to be fueling up too soon after the gasoline tanker truck has just delivered it's load is quite valid: all those heavier resins and muck etc in the bottom of the tanks is stirred up turbulently on delivery. Filters or not, it can get into your fuel tank from the stations tank until the heavier stuff settles back down to the bottom.
Having seen for myself the inside of the huge fuel storage tanks at a major refinery while involved in 'confined space' industrial cleaning of same via vacuum trucks using snow shovels, be assured these tanks can and do have quite a buildup of residues. It may be the luck of the draw what station gets a bad batch, but I'd suspect discount gas stations obtaining fuel from a major supplier might have cheaper fuel for a reason.

That fuel stabilizer or others similar will definitely help dissolve the bad long term stored fuel, as "like dissolves like". Paraffins and naphthalene are the major constituents of the greater part of that fuel stabilizer mentioned above. It contains ShellSol D60 solvent which is half and half of the C10-C12 compounds above. The remainder of the stuff in the PRI-G and similar products contains anti-oxidant amines that prevent formation of the resins inside the tank if gas is left in for a while over a winter for example. The remainder of the mix is likely a metal deactivator that binds up metal salts in the fuel. These can accelerate formation of the gummy resinous deposits. The three constituents work to dissolve, prevent, and discourage buildup of resinous gummy fuel.

I've been running only Top Tier spec fuels [specified by BMW, Honda, Toyota, GM, MB, VW] containing a high detergent content formulation in my Insight. I now use regular low anti-knock index gas, lately now a brand with more open chain alkanes for cleaner burning than higher energy aromatic content. The previous owners formerly used discount fuels then switched to more high detergent name brand premium fuels after having to replace a catalytic converter in '08.
I'll always try to fuel at places with a high volume of sales wherever possible, stick to top tier spec fuels, and avoid fueling when the tanker truck is there as much as possible.
With the long range of the Insight I find locating a place with good fuel is easy to plan most of the time and I've been fortunate thus far. If I was going to store my Insight for any length of time, I'd add a dose of that fuel stabilizer or something similar in advance.

[kennysmith]

Geez interestedguy, why didn't you purchase something I can find around here? Actually, we don't live that far from each other, where did you find it? The only place I see is possibly West Marine in Jantzen Beach.

AbCaRed00, sounds like you know these products, do you have a recomendation? I've always used cheap gas and no additives in my cars most of which I've driven between 200K and 300K w/o cleaning injectors, but I would like to give something a try.

[AbCaRed00]

AbCaRed00, sounds like you know these products, do you have a recommendation? I've always used cheap gas and no additives in my cars most of which I've driven between 200K and 300K w/o cleaning injectors, but I would like to give something a try.[/QUOTE]

I don't know a lot of the the marketed products particularly, just the general constituents and a few brands used in the workplace. We used Lucas provided by the employer regularly when fueling especially in wintertime up north, but really don't have any one favorite brand. There are lots on the market but Sta-Bil is really widespread, likely in your area as well. No preference though.
Not much is needed for storage purposes to park a car for a while, so if needing just enough for one full tank on an Insight, Harley Davidson sells a high quality fuel stabilizer that's under ten bucks, and treats exactly ten US gallons, so it's about right size dose for the Insight and cheap insurance. It's only four ounces container and will keep a tankful of gas good for up to a year.
If you're putting on the miles the fuel will be flowing and things won't get gummed up so it may be unnecessary. It's when vehicles sit, especially with the ethanol blended fuels that problems can develop. When using a fuel stabilizer for storing a vehicle or small engine, run it awhile after adding the fuel stabilizer to get the mix through the lines and injectors.

[interestedguy]

Kenny, we will have to meet up I will just treat your tank out of my bottle that way if you don't see the improvement you don't need to buy one.

I got my PRI-G off the net, I buy very few things at stores anymore.

I picked PRI-G over the other stablizer options because I did alot of research on what the best one would be since I am storing fuel in case we have a earthquake. PRI sells to major firms around the world and is used by the military. My friend left unstablized gas in his mower over the winter and it wouldn't run, after treating it with PRI and waiting a couple hours it started up and ran fine.