10,000 mile FI driver report

[Paul Y.]

Re: 10,000 mile FI driver report

There are "issues" with the E10 distillation curve that are the likely cause of percolation problems that many are experiencing (though some appear not to), and I am currently gathering data on this issue.

Beyond this the accusations that E10 is causing various fuel system degradation problems like corrosion and deterioration of gaskets and elastomeric materials is not supported by evidence.

E10 has been around for nearly 40 years and industry upgraded fuel system materials at about this time to tolerate E10, but no organic material lasts forever, and the higher temperatures they are exposed to the more quickly they deteriorate. For example, the rubber hose between the frame fuel pipe and fuel pump inlet nipple runs much hotter than the hose that connects the fuel tank nipple to the frame pipe, so the former won't last nearly as long. I'd advise changing all engine compartement rubber fuel hoses every 100K miles or 15 years, WHICHEVER COMES FIRST!!!

Most automotive elastomers are in the "nitrile" family and they degrade rapidly above about 200F. Viton is by far a better material since it can withstand in excess of 300F before is begins to rapidly deteriorate, so it is the best material choice for O-rings and any engine internal elastomeric component like valve seals.

Here's one of those live and learn stories. From 1971 to 1975 when the Air Force had me in Grand Forks, ND I stored the SWC in my parents garage in Seattle. Part of my storage procedure was to completely drain the fuel system. When I was ready to move the SWC to California in March 1975, the first thing I did was add about 3 gallons of fuel, but shortly thereafter I noticed a leak. The hose from the frame fuel pipe to the fuel pump inlet nipple had a split and was leaking fuel. It was the orignal hose installed at St. Louis and was now 12 years old and had about 112K miles.

I removed the hose and plugged the fuel pipe with my finger while my dad drove down to a local gas station owned by a high school classmate. I had to play my "little Dutch boy" routine for about 15 minutes until my dad got back with the new length of fuel hose, and once it was installed I quickly got the engine started and everything else was okay, but it was a good lesson.

It's also important to realize that because of the high tank location in C2/3 Corvettes if this hose fails - or if any other leak occurs between the tank and fuel pump inlet - the entire contents of the fuel tank will drain out, and I have since heard a number of stories about this.

Modern fuel hose materials are much better and last longer, but still not forever.

Duke

Duke, I believe that my spider has percolation on hot restarts but I can always get it going by feathering the throttle and playing with it a bit. It always starts fast like first turn over.

[Paul Y.]

Re: 10,000 mile FI driver report

Paul,

The rubber used to make the o-rings that you have is different from the rubber in the o-rings used in 1963. While the spec may be the same, compounding varies due to many reasons such as cost, EPA rules, ingredient availabitlity, etc. Specs changed in 1990's (or before) after many people complained about electric fuel pumps getting eaten up. The recipes changed. In addition, Chinese reproductions and replacement parts use these recipes, as it's highly unlikely that they don't have access to the newest formulations. It only makes sense that newer rubber components will resist ethanol better because they are newer (not old) and because the formulation is different.

While I'm here I'll also mention that some people on this forum have used the ethanol degradation of small engine fuel lines as examples. These lines are made from PVC and other vinyl compounds that are not the same as the rubber components that we are talking about.

Paul, I believe that part of your experience is due to the fact that when you get home you fill the tank with non-ethanol fuel, so the rubber components in your fuel system are only exposed for short periods of time before the ethanol is either greatly diluted or gone. Some of the rest of your good fortune is due to the compounding differences in modern rubbers.

Paul

P.S. Thanks for posting this. It's good information.

Paul, I am using parts from rebuild kits that I bought from GM in the 80's an I believe they feel a little better than the repo kits when I am installing them. I also(now don't gag on me) put 1 ounce of marine two stroke oil to 5 gallons of gas when I gas up. The inside of my injector is spotlessly clean and the adapter plate is clean and the intake valves that I can see are clean also so I am convinced that the two stroke oil is benificial. It is also a cheap add as you can get 16 ounces from Wal Mart for $ 2.47 and treat 80 gallons. It makes the gas smell good too. I also can tell a real difference when I fill it with ethanol free gas.

[John D.]

Re: 10,000 mile FI driver report

Paul, Nice to see you are not having fuel injection woes because of ethanol. But let me tell you that your case is not the norm. IF it was my phone would not ring EVERY day with the same complaint. Fuel Injection leaking gas onto the hot manifold.
As a member of the Pittsburgh chapter I am often asked to do a seminar. One that I am asked to do the most (two times) is titled, "The Evils of Ethanol"
As part of this presentation I have an array of beakers lined up that are labeled as following.
Buna rubber parts and Viton rubber parts.
You should see how the buna rubber parts swell up with ethanol agitating them so to speak. Just like a Krispy Cream donut I say.
The viton rubber parts dipped in ethanol show no ill effects.
Now for the phone call info. Daily I receive a call from somewhere in the USA about a leaking fuel injection. The most common complaint is the o'rings are leaking.
Although labor intensive its very cheap to replace the original buna rubber o'rings with viton ones. That will solve a lot of the problems.
The hardest problem to fix is if the hi-pressure pump (where the drive cable goes). These is a viton pump seal to replace the buna rubber seal.

If you are a non believer play around yourself and test some rubber parts in ethanol.
Watch out for the rubber hose that goes from your engine fuel pump to the steel gas line. Man do they swell up in ethanol.
But if you don't believe me and think it's hype to make money it's fine with old JD here. I wish I would not get so many of the complaints on leaks as can't get any work done. But for my the rest of my life I am here to serve the hobby until I am six feet under. And I do it in a courteous way no matter how uneducated the guy on the other end of the phone is. John

[Bruce B.]

Re: 10,000 mile FI driver report

John,
Thanks for the great information.
I think seeing your beaker display at Carlisle would be very interesting.
Hope you are doing well.
Bruce B (RP 4360)

[Paul Y.]

Re: 10,000 mile FI driver report

Paul, Nice to see you are not having fuel injection woes because of ethanol. But let me tell you that your case is not the norm. IF it was my phone would not ring EVERY day with the same complaint. Fuel Injection leaking gas onto the hot manifold.
As a member of the Pittsburgh chapter I am often asked to do a seminar. One that I am asked to do the most (two times) is titled, "The Evils of Ethanol"
As part of this presentation I have an array of beakers lined up that are labeled as following.
Buna rubber parts and Viton rubber parts.
You should see how the buna rubber parts swell up with ethanol agitating them so to speak. Just like a Krispy Cream donut I say.
The viton rubber parts dipped in ethanol show no ill effects.
Now for the phone call info. Daily I receive a call from somewhere in the USA about a leaking fuel injection. The most common complaint is the o'rings are leaking.
Although labor intensive its very cheap to replace the original buna rubber o'rings with viton ones. That will solve a lot of the problems.
The hardest problem to fix is if the hi-pressure pump (where the drive cable goes). These is a viton pump seal to replace the buna rubber seal.

If you are a non believer play around yourself and test some rubber parts in ethanol.
Watch out for the rubber hose that goes from your engine fuel pump to the steel gas line. Man do they swell up in ethanol.
But if you don't believe me and think it's hype to make money it's fine with old JD here. I wish I would not get so many of the complaints on leaks as can't get any work done. But for my the rest of my life I am here to serve the hobby until I am six feet under. And I do it in a courteous way no matter how uneducated the guy on the other end of the phone is. John

John, my friend, I am not trying to say that ethanol does or does not swell up rubber. I am convinced that it does. I just am sharing what I am experiencing with an old FI unit that I drive more than most people drive theirs. I repaired the sending unit a couple of years ago and I felt that the 0 ring in that needed replacement and that the trouble that I had with it leaking was possibly from the ethanol. How long does it take for ethanol to swell up the parts in your beakers? Do you think that the marine two stroke oil that I am adding does anything>Duke told me that was mostly mineral oil. I have never used av gas or race gas for more than the last 20 some years. I have replaced the fuel pump to steel gas line within the last couple of years as suggested. I somewhat doubt that I take more care in maintenance than the average fuel injection owner. Like Paul suggested, maybe it is because I keep enough non ethanol fuel in the car when I am in town. I don't know why, but I have always been lucky. I am going to contact some of the people that I know that I restored their injections, and see how they are doing. In the mean time, I'm driving it. Thanks for your good comments. Paul

[Don H.]

Re: 10,000 mile FI driver report

John, As I have said before and will say again, THANK YOU for sharing your knowledge of Fuel Injection units. I have found the vitron o-rings localy and see no reason to not use them as a precaution (I use mostly AV gas). Don H.

[Joe R.]

Re: 10,000 mile FI driver report

George,

It is recommended here to not start the car unless you plan to drive it far enough to get the oil up to full temp. Otherwise you're doing more harm than good.

Joe

[John D.]

Re: 10,000 mile FI driver report

Hi Bruce, Hopefully we will be at Corvette Carlisle is same spaces. Also hope the weather changes before the show. John

[Dan H.]

Re: 10,000 mile FI driver report

John, still running the high pressure pump you rebuilt/installed in 1992, using ethanol laced 91 octane gas, I've put 18 thousand miles on it and not a weep ole buddy! Rebuilt a 57 unit recently, it had 1975 date codes on the main diaphram, HP pump was leaking on that one!
Dan

[Joe R.]

Re: 10,000 mile FI driver report

Michael, I forgot to tell you that I took the tin foil beanie and made an insulation pad out of it that fits right under the spider. I made it out of a product called second skin that I insulated the floor with prior to carpet. This last time I put a piece of foil insulation tape around the spider pipe that lies closest to the adapter plate. I am running a 65 spider with the extra pipe plugged and that is the one closest to the adapter plate.

Paul,

I'm sure that Mickey will be glad to know that Aliens will never look under your hood again!!!

You fixed that problem!!!!

JR

[George J.]

Re: 10,000 mile FI driver report

Paul,
I didn't mean the unit smells of gas, just that a rich idle smells.

George

[George J.]

Re: 10,000 mile FI driver report

George,

It is recommended here to not start the car unless you plan to drive it far enough to get the oil up to full temp. Otherwise you're doing more harm than good.

Joe

Joe,
I start it, let it idle, and drive it back and forth in a large garage, and long enough to get the oil temp up. I agree that not letting the oil get to temp would not be good.

George

[Michael G.]

Re: 10,000 mile FI driver report

Hi Paul, glad to hear you're driving your fuelie so much.

While I can't speak to the issues of ethanol's affect on gaskets, etc, I think the evidence is overwhelming that most fuelies have tended to have percolation problems since they were new, problems that are somehow exacerbated by modern fuel with ethanol in it. I'm not convinced the ethanol itself is the issue,it may be that the hydrocarbon mix in E10 causes problems.

In any case, I've historically had some idle and starting problems with my 63 L84 cars in weather over 82 F, so for the last few weeks I've been fooling around with insulating the fuel lines. I've found that I can lower the fuel bowl temperature at least 10 degrees and make 93 octane E10 tolerable in everyday driving, up to 94 ambient. (haven't seen temps higher than this yet). Thursday, i drove my car 230 miles, without stopping, in 85-88 ambient, with 93 octane E10, with no problems whatsoever. At the conclusion of the trip, the fuel bowl temp was 132.7, much lower than I've seen prior to insulation. This trip would have been a nightmare with E10, prior to insulation.

I think the most important step is to shield the lower fuel line from radiant heat of the right hand exhaust manifold, by wrapping it in reflective insulation. I also think that isolating the fuel filter from its bracket has helped a lot.

While I'm not sure its necessary to lower fuel temp more, I now intend to add some insulation under the spider, just for added protection against radiant heat.

I generally use straight racing fuel, or, a mix of 100 racing fuel and 90 octane ethanol-free gas, but it's nice to know I don't have find those on a trip.

[Paul Y.]

Re: 10,000 mile FI driver report

Hi Paul, glad to hear you're driving your fuelie so much.

While I can't speak to the issues of ethanol's affect on gaskets, etc, I think the evidence is overwhelming that most fuelies have tended to have percolation problems since they were new, problems that are somehow exacerbated by modern fuel with ethanol in it. I'm not convinced the ethanol itself is the issue,it may be that the hydrocarbon mix in E10 causes problems.

In any case, I've historically had some idle and starting problems with my 63 L84 cars in weather over 82 F, so for the last few weeks I've been fooling around with insulating the fuel lines. I've found that I can lower the fuel bowl temperature at least 10 degrees and make 93 octane E10 tolerable in everyday driving, up to 94 ambient. (haven't seen temps higher than this yet). Thursday, i drove my car 230 miles, without stopping, in 85-88 ambient, with 93 octane E10, with no problems whatsoever. At the conclusion of the trip, the fuel bowl temp was 132.7, much lower than I've seen prior to insulation. This trip would have been a nightmare with E10, prior to insulation.

I think the most important step is to shield the lower fuel line from radiant heat of the right hand exhaust manifold, by wrapping it in reflective insulation. I also think that isolating the fuel filter from its bracket has helped a lot.

While I'm not sure its necessary to lower fuel temp more, I now intend to add some insulation under the spider, just for added protection against radiant heat.

I generally use straight racing fuel, or, a mix of 100 racing fuel and 90 octane ethanol-free gas, but it's nice to know I don't have find those on a trip.

Michael, I have always had some type of insulation under the spyder in all of the miles (even back in the 80's) I used to have a piece of asbestos wrapped in foil and now I use some second skin which is designed for insulation under the carpet,doors,firewall, etc. It is butyl and foil and has a high melt resistance. Can you show me what you are using to insulate the fuel line where it comes out of the frame and attaches to the fuel pump by rubber hose? I think that trying that is a no brainer and I would like to do that. Also what are you using to insulate the fuel filter from the bracket. I would adopt that also as I see the value. When I stop to regas on a road trip is when I find that the perculation in the worst. I find that it will start right up but act like it is out of fuel so I have to keep tapping the throttle until it seems the check valve in the spyder opens and I get a steady supply of fuel until it runs smoothly, then it goes well after that. It does start up and idle fairly easy. But if I try to give it some gas to accellerate is when it acts short of fuel. The same symtoms happen on hot restarts but I usually open my hood at cruizes and car shows so it cools a bit faster it would seem.

[Michael G.]

Re: 10,000 mile FI driver report

Paul, I've done four things:

1) I have wrapped the fuel line from under the battery to the fuel pump with the tape shown on the bottom in my pic. This is an adhesive-backed insulating cloth with a foil top layer, available at many auto parts stores. Note that the heat will loosen the adhesive, so I've tied the ends with tie straps. (note that if I had had an empty fuel tank, I would not have wrapped the line, but would have disassembled this pipe and used insulating cloth tubing instead of tape, as I did the pipe in step two below)

2) I disassembled the front fuel line and slipped the tubular insulator (shown in the middle, below) over it, all the way down to the fuel pump. Again, tying the ends with tie-straps. This is a foil-backed insulating cloth tube, with no adhesive.

3) I removed the filter and wrapped the outside with the insulating cloth tubing (shown on top of my pic). I did this once at each end. I then wrapped adhesive-backed insulating taped around it to reflect heat and hold the cloth in place. I had to bend the filter bracket open a bit to accept the bigger diameter of the wrapped filter. The clamping screw is no longer used.

4) I slipped insulating cloth tubing over the line from the filter to fuel bowl and tied the end with straps.

I then re-assembled the whole thing. I don't have the car here today, but will post some pics soon.


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