A big hello to all you folks from Tucson, Arizona! Proud, proud new driver of 1999 Light Pewter (is there a Dark?) FRC. Started off wanting a Z06, but realized FRCs had their own charm. And economy. Two-sentence story: I autocrossed the car last Sunday and was going slower than my Miata until someone said "Turn off Active Handling!" Went faster than the Miata. I chose the right day for an epiphany.

I'm also sure my post has some elements of site navigation (and "search"), but I've gone over all of what my searches on both this site (the best, BTW) and Google (which inevitably takes me back here) on two topics:

EBCM and Fuel Pump - specifically, are there, and if so what are, ways to predict failure of these components. I don't mean actual roadside breakdowns, or lights and alerts because, by that time, the component has in most cases, actually failed. And, any workarounds?

Details

EBCM - The solder problems of the unit and the early-model manufacturing characteristics that make this unit impossible to service are already well-documented. What's a little sketchy to me is how to predict imminent failure and (seriously) how important this unit is to DD and even competition such as autocross. None of my previous DD/autocross cars up to an NB Miata ever had ABS (or TC) and we all did just fine. I never suddenly lost control in the wet or landed in a ditch. Just a matter of driver mod? An inadvertent, unfair advantage for those who have over those who haven't? Hope BStreet guys chime in.

Fuel Pump - More murky, here. I have read everything from "it went away" and apparently never came back, to "I'm going on a long trip and I need to fix this before leaving" panic state with the implication: it will happen. I have experienced this on a drive (filled up before I hit the highway) that went for ~ 1 hour, stopped the car for a snack and bathroom, and came back to hear new whine from right behind driver's seat. I've heard this whine before in the NB, only much more constant and lower intensity - inaudible with RE71R noise past 30 mph. On the other hand, at 70 mph, I could hear the C5's fuel pump whine over the loud, older Hankook R-S3s and undulated in sync with the turn signals (so I'm sure it's electrical and not mechanical, well, you know what I mean). The next day? Whine is gone, engine pulls strongly till it bounces off limiter just like before whine. I'm thinking, just a two-tank, siphon-transfer, heat-soak pressure buildup thing. All good. Maybe. On waaay the other side of this is "I heard the noise, changed the fuel pump fill-in-the-blank times, and it was back every single time before I could even drive home from the shop." So, maybe this is "normal", after all? Are all "peace-of-mind, pre- long drive" discarded fuel pumps eBay good? Just too many "maybes" in this paragraph.

I could: 1.a. pull the fuse on the EBCM and see if I could get used to it, or until the DIC drove me crazy, and 1.b. wait for the fuel pump to die, risking me in the petrified forest without a paddle, figuratively. 2. try to do a real scientific survey (oxymoron?) of how often failures of these units occur, and are/were there any warning signs. Or 3., standby while some exemplary individual figures out how to update - more importantly - replicate, with newer parts. Or, totally eliminate (no nanny lights, even) ABS and TC. My best outcome would be an adjustable, mechanical (more reliable, less expensive IMHO) proportioning valve, but that would be too reasonable for the General. I think I'll wait.

Other than that and with a sense of humor, the car has been a total blast and I would buy it again. Maybe raise it a bit, but that's chicken feed compared to the ECBM mania and fuel pump panic.

Best and TIA,
MR2

 

Is this an example of 'creative writing' ?

 

Once I had the fuel pump whine and drove a lot that day, it kept getting louder, and also turn signal made the whine modulate, reminded me of the background noise sound effect on the 1960s Star Trek, well it got louder and louder, I finally pulled into gas station even though tank was at half and ran out of gas!

I was there probably a hour and a half because the gas station's atm system was down and I had no cash, they wouldn't even let me pump 5 bucks worth with them holding my driver's license, finally I helped a guy push a pickup while his wife steered it into station, they gave me 5 bucks and I wanted to repay them, the guy said don't worry about it, they had another car and we're waiting for the tow truck to come get the broken down pickup.

After pumping 5 dollars worth, went home and no whine.

It has never done that again, I started using techron concentrate, and I think it fixed the gauge issues, what was your gauge showing when you heard the whine?

 

My fuel pump will whine on really hot days sitting in traffic, then disappear the next morning when it's cool. Mines a 2004 so supposedly it has a "quieter pump" compared to the earlier cars. Of course, 2004 has a different tank system then earlier years as well so maybe that's related? I've run Techron concentrate to some success, but I expect to hear it again as the weather warms up again. You sit very close to the fuel tanks in these cars, I'd say even closer then an NB, spent this last weekend in the trunk of an NB swapping the rear suspension so I'm familiar.

If you're not noticing any performance loss, I wouldn't worry too much about a bit of whine.

 

I had filled the tank just before leaving (Chevron 91 w/ Techron, of course). Drove for about an hour and took a break. If "F" is at 3 o'clock and "E" is 8:30, the gauge was at ~2:00 - 2:30 by the time I climbed back in the car and first heard the whine upon starting the engine.

Yes, it was in the low 70s when I drove off and had gotten close to 82* by the time I heard the whine. Speaking qualitatively, no performance loss, so far.

Bottom line, I'll guess that environmental and operational heat is probably the common element in our anecdotes. I don't have any long drives in mind, but the next time I hear the whine, I'll check the temps, pop the gas cap, replace it and see if that changes anything. Running out of gas, though, may be .more than I really want to simulate, right now.

Thank you both for your insights.

 

There is a good write up on the forum about converting a newer ECBM into the older models. Although, I do not believe it pertains to the rear mounted ECBMs. If mine ever fails, I will probably do the swap to the newer part.

 

I replaced my fuel pump (driver's side) and jet pump (passenger side) at 200k miles. My old pump(s) were working fine but my sending units were shot. It was a "while I was in there" replacement.

My old pump would get louder the longer I drove it. After 5 or 6 hours of continuous driving it was very loud but no performance issues. The new pump is considerably quieter however still makes some noise. Noise does not mean imminent failure is lurking.

 

First you need to learn how to read your DTC codes for any problems. You can use your Drivers Information Center (DIC) to pull your codes--numerous articles on how to do it or use your owners Manual. You will also learn the AH/TC lights will also indicate any problems associated with the EBCM. But the problems which occur not always associated with the EBCM but also the wheel bearings, TC harness, Steering wheel position sensor (SWPS) and other gremlins. While my mileage is in the low 40K's I have over 25K of autocross and HPDE miles on my 2000 FRC. I have has SWPS problems--probably wore it out--harness problems and a wheel bearing problems but never an EBCM. When the SWPS wore out it had the same effect as eliminating the EBCM but I still was able to run an autocross event waiting for parts. The car handled like my old 64 Corvette, I could lock up the brakes rather easily and I had to remember how to trail brake again. There is a wealth of information on this site when you have a problem with your Corvette but it really helps to get correct information by listing any DTC codes with the problem. One other item than you should be aware of is the battery voltage. When the car is turned off, use a VOM and measure the voltage of the battery, overnight reading is the best and make sure you have a reading of more than 12.5V. Below that and funny problems may occur with your electrical system. HTH

 

I read that. It's significant that a skilled person could conceptualize, gather and assemble all the components to make this happen. In my original post, I used the word "replicate", which hopefully brings the reality to ordinary folk, like me, a little bit closer

Thanks for this info. There's a couple of levels I'm starting to process data as it comes in: Level 1 - I don't really understand why, but I do have data to suggest that fuel pumps get noisy when they run long and hot, but not followed by imminent failure, and that's enough for my purposes; and Level 2 - I can understand why combining certain fuel in an early C5 with the tendency of the sensors to malfunction points to a certain brand. In my earlier life, I ran a factory that used bunker fuel for our furnaces and because Shell used a lot of "sweet" crude from Indonesia, their fuel always had more sulfur than other brands. More service-related problems. That said, a good compilation of Level 1 allows me to focus on the really important problems rather than throw time (and money) on less important issues. One question: did you try Techron treatment to get you to 200K mi before the sensors needed replacement?

I appreciate the autocross/HPDE specific data! I can see how SWPS and harness would have issues on the constant steering inputs that come with fast driving, but also puts a perspective on just where the EBCM stands in the universe of issues that comes with competition. A local autocrosser told me about the hubs. I too, acknowledge the side-loading of the various, but most intensely on the front, wheel bearings as 3,000+ lbs of car constantly changes direction on sticky tires. The best part is that the car is still learn-able without the nannies, even if it compares to a 64 Sting Ray. Trail braking and trailing throttle are good fallbacks. Does having the car hooked to a battery tender help with the 12.5V threshold?