Need help
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7th Gear
Joined: Nov 2022
Posts: 7
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Need help
I have a 17 stingray A8. Car runs perfect at idle and cruising speeds and through 1st gear, every gear after that at wot the car breaks down and hesitates right before and after shifts. It throws a blinking cel light that goes away. Comes back a cylinder 7 misfire. Changed all plugs and most plug wires and I even changed out the coil pack for cylinder 7. Still has blinking cel light, And breaks down still at wot. Any ideas? Car ran perfect with a couple mods and a tune before. until I recently decided to switch it over to e85 and I happened to put really trash e85 in the car and it went down hill from there. Tried switching it back to 93 and it still pops the blinking cel light.
Burning Brakes
Joined: Sep 2022
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From: MSP
have you run through the tank of 93 yet or are you on some mix of garbage e85?
could also be high water content in that e85 that clogged your fuel filter, too. worth checking. either replace the filter or, instead of throwing parts at an undiagnosed problem, check the fuel pump flow rate. should be a spec out there somewhere for how much it should push over a certain amount of time.
could also be high water content in that e85 that clogged your fuel filter, too. worth checking. either replace the filter or, instead of throwing parts at an undiagnosed problem, check the fuel pump flow rate. should be a spec out there somewhere for how much it should push over a certain amount of time.
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Have you thought about taking the car to a local auto parts store and having them run a scan to see what codes may be set? Many of the stores will run the scan for no charge.
Burning Brakes
Joined: Sep 2022
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From: MSP
that said, your fuel filter is designed to separate water out of fuel. if your garbage e85 had a ton of water in it, that'd do it.
but we're getting ahead of ourselves here. what was trash about the e85 you put into it?
Team Owner
Joined: Jul 2004
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From: Hartford WI
Wires look similar length so I would have swapped coil and wire with another cylinder and cleared the code to see if it comes back. IF it does, the problem isn't in the coil or wire. It should only migrate to the other cylinder if it is swapped and faulty. How is the plug? If that isn't it, I would check compression because the next thing I look at is the injector. Crap could be in the basket filter if there is one or in the injector pintle.
Thread Starter
7th Gear
Joined: Nov 2022
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that's... not what isoheet does, at all. isoheet is mostly isopropyl alcohol -- somewhere between 75% and 99.8%, in fact. it's not doing anything really helpful in temperatures above -30°F. the ethanol content in your fuel is pulling the water into solution above those temperatures.
that said, your fuel filter is designed to separate water out of fuel. if your garbage e85 had a ton of water in it, that'd do it.
but we're getting ahead of ourselves here. what was trash about the e85 you put into it?
that said, your fuel filter is designed to separate water out of fuel. if your garbage e85 had a ton of water in it, that'd do it.
but we're getting ahead of ourselves here. what was trash about the e85 you put into it?
Thread Starter
7th Gear
Joined: Nov 2022
Posts: 7
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Wires look similar length so I would have swapped coil and wire with another cylinder and cleared the code to see if it comes back. IF it does, the problem isn't in the coil or wire. It should only migrate to the other cylinder if it is swapped and faulty. How is the plug? If that isn't it, I would check compression because the next thing I look at is the injector. Crap could be in the basket filter if there is one or in the injector pintle.
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Team Owner
Joined: Jul 2004
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From: Hartford WI
Team Owner
Joined: Jul 2004
Posts: 28,502
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From: Hartford WI
Burning Brakes
Joined: Sep 2022
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From: MSP
But isoheet is also used to evaporate some water from the tank correct. The content was reading around e20. The only reason I knew that is because I took it to my tuner and had him look over everything cause I though something was off with the tune. But everything seem to be good tune wise.
if you were getting e20 from an e85 labeled pump and are in the US, that's.. a problem. last I checked, e85 must be between e50 and e83 according to... I believe federal law?
unless you filled up at Billy-Bob's Budget Gas and McDonald's, I would question your flex sensor before questioning the fuel. if the flex sensor is reading incorrect ethanol content and applying a trim that's different to what the actual fuel is, that'll cause some fun problems. with your 93AKI you should be seeing about E10 on your sensor. maybe give that a check to rule it out?
Team Owner
Joined: Jul 2004
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From: Hartford WI
no, isoheet is pulling the water into solution. no evaporation is happening.
if you were getting e20 from an e85 labeled pump and are in the US, that's.. a problem. last I checked, e85 must be between e50 and e83 according to... I believe federal law?
unless you filled up at Billy-Bob's Budget Gas and McDonald's, I would question your flex sensor before questioning the fuel. if the flex sensor is reading incorrect ethanol content and applying a trim that's different to what the actual fuel is, that'll cause some fun problems. with your 93AKI you should be seeing about E10 on your sensor. maybe give that a check to rule it out?
if you were getting e20 from an e85 labeled pump and are in the US, that's.. a problem. last I checked, e85 must be between e50 and e83 according to... I believe federal law?
unless you filled up at Billy-Bob's Budget Gas and McDonald's, I would question your flex sensor before questioning the fuel. if the flex sensor is reading incorrect ethanol content and applying a trim that's different to what the actual fuel is, that'll cause some fun problems. with your 93AKI you should be seeing about E10 on your sensor. maybe give that a check to rule it out?
Let's say you are right. Why 7 and not the rest of the injectors?
Burning Brakes
Joined: Sep 2022
Posts: 1,202
Likes: 569
From: MSP
Yeah, a wonky ethanol content reading would probably show up as random misfires, you're right.
My original idea is that cylinder 7 could be end-of-line on the fuel system, but after looking up what I could find, it looks like both cylinders 7 and 2 are the furthest away from the fuel pump. Still not unreasonable to see 7 (or 2) misfiring first in a starvation scenario, which goes back to the waterlogged fuel filter theory, but a bad flex sensor trimming should be hurting all cylinders.
Thread Starter
7th Gear
Joined: Nov 2022
Posts: 7
Likes: 0
no, isoheet is pulling the water into solution. no evaporation is happening.
if you were getting e20 from an e85 labeled pump and are in the US, that's.. a problem. last I checked, e85 must be between e50 and e83 according to... I believe federal law?
unless you filled up at Billy-Bob's Budget Gas and McDonald's, I would question your flex sensor before questioning the fuel. if the flex sensor is reading incorrect ethanol content and applying a trim that's different to what the actual fuel is, that'll cause some fun problems. with your 93AKI you should be seeing about E10 on your sensor. maybe give that a check to rule it out?
if you were getting e20 from an e85 labeled pump and are in the US, that's.. a problem. last I checked, e85 must be between e50 and e83 according to... I believe federal law?
unless you filled up at Billy-Bob's Budget Gas and McDonald's, I would question your flex sensor before questioning the fuel. if the flex sensor is reading incorrect ethanol content and applying a trim that's different to what the actual fuel is, that'll cause some fun problems. with your 93AKI you should be seeing about E10 on your sensor. maybe give that a check to rule it out?
Le Mans Master
Joined: Feb 2010
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From: Santa Fe Tx
I have a 17 stingray A8. Car runs perfect at idle and cruising speeds and through 1st gear, every gear after that at wot the car breaks down and hesitates right before and after shifts. It throws a blinking cel light that goes away. Comes back a cylinder 7 misfire. Changed all plugs and most plug wires and I even changed out the coil pack for cylinder 7. Still has blinking cel light, And breaks down still at wot. Any ideas? Car ran perfect with a couple mods and a tune before. until I recently decided to switch it over to e85 and I happened to put really trash e85 in the car and it went down hill from there. Tried switching it back to 93 and it still pops the blinking cel light.
Get code reader and read codes- check online as to what they mean?
Quit putting e85 gas in the car. I am not a fan of running anything but 93 oct in any of my cars. In some cars you'll get better mileage with 93 which will off set some added cost? but it will burn cleaner too.
Sounds like disolved water in the e85 fuel. If so it will take time to get it out.
Corvettes are wierd animals concerning plugs, wires and coils. I changed all my Plugs in my 2007 Z06 to hotter plug and it threw codes- changed back to oem plugs no problem. If your changing plug wires I do all at same time. My point is that corvette can be temprimental ????
Team Owner
Joined: Jul 2004
Posts: 28,502
Likes: 3,302
From: Hartford WI
Quit putting e85 gas in the car. I am not a fan of running anything but 93 oct in any of my cars. In some cars you'll get better mileage with 93 which will off set some added cost? but it will burn cleaner too.
Sounds like disolved water in the e85 fuel. If so it will take time to get it out.
Corvettes are wierd animals concerning plugs, wires and coils. I changed all my Plugs in my 2007 Z06 to hotter plug and it threw codes- changed back to oem plugs no problem. If your changing plug wires I do all at same time. My point is that corvette can be temprimental ????
Sounds like disolved water in the e85 fuel. If so it will take time to get it out.
Corvettes are wierd animals concerning plugs, wires and coils. I changed all my Plugs in my 2007 Z06 to hotter plug and it threw codes- changed back to oem plugs no problem. If your changing plug wires I do all at same time. My point is that corvette can be temprimental ????
He has run 2 tanks of 93 in it already. Besides, why 7 and not the others if it is a fuel problem?
If you change the specs *****-nilly, any car can be a problem. Corvettes are not special in this.
Burning Brakes
Joined: Sep 2022
Posts: 1,202
Likes: 569
From: MSP
it's why they are regularly tested, stickered for compliance, and fined/shut down if they are noncomplaint.
it's why you go to top tier certified gas stations, because if they ever serve fuel that is not inclusive of the advertised detergent package and the advertised AKIs, they get heavily fined or shut down.