[Hollard]

Originally Posted by Joshinator99

Did you guys make any headway solving this P0231 issue? I just added the JMS, set for 17.47V at 70+% throttle, and had this code pop up under a WOT run. I’m not running any E, just the little bit in regular 93 octane here in MA (E08 according to my datalog).

I was confident that the issue with the codes popping up was that I was filling up with too high of E content. Once I had stuck with going as high as E45, I was fine for a while. Since mid-August all the way up to like August 28th.

In between that time, I the car wasn't running great. Just highway cruising or driving around the city, it was fine. But if I was hit the pedal so do a quick short pull or if I was to try to pass someone on the highway, the car would have like a stutter/surge to it. After that, I has do a couple of full fill-up cycles of just having pump 93 in the car. Used Techron. After running low on the tank and re-filling it up with just 93 again. Would do a short pull and same thing. Did the same thing again, but used up to e40 on the fill-up. Short pull same thing again. So made plans to check and change spark plugs, if needed, for the upcoming weekend. I had purchased OEM plugs for just in case the plugs were faulty and I'll have some on-hand.

Right before that weekend, the code can up again. I had just filled up and was at an ethanol reading of 45%. Did a long pull in a seclude area up to 100 mph and both codes re-appeared. This time there was no stuttering/surging like before when doing short pulls. At this point I'm wondering if the sparks are bad or my coil packs if the codes came back. Maybe that's the true issue.

Well, I continued to drive and car was fine making it into work. Later, I left for lunch. Made it a couple miles down the road to a stoplight. Light go green and I make my left turn. Once I go into 2nd gear, I hear clunking sounds. Seconds later, I see something flying out from the hood's vent. Few more seconds, I notice water drops on the windshield. I quickly pulling into a parking lot, pop the hood, and BAM! Coolant squirting everywhere. The smaller outlet part from the water pump, the hose blew off. And the belt was partially shredder due to all the fluid going on it. Now the question is what the hell would cause the hose to blew off. My coolant temps had always been between 174 - 176 and 179 - 181 with the AC on in city traffic.

So at this point the car has been towed to my parent's place and just sitting in the garage. I might take more of a look at it soon, but no rush since all the racing events I had planned (some pre-paid) to go to has been cancelled with future or TBD dates.

I get it, modding cars comes with headaches, risks, and breakdowns, but at this point I'm just tired. This is the worst issue & incident I've had with the car since modding. If I had did majority of the labor myself on the car, I truly believe I would still have a smile on my face whenever I talk or think about my car. That's how I felt with my 2000 Eclipse back in the days. I did all the labor myself when doing mod stuff. Nowadays, I don't have the time (or patience) to do my own labor work or diagnostic work on the Camaro. The job takes up majority of my time and when I do get a day or two off, I'm trying to plan a nice day for me and the ol' lady.

I might give up on this car. Unfortunately, I been through 4 different shops for performance upgrades & fixes. The last shop I went to I wish I had started with them from the beginning and I truly believe everything would've been done right the 1st time.

I love the Camaro though. I might just get rid of the 2SS and find a used ZL1 or ZL1 LE that had one owner that was a grandma. LOL! Or if Chevy surprise us and place a LT5 in a 2022 or 2023 ZL1 then I'll go for that.

[Joshinator99]

I just lowered my JMS from 17.47 down to 16.50 volts. I’ve rented some dyno time tomorrow and will see if this problem goes away (or not), and will report back.

[gtfoxy]

Originally Posted by Hollard

I was confident that the issue with the codes popping up was that I was filling up with too high of E content. Once I had stuck with going as high as E45, I was fine for a while. Since mid-August all the way up to like August 28th.

In between that time, I the car wasn't running great. Just highway cruising or driving around the city, it was fine. But if I was hit the pedal so do a quick short pull or if I was to try to pass someone on the highway, the car would have like a stutter/surge to it. After that, I has do a couple of full fill-up cycles of just having pump 93 in the car. Used Techron. After running low on the tank and re-filling it up with just 93 again. Would do a short pull and same thing. Did the same thing again, but used up to e40 on the fill-up. Short pull same thing again. So made plans to check and change spark plugs, if needed, for the upcoming weekend. I had purchased OEM plugs for just in case the plugs were faulty and I'll have some on-hand.

Right before that weekend, the code can up again. I had just filled up and was at an ethanol reading of 45%. Did a long pull in a seclude area up to 100 mph and both codes re-appeared. This time there was no stuttering/surging like before when doing short pulls. At this point I'm wondering if the sparks are bad or my coil packs if the codes came back. Maybe that's the true issue.

Well, I continued to drive and car was fine making it into work. Later, I left for lunch. Made it a couple miles down the road to a stoplight. Light go green and I make my left turn. Once I go into 2nd gear, I hear clunking sounds. Seconds later, I see something flying out from the hood's vent. Few more seconds, I notice water drops on the windshield. I quickly pulling into a parking lot, pop the hood, and BAM! Coolant squirting everywhere. The smaller outlet part from the water pump, the hose blew off. And the belt was partially shredder due to all the fluid going on it. Now the question is what the hell would cause the hose to blew off. My coolant temps had always been between 174 - 176 and 179 - 181 with the AC on in city traffic.

So at this point the car has been towed to my parent's place and just sitting in the garage. I might take more of a look at it soon, but no rush since all the racing events I had planned (some pre-paid) to go to has been cancelled with future or TBD dates.

I get it, modding cars comes with headaches, risks, and breakdowns, but at this point I'm just tired. This is the worst issue & incident I've had with the car since modding. If I had did majority of the labor myself on the car, I truly believe I would still have a smile on my face whenever I talk or think about my car. That's how I felt with my 2000 Eclipse back in the days. I did all the labor myself when doing mod stuff. Nowadays, I don't have the time (or patience) to do my own labor work or diagnostic work on the Camaro. The job takes up majority of my time and when I do get a day or two off, I'm trying to plan a nice day for me and the ol' lady.

I might give up on this car. Unfortunately, I been through 4 different shops for performance upgrades & fixes. The last shop I went to I wish I had started with them from the beginning and I truly believe everything would've been done right the 1st time.

I love the Camaro though. I might just get rid of the 2SS and find a used ZL1 or ZL1 LE that had one owner that was a grandma. LOL! Or if Chevy surprise us and place a LT5 in a 2022 or 2023 ZL1 then I'll go for that.

That sucks, but I’ve been there.

Do a leak down as I am suspecting a head gasket. Worst case is a split cylinder wall. Or it could have been a fluke, but I doubt it.

Pull the plugs & look at the ceramic for discoloration or a single fouled plug. Had a cylinder spilt years ago & under 7psi it drove & ran fine. Go over that & it would miss & foul a plug instantly. Swapped injectors & leads (to eliminate specific injector driver (batch fire)) to trace it to that specific cylinder. That was after a full top end tear-down & head inspection & valve-leak check.

Coolant in the exhaust fooks with O2’s. What the ECU may have been seeing is a skewed number. Garbage in/Garbage out as the old saying goes.

[L78toLT1]

I agree with gtfoxy's diagnosis, but just maybe you will get lucky and it will be a fluke. Before going thru gtfoxy's troubleshooting procedure, check your oil, if it's a head gasket there will likely be some oil/coolant mixing.

[Hollard]

Thanks guys! I will do those steps. Especially check the oil for possible coolant mixing and then if not, go into GTFoxy's troubleshooting steps. I have off this weekend, so I'll get to it.

[L78toLT1]

Originally Posted by Hollard

Thanks guys! I will do those steps. Especially check the oil for possible coolant mixing and then if not, go into GTFoxy's troubleshooting steps. I have off this weekend, so I'll get to it.

Don't get discouraged, Hollard. You will get things sorted out. If I still lived in Enon, I'd help you out!

[Joshinator99]

Originally Posted by Joshinator99

I just lowered my JMS from 17.47 down to 16.50 volts. I’ve rented some dyno time tomorrow and will see if this problem goes away (or not), and will report back.

So JMS at 16.50V did not trip the code while on the dyno, but also lost 20 or so psi low side fuel pressure at 726 WHP. I turned it up to 17.00V and it kept up. Pullied down one size on my Whipple (3.50 to 3.25, still not even close to max blower speed), and I lost 20 psi of fuel pressure at 780 WHP. No code at 17.00V, at least. But I’m done trying to fuel this motor off a single in-tank pump. I need to do something much better (either surge tank setup or triple in-tank like Fore).

All on 93 octane BTW, only 8% ethanol.

[gtfoxy]

Originally Posted by Joshinator99

So JMS at 16.50V did not trip the code while on the dyno, but also lost 20 or so psi low side fuel pressure at 726 WHP. I turned it up to 17.00V and it kept up. Pullied down one size on my Whipple (3.50 to 3.25, still not even close to max blower speed), and I lost 20 psi of fuel pressure at 780 WHP. No code at 17.00V, at least. But I’m done trying to fuel this motor off a single in-tank pump. I need to do something much better (either surge tank setup or triple in-tank like Fore).

All on 93 octane BTW, only 8% ethanol.

To be honest, when are we going to go old-school & run a straight pick-up in-tank & use a easily obtainable high volume in-line as the low side pump?

I get the attraction of working off in-tank pumps, but they have always proven to have their limitations.

Don’t get me wrong, 7-800 RWHP, or more, is impressive from factory systems, but with what I’m seeing in terms of the on-demand PWM/ voltage, which has been a thing for like 2 decades now, there comes a point where you can just nip this stuff in the bud.

Maybe I’m off here, & please feel free edumacate me, maybe you guys are & I’m missing that, but the transfer function of voltage vs flow rate @ dynamic pressure is an age old equation.

[KingLT1]

Originally Posted by Joshinator99

So JMS at 16.50V did not trip the code while on the dyno, but also lost 20 or so psi low side fuel pressure at 726 WHP. I turned it up to 17.00V and it kept up. Pullied down one size on my Whipple (3.50 to 3.25, still not even close to max blower speed), and I lost 20 psi of fuel pressure at 780 WHP. No code at 17.00V, at least. But I’m done trying to fuel this motor off a single in-tank pump. I need to do something much better (either surge tank setup or triple in-tank like Fore).

All on 93 octane BTW, only 8% ethanol.

Seems a bit low but your log that you sent me indicated some odd fuel system fluctuations so I wonder if the low side pump you used has issues?

I would expect to see the LT4 in-tank with JMS go that far if not further on 93. My brother's H/C 2300 C7Z is still running the OE in-tank with JMS. It is dropping from 70psi to 55psi on E40 @ 13.5-14psi of boost at the last 2-300rpm of the gear. He is going to try the LT5 ZR1 pump next which is said to flow another 20%.

Anyway at least lowering the voltage fixed the code. Perhaps you can bump it up to 17.2v and still be ok.

[Joshinator99]

Originally Posted by KingLT1

Seems a bit low but your log that you sent me indicated some odd fuel system fluctuations so I wonder if the low side pump you used has issues?

I would expect to see the LT4 in-tank with JMS go that far if not further on 93. My brother's H/C 2300 C7Z is still running the OE in-tank with JMS. It is dropping from 70psi to 55psi on E40 @ 13.5-14psi of boost at the last 2-300rpm of the gear. He is going to try the LT5 ZR1 pump next which is said to flow another 20%.

Anyway at least lowering the voltage fixed the code. Perhaps you can bump it up to 17.2v and still be ok.

King, I agree 100%. I don't think this DW400 is outperforming the LT4 in tank, at all. Time to go back to the drawing board...