Engine update.
So, when the car failed (in parking lot) their was a large bang and the air intake forward of the mass air flow was broken into about six large pieces, and the entire unit was cracked everywhere. Looking at the fractures it apears that internal pressure caused it to break. I tried to start the car, but it would not crank.
When the dealer got the car they removed the debri from the mass airflow sensor and the car started. It had no abnormal sounds so they went and ordered a complete new air intake, sensors, and a mass air flow unit. The only codes were for the broken sensors and misfire codes. They also said the car was low on fuel.
After putting in the new parts everything seemed fine. No explination as to what happened but they agreed that their was some sort of backfire thru the intake. They ran the car quite a bit in the shop and all was well.
Here is where it gets strange. After driving about 1/4 of a mile the car starts to run rough, seems to be running on 6 cylinders. I happen to be infron of a gas station so I pull in and fill up. The car took just over 16 gallons, so their were just under 2 still in the tank. Start the car back up and it is still running rough. After a couple minutes it seems fine so I head down the road. After about 1/2 mile it starts running SUPER rough, I get a service active handling, ABS failure, and all kinds of warnings on the display along with an engine light. I pull into the restuarant where my wife is waiting and eat dinner.
After dinner I planned to take the car back to the dealer. Much to my surprise it runs perfect so I head home. The next day I take it to the dealer for them to look at it. They run a code scan and the only code is for a misfire. Since picking up the car two days ago I have been about 120 miles with only the above issue.
Before I bought the car in April it had only been 1900 miles in 3-1/2 years. I have put another 4000 on it. Being low on fuel could cause the pump to pick up some junk, but the filter should catch that and the car had been run quite a bit at the shop without issue.
I would like to say GM was extremly helpful. They contacted me thru social media, and gave me frequent updates on my car. Excellent customer service from my perspective.
Scott
Hi there,
Ok, first, lets start with the basics. I see 3 things that make me wonder.
#1, Was a fuel sample taken ????? You had 2 gallons left, which tells me that there is not a low fuel LEVEL problem, but maybe a fuel QUANTITY or QUALITY problem. Ethanol more than 10% can yield drivability issues but certainly not backfiring through the intake. Also, be aware that ethanol encapsulates moisture so adding more drygas can create hesitation and lower power from your engine. The ethanol in the fuel would be enough to take the moisture out of the tank and burn it accurately without issue, UNLESS you got more than a cup or 2 of water.
#2, you stated there was a misfire code. What was the code number? Even if it was a basic P0300 misfire, the misfire DATA within the engine control module will tell you WHICH cylinder was misfiring the most so you can focus on that cylinder. Certainly, I would be very interested in that data. You can reference the picture below to understand the data I speak of.
#3, if you had all those warning lights, THERE WILL BE other codes within the control modules of the Corvette. These codes, while some can overlook, SHOULD ALWAYS be documented and verified. They can give you hints as to where to proceed for diagnostics and point you in a solid direction. NOTE: a misfire can cause a 'service light' although, I would seriously dig deeper here.
A couple of notes from my point of view.
I would be looking at the fuel trim data as well as the information on the misfire data. There is no question that if there is a fuel issue, the fuel trim tables will either be adding or taking away fuel from your engine.
DO NOT DISCOUNT ANYTHING, as this low mileage dictates that nothing be overlooked.
Allthebest, Paul
4LT GS Roadster
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