Left car outside- Now Violent surging and miss- Runs terrible
01-10-2018, 01:27 PM
#1
Safety Car
Thread Starter
Left car outside- Now Violent surging and miss- Runs terrible
Left the car outside for a week. It rained. Its a 98 MN6. This car runs Terrible. I changed the spark plug wires. Inspected the Mass air flow. Pulled codes and there were No codes.
Got any idea on which direction I should look next?
Got any idea on which direction I should look next?
01-10-2018, 03:20 PM
#2
Safety Car
Thread Starter
I used the cars built in reader. But I'm about to try a handheld.
01-10-2018, 05:43 PM
#3
Safety Car
Thread Starter
Hand held readers are a waste of time. They only see the standardized emissions codes and NOT the hundreds of C5 unique codes that can be set.
Interesting if not hard to believe that there were no codes set yet you feel there was surging and engine misses occurring........
Is the carpet in the passenger foot well wet???
The BCM and IPC fuse box are both located at floor level behind the toe kick. Either or both of those could have gotten wet if the wiper well udders are plugged up and the rain water backed up into the foot well:
https://www.corvetteforum.com/forums...ak-checks.html
Interesting if not hard to believe that there were no codes set yet you feel there was surging and engine misses occurring........
Is the carpet in the passenger foot well wet???
The BCM and IPC fuse box are both located at floor level behind the toe kick. Either or both of those could have gotten wet if the wiper well udders are plugged up and the rain water backed up into the foot well:
https://www.corvetteforum.com/forums...ak-checks.html
01-10-2018, 06:06 PM
#4
Safety Car
Thread Starter
But I DO appreciate your willing to help me get through this.
01-10-2018, 06:16 PM
#5
Safety Car
Thread Starter
Says A6-SCN NO COMM. But everything else said NO CODES.
01-10-2018, 06:19 PM
#6
Team Owner
I know this is a longshot, but if your problem isn't electrical, any chance the gas cap is loose, allowing water to splash down into the tank?
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Red5 (01-10-2018)
01-10-2018, 07:42 PM
#7
Le Mans Master
Shot in the dark; do you have an open element filter, stock air box??
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Red5 (01-10-2018)
01-10-2018, 09:27 PM
#8
Safety Car
Thread Starter
01-10-2018, 09:29 PM
#9
Safety Car
Thread Starter
01-11-2018, 12:26 AM
#10
Le Mans Master
I'm thinking there's a chance some water got in, obviously not enough for hydrostatic lock (more water than the cylinder volume at TDC), but enough to be a concern.
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Red5 (01-11-2018)
01-11-2018, 07:54 AM
#11
Team Owner
Just to be sure, I'd get a bottle of "dry gas", at a local auto parts store, and pour it in. If there is water in the tank, this should take care of it. If not, you've lost very little, as well as ruled it out. However, since the Corvette has a pair of "saddle tanks", you'd probably have to let the car run for several minutes, to circulate the dry gas.
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Red5 (01-11-2018)
01-11-2018, 08:00 AM
#12
Team Owner
Another shot in the dark. The early C5's had a bulletin out on water getting under the manifold and shorting the knock sensors. The solution was to build a damn of RTV around the sensor to keep the water out. Can't recall what the symptoms were when this occurred but something to keep in your playbook if you still can't find the issue.
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Red5 (01-11-2018)
01-11-2018, 10:09 AM
#13
Safety Car
Thread Starter
Another shot in the dark. The early C5's had a bulletin out on water getting under the manifold and shorting the knock sensors. The solution was to build a damn of RTV around the sensor to keep the water out. Can't recall what the symptoms were when this occurred but something to keep in your playbook if you still can't find the issue.
FWIW: The car slams on and off when I hit the gas. Or when idling it is Not smooth at all. Whatever is causing this is a a major part of what makes the car run.
Trying to get off work early so that I can dive back into this today.
Thanks again for any help.
01-11-2018, 10:44 AM
#14
Melting Slicks
Check this post and this other one
Last edited by GCG; 01-11-2018 at 11:31 AM.
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Red5 (01-11-2018)
01-11-2018, 01:07 PM
#15
My '98 has sat outside in all weather for 10 years. It runs fine.
I would re-visit the spark plug wires. It's the last thing you touched before it began problems. Always look at the last thing you did.
Check around the spark plugs and maf for unplugged vacuum lines or pulled connectors. Clean your udders.
Don't let wet leaves sit on plastic cars. They etch themselves into the paint.
Hope you find it.
I would re-visit the spark plug wires. It's the last thing you touched before it began problems. Always look at the last thing you did.
Check around the spark plugs and maf for unplugged vacuum lines or pulled connectors. Clean your udders.
Don't let wet leaves sit on plastic cars. They etch themselves into the paint.
Hope you find it.
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Red5 (01-11-2018)
01-11-2018, 01:47 PM
#16
Safety Car
Thread Starter
GOOD NEWS! Or at least somewhat good news. Came home to work on it today. Started the car and it runs Perfect.
No idea as to what it was but for now it falls under the "If it's not broken" philosophy.
If it comes back I will re-start this thread right here. But for now we are good to go.
No idea as to what it was but for now it falls under the "If it's not broken" philosophy.
If it comes back I will re-start this thread right here. But for now we are good to go.
01-13-2018, 11:15 AM
#18
Team Owner
Did you check the passenger's foot well for water intrusion? The udders could be clogged.
Check this post and this other one
Check this post and this other one
01-13-2018, 12:33 PM
#19
Racer
There is a multipin connector on top of each valve cover. Check these connectors for corrosion. This could flair up when you have wet weather.
A very similar problem happened to my '99 and the corrosion was the problem.
A very similar problem happened to my '99 and the corrosion was the problem.