C6 2005 Won't Hold Idle
02-28-2018, 10:29 AM
#21
Burning Brakes
It looks like you took care of a future potential problem with the coils and wires. You didn't mention the mileage of the car. If it's around 100K a fuel pressure check is not a bad idea. If you have a manual transmission it is not necessary to drop the transaxle and transmission to replace a fuel pump. A dirty throttle body can also cause stalling and drivability issues. Good luck.
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moiboy22 (03-05-2018)
02-28-2018, 10:31 AM
#22
Check your air boot from the air cleaner to the intake manifold. If the boot gets loose, it will send false singles to your MAF and then the engine will run like crap. It could also throw a code "Traction Control". Why does it throw a "traction control" code, I have no idea. But I had the same problem and found the boot had come loose.
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moiboy22 (03-05-2018)
02-28-2018, 09:57 PM
#23
Intermediate
Thread Starter
It looks like you took care of a future potential problem with the coils and wires. You didn't mention the mileage of the car. If it's around 100K a fuel pressure check is not a bad idea. If you have a manual transmission it is not necessary to drop the transaxle and transmission to replace a fuel pump. A dirty throttle body can also cause stalling and drivability issues. Good luck.
02-28-2018, 09:58 PM
#24
Intermediate
Thread Starter
Check your air boot from the air cleaner to the intake manifold. If the boot gets loose, it will send false singles to your MAF and then the engine will run like crap. It could also throw a code "Traction Control". Why does it throw a "traction control" code, I have no idea. But I had the same problem and found the boot had come loose.
02-28-2018, 10:01 PM
#25
Intermediate
Thread Starter
Well, so goes my bet.
Have you checked for any codes?
If not, now's the time.
Guessing (again w/ no assurances) problem may lie w/ MAF, or possibly fuel pump going south. FP failures are not unusual and w/ an '05 especially so.
Hoping it isn't FP.
Replacement requires dropping entire rear end, AT are even a bigger PITA. Both demand beaucoup labor hours.
(IMO one of the glaring design screw-ups for C6 owners while a great profit stream for GM's dealers.)
Since you're in southern CA there're scads of HP shops, many experienced w/ C6, who'd likely do the job for less $ than a dealer, often savings is substantial.
Check the codes first thing, problem & solution may be contained w/in.
If you've no code reader they're not overly expensive, or nearly all parts stores read codes for free as a service to their customers.
Of course, car has to get to a store.
Sorry to hear this, in fact a genuine bummer.
Let's hope one of the forum's big dogs weighs-in, again.
Digging deeper requires more insight than I possess, some of our big dog members earn their living wrenching on C6 et al & usually happy to help w/ where exactly to start if they're aware there's a need.
BTTT the thread for more eyeballs.
Have you checked for any codes?
If not, now's the time.
Guessing (again w/ no assurances) problem may lie w/ MAF, or possibly fuel pump going south. FP failures are not unusual and w/ an '05 especially so.
Hoping it isn't FP.
Replacement requires dropping entire rear end, AT are even a bigger PITA. Both demand beaucoup labor hours.
(IMO one of the glaring design screw-ups for C6 owners while a great profit stream for GM's dealers.)
Since you're in southern CA there're scads of HP shops, many experienced w/ C6, who'd likely do the job for less $ than a dealer, often savings is substantial.
Check the codes first thing, problem & solution may be contained w/in.
If you've no code reader they're not overly expensive, or nearly all parts stores read codes for free as a service to their customers.
Of course, car has to get to a store.
Sorry to hear this, in fact a genuine bummer.
Let's hope one of the forum's big dogs weighs-in, again.
Digging deeper requires more insight than I possess, some of our big dog members earn their living wrenching on C6 et al & usually happy to help w/ where exactly to start if they're aware there's a need.
BTTT the thread for more eyeballs.
I’ll update when I finish cleaning the MAF and throttle body.
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Landru (03-01-2018)
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moiboy22 (02-28-2018)
02-28-2018, 11:32 PM
#27
Intermediate
Thread Starter
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moiboy22 (03-03-2018)
03-03-2018, 12:39 AM
#29
Intermediate
Thread Starter
Still havent had a moment to do the work discussed. One thing I noticed today was the battery dead on the Vette. Or atleast not enough to crank it. (That may be from keeping the hood open while working on it for an extended period of time and the hood light staying on)
03-04-2018, 01:47 PM
#30
Intermediate
Thread Starter
Checked boot, cleaned MAF, cleaned throttle body, checked fuel pressure (plus fuse and relay), cleaned full air intake, put fuel additive (just in case bad fuel. I was seeing white smoke coming from o2 Sensor areas and out of rear) and still same issue.
I did notice that it got mildly better when I disconnected the MAP sensor. Hmm. But not enough to return to normal condition.
I got a fuel pressure gauge from Orileys. I will update with the video from that test. Pressure shakes on idle.
edit: This is the pressure test vid.
Only consistent code is P0300 still. I will update again soon. See video for more details.
I did notice that it got mildly better when I disconnected the MAP sensor. Hmm. But not enough to return to normal condition.
I got a fuel pressure gauge from Orileys. I will update with the video from that test. Pressure shakes on idle.
edit: This is the pressure test vid.
Only consistent code is P0300 still. I will update again soon. See video for more details.
Last edited by moiboy22; 03-05-2018 at 12:28 PM.
03-05-2018, 10:00 AM
#31
Race Director
Checked boot, cleaned MAF, cleaned throttle body, checked fuel pressure (plus fuse and relay), cleaned full air intake, put fuel additive (just in case bad fuel. I was seeing white smoke coming from o2 Sensor areas and out of rear) and still same issue...Only consistent code is P0300 still. I will update again soon.
Went online, found this place: https://www.obd-codes.com/p0300
It said:
"A code P0300 may mean that one or more of the following has happened:
1-Faulty spark plugs or wires
2-Faulty coil (pack)
3-Faulty oxygen sensor(s)
4-Faulty fuel injector(s)
5-Burned exhaust valve
6-Faulty catalytic converter(s)
7-Stuck/blocked/leaking EGR valve / passages
8-Faulty camshaft position sensor
9-Defective computer
1 & 2 probably can be crossed off, but there're 7 other possible sources. Start w/ #3 for elimination & proceed until it gets right.
At link are comprehensive TS steps, one w/ a video + links to many discussions on this P0300 code.
Last edited by Landru; 03-05-2018 at 10:01 AM.
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moiboy22 (03-05-2018)
03-06-2018, 08:01 AM
#32
Race Director
Member Since: Aug 2005
Location: Hudson WI
Posts: 13,598
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NCM Sinkhole Donor
Have you checked the Fuel Pressure? I had a similar issue with another car (not a Corvette) and it was the fuel pump.
Long shot, but I have a 1969 Honda CT90 that would start but die when I tried to ride it and a mouse ate some of the wiring going to the coil. There a are a punch of wires at the back of the engine that feed the coils, may want to check them if you haven't already.
Long shot, but I have a 1969 Honda CT90 that would start but die when I tried to ride it and a mouse ate some of the wiring going to the coil. There a are a punch of wires at the back of the engine that feed the coils, may want to check them if you haven't already.
Last edited by timd38; 03-06-2018 at 08:04 AM.
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moiboy22 (03-06-2018)
03-06-2018, 09:54 AM
#33
Intermediate
Thread Starter
Have you checked the Fuel Pressure? I had a similar issue with another car (not a Corvette) and it was the fuel pump.
Long shot, but I have a 1969 Honda CT90 that would start but die when I tried to ride it and a mouse ate some of the wiring going to the coil. There a are a punch of wires at the back of the engine that feed the coils, may want to check them if you haven't already.
Long shot, but I have a 1969 Honda CT90 that would start but die when I tried to ride it and a mouse ate some of the wiring going to the coil. There a are a punch of wires at the back of the engine that feed the coils, may want to check them if you haven't already.
03-06-2018, 10:01 AM
#34
Intermediate
Thread Starter
Update: I think I have narrowed it down to 3 or 4 things. While working on the car last night I noticed only one side of the exhaust spitting out hot air. The other was cold and then turned mildly warm. Also smelled like eggs so I'm thinking blocked or clogged cat. That or the carb. All 8 cylinders are firing (I checked each) and I noticed smoke coming up from both 02 sensor ports below the 4 spark plugs on each side. Taking it to the shop to get a solid answer and will update when back from the Vette doctor.
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Landru (03-06-2018)
03-06-2018, 03:01 PM
#35
Intermediate
Thread Starter
Update: Took the car into the dealership doctor and there’s good and bad news. Good news is I know what it is. Bad news is I know what it is. They said I broke a valve spring in cylinder 6. Also that one of the springs on cylinder 4 looked bad. I want to do the work myself but need an air compressor and somewhere to plug it in.
I want ant to take it my fav shop (American Heritage) but they are backed up for the week.
I can can get the kit to do it all but I’ve read that if you don’t use an air compressor you could drop a cylinder when compressing the spring and removing the retainer. Is this correct? Also anyone know of places that let folks bum power outdoors?
Thanks all again for your help with this one.
I want ant to take it my fav shop (American Heritage) but they are backed up for the week.
I can can get the kit to do it all but I’ve read that if you don’t use an air compressor you could drop a cylinder when compressing the spring and removing the retainer. Is this correct? Also anyone know of places that let folks bum power outdoors?
Thanks all again for your help with this one.
03-06-2018, 03:46 PM
#36
Race Director
I want to do the work myself but need an air compressor and somewhere to plug it in...I can can get the kit to do it all but I’ve read that if you don’t use an air compressor you could drop a cylinder when compressing the spring and removing the retainer. Is this correct? [b]Also anyone know of places that let folks bum power outdoors?[/b
W/couldn't hurt approaching management, explain the situation.
Ask what they'd charge you for juice to power a small compressor, and, a firm realistic timeframe you'll need to finish job.
Last thing these places want is a vehicle on blocks for weeks on-end.
Same tack applies to any/all friends and/or acquaintances including coworker(s) (if still working) OR someone, anyone they may know who'd be willing to help, here.
Probability for success is higher if asking a pistonhead car lover, too.
Got absolutely nothing to lose, my friend.
There're good people out there still, give 'em a chance to show it by asking.
The Big Problem was ID'g the source of the trouble and you got that.
Heck I'd give you my garage's bay 3 and power, free. Unfortunately, we couldn't live further apart if it were differing planets.
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moiboy22 (03-06-2018)
03-06-2018, 04:08 PM
#37
Race Director
Member Since: Aug 2005
Location: Hudson WI
Posts: 13,598
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NCM Sinkhole Donor
In the future if you want to know if a cylinder is working, get $20 heat measurer at Harbor Freight and if the exhaust is cold on that cylinder, you know it has issues.
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moiboy22 (03-06-2018)
03-06-2018, 04:49 PM
#38
Race Director
03-06-2018, 04:57 PM
#39
Safety Car
Update: Took the car into the dealership doctor and there’s good and bad news. Good news is I know what it is. Bad news is I know what it is. They said I broke a valve spring in cylinder 6. Also that one of the springs on cylinder 4 looked bad. I want to do the work myself but need an air compressor and somewhere to plug it in.
I want ant to take it my fav shop (American Heritage) but they are backed up for the week.
I can can get the kit to do it all but I’ve read that if you don’t use an air compressor you could drop a cylinder when compressing the spring and removing the retainer. Is this correct? Also anyone know of places that let folks bum power outdoors?
Thanks all again for your help with this one.
I want ant to take it my fav shop (American Heritage) but they are backed up for the week.
I can can get the kit to do it all but I’ve read that if you don’t use an air compressor you could drop a cylinder when compressing the spring and removing the retainer. Is this correct? Also anyone know of places that let folks bum power outdoors?
Thanks all again for your help with this one.
Last edited by irok; 03-06-2018 at 05:00 PM.
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moiboy22 (03-06-2018)
03-06-2018, 05:10 PM
#40
Intermediate
Thread Starter
its time with that mileage and your issues to change all the valve springs not just the one that is broken or the one that looks bad.buy a new set from GM plus new seals.not expensive or difficult to do and yes you will drop a valve if you don't pressurize the system while doing the swap
I will try my luck at the job and update on how it goes. I will be swapping out all springs, seals and the gaskets. Fingers crossed! I will update when completed.
Last edited by moiboy22; 03-06-2018 at 05:30 PM.
