Wet distributor?
Thread Starter
Cruising
Joined: Jul 2020
Posts: 10
Likes: 1
Wet distributor?
So I became a happy owner of an 86 Corvette with 76080 miles on Saturday. My mom was all eager to drive it so we spun up the road a short distance even though I have no plates. It started well and purred like a kitten. The car behaved very well the day before when I test drove it. Everything was perfect. Then it rained.
I didn't have a car cover yet (bought one sunday) and I haven't made space in the garage. I didn't think much of it until I went to show my wife the car after the kids went to bed. I turned the key and.... crank crank crank. No start. Needless to say I'm not very happy anymore.
I figure the seal on the cowl between the hood is ancient and may have let water leak onto the distributor. I've purchased a cap and rotor along with wires and the proper plugs (aluminum heads).
I've yet to put the cap and rotor on but I'm really hoping that's the magic ticket. I hate to do the whole distributor so soon. Anyway if you guys have any input I'd appreciate it.
I didn't have a car cover yet (bought one sunday) and I haven't made space in the garage. I didn't think much of it until I went to show my wife the car after the kids went to bed. I turned the key and.... crank crank crank. No start. Needless to say I'm not very happy anymore.
I figure the seal on the cowl between the hood is ancient and may have let water leak onto the distributor. I've purchased a cap and rotor along with wires and the proper plugs (aluminum heads).
I've yet to put the cap and rotor on but I'm really hoping that's the magic ticket. I hate to do the whole distributor so soon. Anyway if you guys have any input I'd appreciate it.
Melting Slicks
Joined: May 2013
Posts: 2,692
Likes: 349
From: Sacramento California
Sounds like you got a good driving car. The common (and correct) response on here is usually "diagnose the problem and find the actual reason" for (in your case) the no-start condition. That seal may be old, but it doesn't mean new ignition parts are the solution. It sucks to buy and install new parts just to find that the problem persists. Also, I get concerned when people start using uncertain terms like, "may have let water leak" and "I'm really hoping." Seen this happen too many times on here -- do a proper diagnosis first. Start by buying a set of 1986 factory service manuals, they run about $100:
1986 Corvette Factory Service Manual
If you take a good look at the distributor and still think water is the culprit, you could remove the distributor cap and give everything a couple shots of WD-40 (water displacer) and see if that helps.
1986 Corvette Factory Service Manual
If you take a good look at the distributor and still think water is the culprit, you could remove the distributor cap and give everything a couple shots of WD-40 (water displacer) and see if that helps.
Thread Starter
Cruising
Joined: Jul 2020
Posts: 10
Likes: 1
DGXR. Fair enough man. I know you are correct that I should have a proper diagnosis. I haven't had the time to dig in and was looking for some short hints for when I get there. I apologize for being out of sequence.
Your WD40 suggestion is precisely what I was looking for. I appreciate that.
I have a FSM on the way. I'm evaluating diagnostic tools as well.
I won't have time to wrench until late Friday or over the weekend so I'm stuck looking at it which is frustrating.
Out of curiosity would it be a bad idea to seal the distributor with silicone?
Your WD40 suggestion is precisely what I was looking for. I appreciate that.
I have a FSM on the way. I'm evaluating diagnostic tools as well.
I won't have time to wrench until late Friday or over the weekend so I'm stuck looking at it which is frustrating.
Out of curiosity would it be a bad idea to seal the distributor with silicone?
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Put a timing light on say #2 wire, hold the trigger and crank the motor to see if it's ignition.
A fuel pressure gauge on the Schrader valve will tell the FP story.
No need to "seal the dist.", IMO. Is the plenum tail piece still attached to shield the dist. top?
A fuel pressure gauge on the Schrader valve will tell the FP story.
No need to "seal the dist.", IMO. Is the plenum tail piece still attached to shield the dist. top?
Safety Car
Joined: May 2001
Posts: 4,755
Likes: 1,644
From: Fairfax Virginia
Does your Corvette still have the extension from the intake Plenum that covers the distributor? It is held on with tiny hardware and covers the distributor well. I would NOT put any silicone on the distributor cap, BAD idea.
After rain I would be more suspicious of wet spark plug wires grounding out on the engine. Using air blow off any water you see and try and run it after it is dried off. Remember this is NOT a British car that stops running when it rains.
Be sure to get a fuel pressure gauge to allow you to be sure that your fuel pump is doing it's job. Next to the Factory Service manuals it is probably the second most important tool to have with a modern Corvette.
After rain I would be more suspicious of wet spark plug wires grounding out on the engine. Using air blow off any water you see and try and run it after it is dried off. Remember this is NOT a British car that stops running when it rains.
Be sure to get a fuel pressure gauge to allow you to be sure that your fuel pump is doing it's job. Next to the Factory Service manuals it is probably the second most important tool to have with a modern Corvette.
Melting Slicks
Joined: May 2013
Posts: 2,692
Likes: 349
From: Sacramento California
I agree, do not seal the distributor. There is a reason why the 1995-1996 LT1 distributors were upgrade with a vent. The constant electrical arcing inside the distributor creates ozone which will corrode and eventually destroy some parts unless the ozone is vented out. So you need some small amount of airflow in the distributor cap.
Thread Starter
Cruising
Joined: Jul 2020
Posts: 10
Likes: 1
I'm not sureven of the frequency of how often it was driven so it might be bad gas. Maybe the rain somehow pooled up and entered the tank because the cap wasn't on all the way. But I think my fuel is compromised and I need to remove it.
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Safety Car
Joined: May 2001
Posts: 4,755
Likes: 1,644
From: Fairfax Virginia
Hello again Stripped Nut!
You can siphon out a lot of it with a good siphon hose setup. I too leave my tanks full as it was a common practice on the small piston aircraft I flew. They told me it was to minimize condensation...
Today's gasoline with ethanol is junk. It has a much shorter shelf life and absorbs water every chance it gets. I drained mine out when I was ready to restart the Corvette after a few months. I drained out as much as I could and then filled it with good fresh gasoline and then removed the fuel filter. I turned the key on to let the system try to pressurize and to blow out the remaining bad gasoline into a gallon bottle. After it was flushed I installed a new fuel filter and started it up.
Good point about the Rain Drain near the gas cap. I have had to unplug my little rubber hose/drain tube several times to keep it clear. If the cap was left loose that would be a great way for water to enter the fuel tank.
If you are going to leave oxygenated gasoline in your Corvette for more than a month be sure to put an ethanol neutralizing additive in the gasoline to help it last longer.
Good Luck, you are getting there!
You can siphon out a lot of it with a good siphon hose setup. I too leave my tanks full as it was a common practice on the small piston aircraft I flew. They told me it was to minimize condensation...
Today's gasoline with ethanol is junk. It has a much shorter shelf life and absorbs water every chance it gets. I drained mine out when I was ready to restart the Corvette after a few months. I drained out as much as I could and then filled it with good fresh gasoline and then removed the fuel filter. I turned the key on to let the system try to pressurize and to blow out the remaining bad gasoline into a gallon bottle. After it was flushed I installed a new fuel filter and started it up.
Good point about the Rain Drain near the gas cap. I have had to unplug my little rubber hose/drain tube several times to keep it clear. If the cap was left loose that would be a great way for water to enter the fuel tank.
If you are going to leave oxygenated gasoline in your Corvette for more than a month be sure to put an ethanol neutralizing additive in the gasoline to help it last longer.
Good Luck, you are getting there!
Thread Starter
Cruising
Joined: Jul 2020
Posts: 10
Likes: 1
I opened both fuel lines at the filter and the adjacent return line and drained as much as I dared by actuating the pump by providing B+ to the G pin. It was pretty low and I let it drip until it stopped.
I buttoned up the fuel lines and checked for leaks. After that I added about 3 to 4 gallons of gasoline and half a bottle of heet. I cranked it but got nothing so I stimulated the pump for a few seconds and tried again. It started hard. You could hear it trying to fire but it resisted until finally the engine was running again. It ran poorly having an obvious misfire. It was easily detected in the exhaust pulse and also vibrated the car. After I revved it to about 1500 and let off it would stumble and stop.
I had changed the plugs and wires and did them one at a time. It's possible I didn't seat a wire properly but I think the misfire is because water still remains in the tank. I'm not sure if I should repeat what I did and remove the fuel again or add more and try to dilute the water.
It's frustrating because the car ran well before this and I don't want to ruin it fighting this uphill battle and finding myself at the base of a learning curve.
I buttoned up the fuel lines and checked for leaks. After that I added about 3 to 4 gallons of gasoline and half a bottle of heet. I cranked it but got nothing so I stimulated the pump for a few seconds and tried again. It started hard. You could hear it trying to fire but it resisted until finally the engine was running again. It ran poorly having an obvious misfire. It was easily detected in the exhaust pulse and also vibrated the car. After I revved it to about 1500 and let off it would stumble and stop.
I had changed the plugs and wires and did them one at a time. It's possible I didn't seat a wire properly but I think the misfire is because water still remains in the tank. I'm not sure if I should repeat what I did and remove the fuel again or add more and try to dilute the water.
It's frustrating because the car ran well before this and I don't want to ruin it fighting this uphill battle and finding myself at the base of a learning curve.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Tank
Some years ago on this forum, there was a guy that had the same problem you’re having.
if you open the gas door and look down, you will see a drain hole. It is holding onto a drain tube that is maybe a foot long.
it’s a great place for bugs to make a home in, and clog it up.
the other guy with your problem Had for some unforeseen reason got a leaf in the gas door, and it sealed off the drain in a rain storm.
the gas cap is made to hold pressure.
it is not made to hold vacuum.
So, when the rain happened, the hot fuel in the tank cooled off and created a vacuum.
that in turn sucked about a quart of rainwater and dirt into his tank.
so check it out.
Run a coathanger down the tube.
just the straight part.
if you succeed in pushing the tube off the drain, just take the license plate off and poke it back on.
Good luck
if you open the gas door and look down, you will see a drain hole. It is holding onto a drain tube that is maybe a foot long.
it’s a great place for bugs to make a home in, and clog it up.
the other guy with your problem Had for some unforeseen reason got a leaf in the gas door, and it sealed off the drain in a rain storm.
the gas cap is made to hold pressure.
it is not made to hold vacuum.
So, when the rain happened, the hot fuel in the tank cooled off and created a vacuum.
that in turn sucked about a quart of rainwater and dirt into his tank.
so check it out.
Run a coathanger down the tube.
just the straight part.
if you succeed in pushing the tube off the drain, just take the license plate off and poke it back on.
Good luck
Last edited by coupeguy2001; Jul 21, 2020 at 12:35 AM.