What did I do?
Thread Starter
Heel & Toe
Joined: Apr 2017
Posts: 15
Likes: 1
What did I do?
I bought a 1985 Corvette 2 weeks ago with 7500 miles and it ran great.
The former owner died in 2016 so I thought it would be wise to siphon the old gas out that was running just fine and replace with fresh stabilized fuel. I did this last weekend and didn't start the car till today.
It would start up but then die unless I kept the rpms around 3500 to 4000. After it warmed up a little it would idle and stay running but is really running rough.
Any thought's on what I did?
The former owner died in 2016 so I thought it would be wise to siphon the old gas out that was running just fine and replace with fresh stabilized fuel. I did this last weekend and didn't start the car till today.
It would start up but then die unless I kept the rpms around 3500 to 4000. After it warmed up a little it would idle and stay running but is really running rough.
Any thought's on what I did?
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Check fuel pressure first. If there is an AutoZone store near you, they have testers you can "rent" for free (pay a deposit, bring it back in good shape and you get your deposit back). Fuel pressure should be about 40 psi when you turn the ignition to ON. It will drop some over a few minutes. With the engine running, you should see 35-40 psi.
The fuel pump can easily be remove from the top of the tank. The pump assembly has a wire mesh strainer on the pickup tube. The strainer sits in a small "pan" and it could be that the strainer is clogged and there is junk in that small pan. A replacement strainer is cheap and easy to replace.
It would be a good idea to replace the fuel filter. It will be along the frame rail on the passenger side near the starter. Best to do this with a near-empty tank or raise the front of the car as high as you can. Otherwise, you will get gas draining from the line. The fuel pressure regulator could be bad too.
Pull the distributor cap and check the contacts inside the cap and also the rotor. Can't hurt to replace them.
The fuel pump can easily be remove from the top of the tank. The pump assembly has a wire mesh strainer on the pickup tube. The strainer sits in a small "pan" and it could be that the strainer is clogged and there is junk in that small pan. A replacement strainer is cheap and easy to replace.
It would be a good idea to replace the fuel filter. It will be along the frame rail on the passenger side near the starter. Best to do this with a near-empty tank or raise the front of the car as high as you can. Otherwise, you will get gas draining from the line. The fuel pressure regulator could be bad too.
Pull the distributor cap and check the contacts inside the cap and also the rotor. Can't hurt to replace them.
Safety Car
Joined: Aug 2009
Posts: 3,751
Likes: 276
From: Melbourne, Victoria, Australia
I bought a 1985 Corvette 2 weeks ago with 7500 miles and it ran great.
The former owner died in 2016 so I thought it would be wise to siphon the old gas out that was running just fine and replace with fresh stabilized fuel. I did this last weekend and didn't start the car till today.
It would start up but then die unless I kept the rpms around 3500 to 4000. After it warmed up a little it would idle and stay running but is really running rough.
Any thought's on what I did?
The former owner died in 2016 so I thought it would be wise to siphon the old gas out that was running just fine and replace with fresh stabilized fuel. I did this last weekend and didn't start the car till today.
It would start up but then die unless I kept the rpms around 3500 to 4000. After it warmed up a little it would idle and stay running but is really running rough.
Any thought's on what I did?
It should not matter if the tank was emptied, i usually turn ignition on a few seconds then off and repeat to prime the fuel rails.
Check the vacuum hose that is connected from the inlet manifold vacuum to fuel pressure regulator. It should be dry ... no fuel.
The FPR diaphragm can split, however unlikely.
If there is gas in the vacuum hose replace the FPR and drain oil and replace, the gas will fill the sump if the FPR diaphragm split.
Sometimes disconnecting the battery or ECM connector near battery and reconnecting will allow the engine to run correctly.
Good luck
Thread Starter
Heel & Toe
Joined: Apr 2017
Posts: 15
Likes: 1
problem solved
FYI, it had nothing to do with me siphoning out the old gas.
Turned out to be the MAF air flow sensor.
Man my vette starts up as soon as I turn the key now.
I found a NEW Bosch sensor on eBay for $109 if you need one
http://www.ebay.com/itm/1985-Corvett...53.m2749.l2649
Turned out to be the MAF air flow sensor.
Man my vette starts up as soon as I turn the key now.
I found a NEW Bosch sensor on eBay for $109 if you need one
http://www.ebay.com/itm/1985-Corvett...53.m2749.l2649
Le Mans Master
Joined: Feb 2000
Posts: 9,061
Likes: 214
From: Epping NH
1985 Corvette with 7500 miles, that's impressive, just worry about seals being dry, but she must look great inside! Got any pics?
Don't let the car sit, drive it and enjoy it...can never understand why people save their vettes for someone else to enjoy?!?! Unless there is something unique about the car it's just throwing money away by letting it sit.
Don't let the car sit, drive it and enjoy it...can never understand why people save their vettes for someone else to enjoy?!?! Unless there is something unique about the car it's just throwing money away by letting it sit.
Thread Starter
Heel & Toe
Joined: Apr 2017
Posts: 15
Likes: 1
1985 Corvette with 7500 miles, that's impressive, just worry about seals being dry, but she must look great inside! Got any pics?
Don't let the car sit, drive it and enjoy it...can never understand why people save their vettes for someone else to enjoy?!?! Unless there is something unique about the car it's just throwing money away by letting it sit.
Don't let the car sit, drive it and enjoy it...can never understand why people save their vettes for someone else to enjoy?!?! Unless there is something unique about the car it's just throwing money away by letting it sit.
I bought the car on eBay from a Scottsdale repair shop who was selling the collection for the family. The collection included a 2016 Z06 w/ 460 miles and a 2012 anniversary.
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Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
Great car- well done.
Double check those tires please as they look like the original Gatorbacks. They WILL come apart on you if try to drive them anywhere other than a tire store.
Keep your fenders intact!
Double check those tires please as they look like the original Gatorbacks. They WILL come apart on you if try to drive them anywhere other than a tire store.
Keep your fenders intact!
Thread Starter
Heel & Toe
Joined: Apr 2017
Posts: 15
Likes: 1
Le Mans Master
Joined: Jan 2006
Posts: 5,621
Likes: 206
From: Orlando FL
If the tires are over 6 years old they will not be any good for high speed driving on the expressway. The heat where you live on an older tire will take it apart. Check out the year made on the tire year code, tread does not matter how good it is.
Living in central FL and having been out to Scottsdale many times I know something about heat. Up north you can go 7 years on the tires.
Living in central FL and having been out to Scottsdale many times I know something about heat. Up north you can go 7 years on the tires.
Thread Starter
Heel & Toe
Joined: Apr 2017
Posts: 15
Likes: 1
If the tires are over 6 years old they will not be any good for high speed driving on the expressway. The heat where you live on an older tire will take it apart. Check out the year made on the tire year code, tread does not matter how good it is.
Living in central FL and having been out to Scottsdale many times I know something about heat. Up north you can go 7 years on the tires.
Living in central FL and having been out to Scottsdale many times I know something about heat. Up north you can go 7 years on the tires.
2 weeks ago we had our first really high temps (120) hit Phoenix.
Had a car on the freeway blow a tire right in front of me on the freeway.
Blown tires all over the roads. Tow trucks were very busy.
Le Mans Master
Joined: Dec 2005
Posts: 8,576
Likes: 963
From: Communist Colorado
I actually had that car on my Ebay watch list when it was for sale... I see the brake m/c looks a little dark in color in the reservoir. I would probably dump the fluid and check the rubber brake hoses etc. I wound up buying an 86 with 34k on it and had to go through the brakes,,, M/C, hoses, Pads, a full removal and cleaning of the calipers as well as a full fluid flush. Nice looking ride!!