Rough running 89 Carrera after being parked 6 months....possible cause?

[Mike Kunz]

After many years of never ever having an engine running issue, I started my 89 Carrera for the first time in about 6 months and while she fired right away....there's no power (I did not drive the car), the engine idles roughly and takes accelerator input poorly. Not the free revving I am used to. Never had an issue with this, so I am wondering? 6 months ago, plugs were changed, oil change, etc. and the car ran great. It's almost like it's only running on 3 cylinders...not sure.

The tank is about ¾ full. Battery was dead, new one installed tonight.

So, any clues? Fuel, plugs fowled, ignition? What to check first?

Any guidance would be appreciated!

Thanks!

Mike

[Noah930]

Gasoline isn't meant to sit around for 6 months. It separates, varnish develops on the fuel injection parts, etc. If everything else looks OK (battery, plugs, fuses/relays, etc) then see what happens if you drain out the tank and put in fresh fuel.

[Hugh R]

Cheap CA gas is my guess, lots of ethanol which evaporates and leaves gum. My Honda generator and my ECHO weed wacker suffer from the same affliction. Run it and dump some Techron in it. I "try" and at least start my Targa once every two weeks, whether I drive it or not, to at least run some fuel through it. Same with my RV.

But my 84 just failed SMOG as a GROSS POLLUTER, so I'm no expert.

[dshepp806]

I'd drain the fuel tank and load fresh gas with a healthy dose of Techron or BG44k.


Doyle

[Lapkritis]

6mos... Check for rodents. Otherwise top up the fuel. Next time parked more than 45 days you should put in gas stabilizer with a full tank of fuel.

[targa80]

Six months is plenty of time to build a nice home, have you checked your air intake?

[Kevin911sc]

Ethanol....I had a similar issue, Added a bottle of redline SI-1 fuel system cleaner and it fixed her right up...plus its a upper cylinder lubricant so adding a little to each tank of gas will protect you against cheap gas.

[CCM911]

I don't really believe that fuel goes bad within a year. I have had gas in my tank for much longer, and never had any issues. But maybe I am just lucky.

But I do agree with Noah's suggestion. Although, I don't think it was due to bad gas, rather, I think you got some water in your fuel due to condensation from temperature changes.

But before I would go through all that trouble, pop the distributor cap and make sure everything is dry in there. You may get lucky.

Originally Posted by Noah930

Gasoline isn't meant to sit around for 6 months. It separates, varnish develops on the fuel injection parts, etc. If everything else looks OK (battery, plugs, fuses/relays, etc) then see what happens if you drain out the tank and put in fresh fuel.

[rick-l]

injectors may be stuck

[Lapkritis]

Originally Posted by rick-l

injectors may be stuck

^x2

If you have an infrared thermometer then you could check each exhaust runner. Find a cold cylinder, check the spark plug. If it's stuck then you can lightly tap on the body with the engine idling which sometimes can un-stick them. Probably a good idea in that situation to run injector cleaner through... Techron, Lucas, STP, Marvel etc. Choose your snake oil wisely.

[Flat Six]

Originally Posted by CCM911

I don't really believe that fuel goes bad within a year. I have had gas in my tank for much longer, and never had any issues. But maybe I am just lucky.

CM, I've experienced the same thing the OP has; I'm convinced it's partly due to the change in gasoline formulations (2X per year) we get here in the People's Republic. Something to do with evaporative losses and air quality, I believe. The 'winter' formulation that's likely in the OP's tank behaves/evaporates differently in the 90F+ weather we're experiencing here now. No evidence, but I'd think this combination makes it more likely that OP is experiencing gumminess in his fuel system.

BTW, when the local refineries slow down/shut down 2X a year to switch processing from one formulation to the other, there's a 'temporary' price hike attributed to restricted supply that somehow magically becomes a permanent price increase.

[CCM911]

Flat Six, you make a good point. The gas in my car was purchased in the summer, so the blend was different.

Thanks so much for the input. And you make me laugh when you call California the "People's Republic".

You need to come visit Pennsylvania one day. It is almost mandatory that you carry a firearm. Not too many gun laws here, LOL.

Originally Posted by Flat Six

CM, I've experienced the same thing the OP has; I'm convinced it's partly due to the change in gasoline formulations (2X per year) we get here in the People's Republic. Something to do with evaporative losses and air quality, I believe. The 'winter' formulation that's likely in the OP's tank behaves/evaporates differently in the 90F+ weather we're experiencing here now. No evidence, but I'd think this combination makes it more likely that OP is experiencing gumminess in his fuel system.

BTW, when the local refineries slow down/shut down 2X a year to switch processing from one formulation to the other, there's a 'temporary' price hike attributed to restricted supply that somehow magically becomes a permanent price increase.

[Flat Six]

Originally Posted by CCM911

Flat Six, you make a good point. The gas in my car was purchased in the summer, so the blend was different.

Thanks so much for the input. And you make me laugh when you call California the "People's Republic".

You need to come visit Pennsylvania one day. It is almost mandatory that you carry a firearm. Not too many gun laws here, LOL.

Next time I'm back there I'll look you up. My dad's family is from the Conestoga area; grandpa worked for the Baldwin Locomotive Works back in the '20s . . .

[theiceman]

Originally Posted by Flat Six

CM, I've experienced the same thing the OP has; I'm convinced it's partly due to the change in gasoline formulations (2X per year) we get here in the People's Republic. Something to do with evaporative losses and air quality, I believe. The 'winter' formulation that's likely in the OP's tank behaves/evaporates differently in the 90F+ weather we're experiencing here now. No evidence, but I'd think this combination makes it more likely that OP is experiencing gumminess in his fuel system.

BTW, when the local refineries slow down/shut down 2X a year to switch processing from one formulation to the other, there's a 'temporary' price hike attributed to restricted supply that somehow magically becomes a permanent price increase.

i was going to suggest this as this is common in Canada . We get about 15 reformulations a year . as we come from extreme heat to extreme cold .. its not so much of bad gas as it is wrong gas.

I did not realize you even reformulate in California so i thought that was not it ..

the sticking injector makes sens though as the stuff in the tip of the injector can gum up after that long.

[wayner]

Lots of people insist that there is nothing wrong with gas after 6 months. In fact lots of people claim not to have suffered any ill effect with storing an engine without stabilizing the fuel, BUT:

Open up a carb that has been put away wet and has had the fuel evaporate, and see what you see in the float bowls!

Anytime I park for a month or more I add stabile or similar product to the tank, and run it long enough to have the mix make its way to the combustion chamber. Otherwise untreated fuel sits in the carb or injectors, causing sticking. Eventually it happens. Each season may close off your orifices just a little bit more.

Drain it (the floats) or bleed it (the injection system) or treat it before parking it.

I am less concerned about the gas in the tank since there is such huge volume in comparison to the flats or injectors, although why not just treat it to be safe?

(if that is the cause, you may get lucky by just running a few tanks of high test fuel through it since they are supposed to have some detergents in the ingredients).

[pmax]

Originally Posted by wayner

Lots of people insist that there is nothing wrong with gas after 6 months. In fact lots of people claim not to have suffered any ill effect with storing an engine without stabilizing the fuel, BUT:

I'm no chemist but I would think gas can be left sitting longer in a mild climate area like California vs Canada.

[Bob Kontak]

Originally Posted by Flat Six

Something to do with evaporative losses and air quality, I believe.

+1

Winter gas has more VOC's - Volatile Organic Compounds - It turns to vapor more easily so your engine can pop better on a cold-ass day. If you hypothetically filled your tank in the summer with winter gas the vapors exiting from the tank on fill up would be way more than less volatile summer gas.

For the chemists, the term is RVP - Reid Vapor Pressure. Some kind of test where they measure the VOC's. So the gas will have an RVP of XX.