89 SC Help

smcb · 06-22-2009, 03:56 PM

ok, my 89 sc has been sitting in the driveway for nearly two years now, and I need to get off my ass and fix it.

The problem was that the compression in the two outer cylinders was slowly decreasing, to the point where it almost wouldnt run any more.

I've never torn in to an engine before, so I'm looking for advice on where to start, what could be the issue, etc.

I'm going to dig out my BGB and start reading through that too.

Raptor13x · 06-22-2009, 04:44 PM

What do you have in the way of tools?

palos · 06-22-2009, 07:30 PM

My initial thought was to perform a compression test and/or leak down test, but I doubt that you have a charge in the battery. Also, since the engine hasn't turned over for two years, the piston rings are likely sticky. So, I'd pour a bit of oil in each cylinder and let it sit for a few days to try to free up the rings. You may want to re-install the plugs. At the same time get your battery tested and charged if it is still good. Consider whether the gas tank needs to be drained or if fresh gas can be added, perhaps with an octane booster.

After a few days, remove the plugs and turn the engine by hand. You'll probably be able to tell the difference in the compression in the two cylinders. Then if it feels good, with the battery charged, turn the engine with the starter, but with plugs removed. Oil may splatter out. Lastly, re-install the plugs and connect the wires, then try to start the engine, but remember you will produce a white cloud until the oil burns from the cylinder. If the engine runs and becomes warm, then you could start with my initial thought and perform a compression test to diagnose the problem.

Papo J · 07-02-2009, 12:12 PM

Do a compression test, it sounds like it could be a headgasket leak between those two cylinders.

palos · 07-02-2009, 12:48 PM

smcb: "The problem was that the compression in the two outer cylinders was slowly decreasing, to the point where it almost wouldnt run any more."

I partially agree with Papo J, but it would be a very strange head gasket leak between the No. 1 and No. 4 cylinders. Wondering whether smcb has either poor injectors, plugs and/or wires if he thought the "compression in the two outer cylinders was slowly decreasing". That would be a difficult running problem to sense.

If the compression test comes within acceptable limits, test and/or inspect the injectors, plugs, wires, cap and rotor.

mr2tim · 07-03-2009, 10:44 AM

BTW since you have the 88-89 model year you will be happy to know you have a drain plug on the bottom of the gas tank that the 85-86 year cars do not.(Lucky you!)

Pull the plastic belly pans off, under the car, and get that nasty ol deterioating gasoline out of there (1/2 drive socket head fits into the drain plug!)

Me? I betting you have a defective head gasket, installed by a amateur mechanic not familiar with Toyota cyl head torgue patterns and technigues.

Good Luck, be careful with that old gas!

mr2tim

06-22-2009, 03:56 PM	#1 (permalink)
smcb No Skills Join Date: Jul 2006 Posts: 18 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	89 SC Help ok, my 89 sc has been sitting in the driveway for nearly two years now, and I need to get off my ass and fix it. The problem was that the compression in the two outer cylinders was slowly decreasing, to the point where it almost wouldnt run any more. I've never torn in to an engine before, so I'm looking for advice on where to start, what could be the issue, etc. I'm going to dig out my BGB and start reading through that too.

07-03-2009, 10:44 AM	#6 (permalink)
mr2tim SUPERcharZed ToyZ RacZer Join Date: Mar 2008 Location: South Florida Posts: 690 Thanks: 2 Thanked 41 Times in 38 Posts My Google Map iTrader Rating: (2/100% )	Drain that funky 2 yr old gas! BTW since you have the 88-89 model year you will be happy to know you have a drain plug on the bottom of the gas tank that the 85-86 year cars do not.(Lucky you!) Pull the plastic belly pans off, under the car, and get that nasty ol deterioating gasoline out of there (1/2 drive socket head fits into the drain plug!) Me? I betting you have a defective head gasket, installed by a amateur mechanic not familiar with Toyota cyl head torgue patterns and technigues. Good Luck, be careful with that old gas! mr2tim Attached Thumbnails

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06-22-2009, 04:44 PM	#2 (permalink)
Raptor13x Legendary Join Date: Apr 2006 Location: Farmington Hills, MI Posts: 3,989 Thanks: 7 Thanked 40 Times in 34 Posts My Google Map iTrader Rating: (5/100% )	What do you have in the way of tools?

06-22-2009, 07:30 PM	#3 (permalink)
palos … Join Date: Apr 2009 Posts: 170 Thanks: 0 Thanked 20 Times in 18 Posts iTrader Rating: (0/0% )	My initial thought was to perform a compression test and/or leak down test, but I doubt that you have a charge in the battery. Also, since the engine hasn't turned over for two years, the piston rings are likely sticky. So, I'd pour a bit of oil in each cylinder and let it sit for a few days to try to free up the rings. You may want to re-install the plugs. At the same time get your battery tested and charged if it is still good. Consider whether the gas tank needs to be drained or if fresh gas can be added, perhaps with an octane booster. After a few days, remove the plugs and turn the engine by hand. You'll probably be able to tell the difference in the compression in the two cylinders. Then if it feels good, with the battery charged, turn the engine with the starter, but with plugs removed. Oil may splatter out. Lastly, re-install the plugs and connect the wires, then try to start the engine, but remember you will produce a white cloud until the oil burns from the cylinder. If the engine runs and becomes warm, then you could start with my initial thought and perform a compression test to diagnose the problem.

07-02-2009, 12:12 PM	#4 (permalink)
Papo J 6SPD GTE Join Date: Sep 2006 Posts: 189 Thanks: 1 Thanked 19 Times in 18 Posts iTrader Rating: (0/0% )	Do a compression test, it sounds like it could be a headgasket leak between those two cylinders.

07-02-2009, 12:48 PM	#5 (permalink)
palos … Join Date: Apr 2009 Posts: 170 Thanks: 0 Thanked 20 Times in 18 Posts iTrader Rating: (0/0% )	smcb: "The problem was that the compression in the two outer cylinders was slowly decreasing, to the point where it almost wouldnt run any more." I partially agree with Papo J, but it would be a very strange head gasket leak between the No. 1 and No. 4 cylinders. Wondering whether smcb has either poor injectors, plugs and/or wires if he thought the "compression in the two outer cylinders was slowly decreasing". That would be a difficult running problem to sense. If the compression test comes within acceptable limits, test and/or inspect the injectors, plugs, wires, cap and rotor.