Troubleshoot My Gs

[sebastian0622]

Just bought a '93 GS 300. Got it home, tossed a can of Seafoam in the gas tank and washed the filthy engine bay. At least one of those was a mistake. At least in the short-term.

When I started it up the day after doing this, it idled really rough and blew out white smoke. I figured this was the Seafoam working and burning out some gunk. The more I think about it, the more I think that Seafoam in the fuel shouldn't be that aggressive, so maybe it was water being steamed out. Not good news, obviously, if that's the case. I covered the electrical components with plastic bags before cleaning the bay but water could have gotten in around the plugs. I learned too late that these cars have problems with that.

Anyway, at this point, it will start if I let it set for a few hours. It will idle (again, roughly). No more white smoke. If I rev it up past ~2500, it will smooth out and keep running as long as I keep the RPMs up. If I try to shift to drive or if I let it idle without throttling for a few minutes, it will stall. Then it won't start again for a few hours. If I try, it will crank and kind of chug roughly around 200 - 300 RPM for a few seconds, then die.

Checked the TB, pretty clean. PCV line is intact. Changed the fuel filter and still no luck. Check engine light is not on, and jumping the diagnostics box doesn't make the light flash a code to me.

Ideas on where to go from here?

[sebastian0622]

Anybody have an idea? I'm thinking maybe I should clean the throttle position sensor and the IAC valve. Or it could be the EGR. I'm kind of at a loss, honestly.

[dcfish]

Anybody have an idea? I'm thinking maybe I should clean the throttle position sensor and the IAC valve. Or it could be the EGR. I'm kind of at a loss, honestly.

Here are a the TPS specs: Have you tried drying out the engine bay with compressed air or even an leaf blower ? Maybe water got in a connection somewhere. If you can take the TB off and inspect the plugs for pooling of water on the head They are kind of deep in there and do not dry out easily by themselves. Seafoam shouldn't cause the symptoms that you describe. Are you able to take it out on the highway and run it for a while to heat up everything under the hood and dry it out ? Let us know Also just replace the PCV valve, They are inexpensive. Another thought, You may have fouled a O2 sensor with the seafoam and the ECU has not cycled to throw a CEL.

throttle_position_sensor_GS.pdf

[sebastian0622]

Anybody have an idea? I'm thinking maybe I should clean the throttle position sensor and the IAC valve. Or it could be the EGR. I'm kind of at a loss, honestly.

Here are a the TPS specs: Have you tried drying out the engine bay with compressed air or even an leaf blower ? Maybe water got in a connection somewhere. If you can take the TB off and inspect the plugs for pooling of water on the head They are kind of deep in there and do not dry out easily by themselves. Seafoam shouldn't cause the symptoms that you describe. Are you able to take it out on the highway and run it for a while to heat up everything under the hood and dry it out ? Let us know Also just replace the PCV valve, They are inexpensive. Another thought, You may have fouled a O2 sensor with the seafoam and the ECU has not cycled to throw a CEL.

Thanks for the response. I pulled a plug out and it looks ok. No water pooled up on top of the plugs. I could leave one out and see what it kicks up at me when I try to start it.

Can't get it on the highway because I can't get it into D. It dies as soon as I try to shift it.

I was thinking about a bad O2, but there are so many of them, and they aren't cheap, so I want to move on to that possibility last.

Where is the PCV located? It doesn't seem to be in an obvious spot up top, or else I'm looking right at it and not seeing it. Maybe the passenger side of the engine, where the line runs to the intake?

[dcfish]

Anybody have an idea? I'm thinking maybe I should clean the throttle position sensor and the IAC valve. Or it could be the EGR. I'm kind of at a loss, honestly.

Here are a the TPS specs: Have you tried drying out the engine bay with compressed air or even an leaf blower ? Maybe water got in a connection somewhere. If you can take the TB off and inspect the plugs for pooling of water on the head They are kind of deep in there and do not dry out easily by themselves. Seafoam shouldn't cause the symptoms that you describe. Are you able to take it out on the highway and run it for a while to heat up everything under the hood and dry it out ? Let us know Also just replace the PCV valve, They are inexpensive. Another thought, You may have fouled a O2 sensor with the seafoam and the ECU has not cycled to throw a CEL.

Thanks for the response. I pulled a plug out and it looks ok. No water pooled up on top of the plugs. I could leave one out and see what it kicks up at me when I try to start it.

Can't get it on the highway because I can't get it into D. It dies as soon as I try to shift it.

I was thinking about a bad O2, but there are so many of them, and they aren't cheap, so I want to move on to that possibility last.

Where is the PCV located? It doesn't seem to be in an obvious spot up top, or else I'm looking right at it and not seeing it. Maybe the passenger side of the engine, where the line runs to the intake?

You might be able to clean the O2 sensors (be careful, Don't use anything abrasive, Maybe some alcohol ) Here are some pic's of the PCV, Drivers side of the head near the firewall.

[mlgs300]

Could be an air leak. You won't notice as much at high rpm because it's dumping more fuel into the TB to compensate. Try sparying carb cleaner around vacuum hoses, throttle body, intake, etc. Go to advance auto parts or similar and they'll let you borrow a code reader usually for free. See if you can get any codes out of it like O2 sensors reading lean or rich stuff like that.

[dcfish]

Could be an air leak. You won't notice as much at high rpm because it's dumping more fuel into the TB to compensate. Try sparying carb cleaner around vacuum hoses, throttle body, intake, etc. Go to advance auto parts or similar and they'll let you borrow a code reader usually for free. See if you can get any codes out of it like O2 sensors reading lean or rich stuff like that.

Yes, That could also be the problem, Good thinking

[sebastian0622]

What would be the purpose of the carb cleaner around the vacuum lines?

btw, I've checked all the vacuum connections that I can find and all seem to be ok. But it could be a small crack that I can't see. So I actually will probably just buy a bunch of line from Napa and replace most of 'em. They're pretty old--probably all original, 15 years old.

[sakataj]

What would be the purpose of the carb cleaner around the vacuum lines?

btw, I've checked all the vacuum connections that I can find and all seem to be ok. But it could be a small crack that I can't see. So I actually will probably just buy a bunch of line from Napa and replace most of 'em. They're pretty old--probably all original, 15 years old.

if u have a vacuam leak when it (the car) inhales the carb cleaner it will rev and you will hear it.....knowing u have a vacumn leak

brian

[sebastian0622]

Cleaned the PCV, took out the first plug, looked at it, cleaned it, it looked ok, just a bit dirty. Everything is dry. Cleaned the TPS.

Now when I let it idle, it seems to do so smoothly. It dies basically immediately when I try to give it gas.

I'm going to start it back up and let it idle and see if it dies when it comes up to temp. Then we might be able to narrow it down. Seems like intake air leak of some sort could be the culprit as mlgs said.

Thanks for all the help so far, guys. Keep the ideas comin'.

[JENunnez]

How much gas was in your tank when you put the SeaFoam?

Did you put it in first then fill up or last ?

Sound like your running on SeaFoam.

[sebastian0622]

I put it in last. Almost a full tank at about 1 oz Seafoam per gallon of gas.

I could try to toss some more gas in there and try. Between the little driving I did after the full up and changing fuel filters, I have gone through a a few gallons of gas.

On the one hand, I hope that's it. On the other, I hope that's not it. Because I'll feel really stupid.

[sebastian0622]

Ok, added some gas in case it was just running on Seafoam, shook up the car a bit (rear shocks are in good shape, by the way), let it sit for a few hours and fired it back up. Didn't touch anything after it fired up. It idled really smoothly for about 30 seconds to a minute, then it just died.

Not sure if that info gets us any further on this mystery...

[sebastian0622]

I plan to test the throttle position sensors, but doesn't the car have to be running to do that? I can't keep it running very long at all, so I'm not sure if I'll be able to calibrate them.

[Lexus GS430 Guzzler]

oxygen issue. Probably O2 sensors.

[JENunnez]

Well there was a minute of hope there.

Like DC said there still may be water somewhere in there in one of the electrical connections.

[sebastian0622]

If there was a problem with an O2, would it make sense that it idles fine cold but dies when warmed up or when the gas is pressed?

[jromano]

Check all the spark plugs. It's possible that only a couple are wet.

[sebastian0622]

Check all the spark plugs. It's possible that only a couple are wet.

Ha, funny that I read that now. You're the winner. The front two were dry, but the back one was soaked and both middle ones were soaked. Looks like there are three different "compartments" where water can get in on top of the plugs. In addition, one of the wires is in pretty bad shape.

New wires, plugs, and plenum gasket are on order. I'm pretty sure that's it. Didn't see any water in the chamber so hopefully I didn't damage anything starting it up those times.

[dcfish]

Check all the spark plugs. It's possible that only a couple are wet.

Ha, funny that I read that now. You're the winner. The front two were dry, but the back one was soaked and both middle ones were soaked. Looks like there are three different "compartments" where water can get in on top of the plugs. In addition, one of the wires is in pretty bad shape.

New wires, plugs, and plenum gasket are on order. I'm pretty sure that's it. Didn't see any water in the chamber so hopefully I didn't damage anything starting it up those times.

Hey, I mentioned that in my first post B) :whistles:

[sebastian0622]

Might have a big problem. I noticed two small holes on the exhaust side of the block. I've got some oil coming out of one of 'em. Never seen that on a car before, but it looks like I threw something right through the engine block. Damnit.

[sebastian0622]

Yep, have those two holes right above the exhaust manifold. Puffing a good bit of white smoke out of the tailpipes and idling a little off. Probably threw a freakin' piston ring chunk through the side of the block and ruined the head gasket by compressing water.

Can't think of anything else it could be. Let me know if you have any ideas. Or let me know what my engine swap options are (and a good shop to do it for me in Iowa).

[sebastian0622]

Ok, I can't quite pronounce this thing dead. There is a glimmer of hope. Like I said, there are two pinholes on the side of the block, right above the exhaust manifold. Something must have been thrown right through there on the way out. Hopefully not an internal engine component. But maybe not, just maybe it was something else that got in there, and I can just patch it up and call it a day (quicksteel will do anything). Crazy as that sounds--it can work IF it was a one-time freak thing. Then I could run the crap out of it for as long as I can instead of completely losing my @$$ on it, which I'm looking at doing if I get rid of it now. If I'm looking at a complete engine swap anyway, then why not?

Here's the thing: the car runs pretty well, actually, with the exception that it is running VERY rich. I realized that I'm not puffing any white smoke any more (and what I did puff could have been the result of other things, as I had the TB off, cleaned it, had all the plugs out, had a little residual moisture left, have seafoam mixed in the tank, etc.). I am, however, puffing a steady stream of blackish smoke. It doesn't smell like rotten eggs--it smells like fuel. It's just gas.

A mechanic fridn of mine came over and did plugs and wires on it last week when I was busy. He's done a lot of work for me in the past and knows the Toyota 3.0 very well, so I doubt he screwed anything up. Maybe I should check the gaps--but I don't think something that simple would cause it to run this rich. I already made sure he ran the wires correctly and that all the vac lines were hooked back up.

I don't want to dump a bunch of money into it replacing O2's and whatnot. So I'm thinking that if I don't hear anything obvious from you guys, I'll be taking it to the dealer for diagnostics (unless there is a cheaper alternative to diagnosing it).