OG Dada

iTrader: (10)

Hey fellas! I just got my SC300 back on the road after 3 weeks of waiting for parts and not getting enough time to fix it back up. I did not intend on doing a tune-up on it at first, before I saw the condition of the parts. Initially I was just gonna fix a couple of oil leak it had from the distributor o-ring and the valve cover gaskets. Once I disassembled everything, there was no way I was gonna return some of the parts I saw. So, I had to order all ignition parts and wait a week for them to arrive.

The distributor rotor was pretty bad, it had literally chunks of it missing where it's supposed to come contact with the terminals on the cap. The spark plug valley was flooded, and I mean flooded with oil, and it took me about a week to dry that thing up. Spark plug wires have been chewed up here and there by rats. PCV was leaking oil into the intake. I just had to do everything. Changed the spark plugs, spark plug wires, valve cover gaskets, distributor rotor and cap, changed out all vacuum lines to really good looking silicone hoses since I ruined most of them from disassembly, and cleaned the intake from the oil that got in it from the PCV.

Now, I was able to assemble everything to the best of my knowledge. The vacuum lines gave me a hard time figuring out where every one goes. Didn't really expect that to be honest. The diagram on the hood was of no help at all. Very hard to understand. I test drove my SC around town, and after an hour of rest, the Check Engine Light lit up. I wouldn't be able to check for codes until tomorrow. But one thing I noticed is that my very high idle is still there. I thought it might've been just because of the badly needed tune-up. But it still idles at 1600-1800rpm. I couldn't find the correct specs for the throttle position sensor on my repair manual for an SC300. I also have a 96 so I'm not sure if it would have the same specs as pre-OBD2. If anyone have this info please help a brother out.

I'll update with the CEL codes soon as I get to check it tomorrow. Also, if anybody can post actual pics of the vacuum lines routing that would be of great help just so I can verify I did it right. Car runs fine by the way. No hesitation, no loss of power or anything. Thanks.

Maserati

iTrader: (1)

Hey phil, did you see this diagram? im not sure if it will help. You'll have to work backwards.
https://skydrive.live.com/redir?resi...nt=file%2c.pdf

OG Dada

iTrader: (10)

Thanks for the link Maserati, it's not complete though. Any chance I can download that entire document? It looks like it's the correct repair manual for my year SC. Thanks.

1JZPWRD

iTrader: (59)

I am betting that you have the TPS is out of whack or the actual throttle body may have some build up on it. I would clean it on both sides really good and re-evaluate.

OG Dada

iTrader: (10)

Here's the deal, I was so afraid of what might've happened to it after I cleaned it, 'cause I didn't see that there's this one hole that goes straight to the TPS. And I cleaned the entire throttle body with gasoline and degreaser. Not sure if I damaged anything on there, but I've had the high idle even before the tune-up. Also, I noticed, that when I press on the screw that's outside the TPS, it doesn't go all the way down with the throttle, and that's when the idle goes down to somewhere in the 800 rpm range which is still a bit too high for A/C being turned off. Would you be able to post a screen capture of the TPS settings for now so I can set it right? Thanks!

OG Dada

iTrader: (10)

The codes I'm getting are P0300, P0301, P0302 and P0304. It's weird that I'm getting misfire codes but the engine is running perfect. Even idles perfect aside from idling too high. Could the vacuum lines being misrouted cause misfire codes? Can anybody please post a pic of their vacuum lines? My SC is a 96, not sure if the OBD2 is different. TIA

OG Dada

iTrader: (10)

I checked and rechecked my vacuum lines and they seem to be in proper order, so I'm crossing that out. I've been driving the SC for couple of days now, and all of a sudden check engine light comes back on while I'm driving. Anybody have any idea what's going on with my SC?

Vwpride12

sounds like a vacuum leak. I would take some brake clean and spray it around the intake manifold and see if the idle changes.

SC400slide

iTrader: (11)

You said you had the high idle before the tune up? Everything else is a different issue...maybe. If your ECU hasn't been touched, a leaky capacitor could easily cause a high idle. I'm sending my ECU in today and that is one of the symptoms.

OG Dada

iTrader: (10)

I can't really say it has gone that far. Cause lately the idle has been going down around 800rpm. I think I just need to adjust something or clean something like the idle control valve. Nevermind the check engine light, its just the TPS being out of setting. I'm gonna adjust that again anyways. Can someone tell me where is the TPS on the 300 is?

OG Dada

iTrader: (10)

Need some help from anyone who has dealt with my problem! Haven't really had time to work on my SC in a while. Here's what's going on:

I have a problem with high idle. It's better than before, my SC doesn't idle at 1800rpm anymore, but it's still high. Right now, it's idling steady at 1000rpm with or without the A/C on. All vacuum and ventilation lines are already new and have already been replaced. I don't know where else to look.

I randomly get these 3 codes altogether without any symptoms: P0300, P0301, P0302 and P0304.

I need to adjust the throttle position sensor back to spec but I can't find any info on spec for an OBD2. I don't know if I can use the same specs from the SC400 or SC300 OBD1 engines. And I'm getting P0510 because of that.

Any help is appreciated. Thanks!