93 SC Problems.
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From: Ontario
93 SC Problems.
Alright, before I get started I know a lot of you are going to say "research it" and I want to point out that I have.
My 93 Sc400 (approx 301,000 km) is taking a dive for the worst. Whenever I go to start it, the idle is all choppy, and I can't get it past 1200-1500 RPM. When it goes any higher it completely bogs out. almost like a fuel cut?
Now, a lot of places said to clean the IACV, so I did. I changed sparks (that helped with a misfire, was running on 5-6 cyl's) changed oil, MAF is fine, no leaks from airbox, cleaned the manifold, spark wires are fine... I'm almost at a loss. And to boot it has a throttle lag, and it feels as if it doesn't have as much power as it should.
I'm stumped, could it be the ECU, and if it is, could I just get another from the same year SC and plug-n-play, or would it need a retune at lexus?
Shoot me your ideas! I'm at a loss and would greatly appriciate it!
My 93 Sc400 (approx 301,000 km) is taking a dive for the worst. Whenever I go to start it, the idle is all choppy, and I can't get it past 1200-1500 RPM. When it goes any higher it completely bogs out. almost like a fuel cut?
Now, a lot of places said to clean the IACV, so I did. I changed sparks (that helped with a misfire, was running on 5-6 cyl's) changed oil, MAF is fine, no leaks from airbox, cleaned the manifold, spark wires are fine... I'm almost at a loss. And to boot it has a throttle lag, and it feels as if it doesn't have as much power as it should.
I'm stumped, could it be the ECU, and if it is, could I just get another from the same year SC and plug-n-play, or would it need a retune at lexus?
Shoot me your ideas! I'm at a loss and would greatly appriciate it!
Thread Starter
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Joined: Dec 2012
Posts: 54
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From: Ontario
And no there is no CEL on, and according to a mechanic I brought it to before it wasn't throwing any codes.
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Search the SC300 DIY fuel mod in the search bar. This has been proven over and over to improve similar problems that you are experiencing. It might work, might not. I would also look at both coils, and both igniters.
Will try the 12V mod, found it yesterday.
I think next on the list is coils, like Mark suggested. While at idle, unplug the drivers side coil. (or pssnger side). If there is a change in idle, it is most likely good. But if there in no change whatsoever, the coil is bad. Try both and see what coems up!
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From: Ontario
The 12v Mod is to bypass the Fuel ECU. If your friends ECU worked correctly, and it didn't correct your SC issues, then the 12v mod will not do anything...at least, not much.
I think next on the list is coils, like Mark suggested. While at idle, unplug the drivers side coil. (or pssnger side). If there is a change in idle, it is most likely good. But if there in no change whatsoever, the coil is bad. Try both and see what coems up!
I think next on the list is coils, like Mark suggested. While at idle, unplug the drivers side coil. (or pssnger side). If there is a change in idle, it is most likely good. But if there in no change whatsoever, the coil is bad. Try both and see what coems up!
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