Need help-93' ls poor idle, no acceleration and running rich
#1
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Need help-93' ls poor idle, no acceleration and running rich
Hey I'm new to the club Lexus forums, my names Mitch. I recently purchased a mint 93' ls400 down here in London Ontario, Canada and having some troubles with it. I've done a ton of research on my problem and have come up with a wide array of problems it could be. I'm not made of money I believe in a proper diagnosis rather then just dumping money into something that has a simple fix. I'll try my best to name the symptoms. Prior to this, I have installed new plugs, caps and rotors to get rid of a misfire which I thought was my problem. Car ran AMAZING after I look a 5 min drive, when I got back it died on me.
Symptoms:
-running very rich, black smoke coming from the tail pipes.
-idles around 200rpms when I can get it to idle on its own, then it usually dies out shortly after
-has no acceleration, 0-60 in 10 seconds or so (much faster after I did the plugs etc.)
-won't rev over 2000rpms in drive, or 4000 in park
I work at a shop and I've had a few mechanics took at it, it's obvious it's a metering issue with the air/fuel ratio because it's running so rich it seems to be choking itself out because it doesn't have enough air. I have a couple friends with sc's and they all seem to think it might be the IACV, seems to be a common problem. I'd appreciate any advice you may have, I am new to the 1UZ so I am learning as I go. Thanks in advance.
Symptoms:
-running very rich, black smoke coming from the tail pipes.
-idles around 200rpms when I can get it to idle on its own, then it usually dies out shortly after
-has no acceleration, 0-60 in 10 seconds or so (much faster after I did the plugs etc.)
-won't rev over 2000rpms in drive, or 4000 in park
I work at a shop and I've had a few mechanics took at it, it's obvious it's a metering issue with the air/fuel ratio because it's running so rich it seems to be choking itself out because it doesn't have enough air. I have a couple friends with sc's and they all seem to think it might be the IACV, seems to be a common problem. I'd appreciate any advice you may have, I am new to the 1UZ so I am learning as I go. Thanks in advance.
#2
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Welcome to Club Lexus.
Several possibilities and further discussion about these are in the 2-LS FAQ (They overlap with the 1-LS so the discussions are listed there):
ECU : https://www.clublexus.com/forums/ls-...capacitor.html
ECT:https://www.clublexus.com/forums/ls-...read-this.html
Can be an IACV so worthwhile to go through because these are not uncommon maintenance areas.
Several possibilities and further discussion about these are in the 2-LS FAQ (They overlap with the 1-LS so the discussions are listed there):
ECU : https://www.clublexus.com/forums/ls-...capacitor.html
ECT:https://www.clublexus.com/forums/ls-...read-this.html
Can be an IACV so worthwhile to go through because these are not uncommon maintenance areas.
#5
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It simply means that your car is in the limp home mode. The main processor part is not working right and the sub-processor is working but it limits the rpm up to 2000rpm.
I'd quickly check the ECU measuring the ripple or simply replace QAS capacitors.
I'd quickly check the ECU measuring the ripple or simply replace QAS capacitors.
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A couple of guys at work suggested checking the fuel pressure, which I will do in the next couple days after I put the IACV back on (just took apart and cleaned w/ carb cleaner). I really appreciate your advice, it helps out huge.
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How would I go about measuring the ripple? I am thinking a lot of my problem has to do with the ECU but I don't want to rule out the same simple stuff as well. Limp mode makes sense, it is very sluggish.
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Here is one write up for it. I think its for gen 2, its a bit more difficult for some gen 1's.
https://www.clublexus.com/forums/ls-...-by-yamae.html
https://www.clublexus.com/forums/ls-...-by-yamae.html
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