91 LS400 HELP Sputtering Not Accelerating right
06-14-15, 05:49 PM
#16
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So guys yesterday I revved it to the revlimitter for about 3-5 seconds sounded bad *** lol. But funny thing was that I did that and it actually is running a little better. Even when it falls on its face its better. So tomorrow I am removing the cats and gutting them and putting them back on. I guess worse that could happen from this is it will sound better. Even if it dosnt fix my problem it will sound cooler and flow better. I did this on my SC and my old avalon. I will keep things posted just have alot of stuff going on right now on top of working 45 hours a week.
06-15-15, 08:23 PM
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To be honest I am not really sure. I barely drive it. I would say about a half a tank a week with 40mph stop n go for about 4-5 miles a day. When I drive it all 6 days for work. But I always let it warm up almost all the way to temp and sometimes for 20 min be for I drive it just because my trips are so short. I also drive my SC and some times me n the wife car pool in the Avalon. We work very close walking distance. But the old people that had it be for me had it for 5 years and only drove it in the summer. So I am pretty sure the car had probably 200k on it when they got it. Then putt putted around for the other 45k. Also it seems every thing in the engine bay area is extremely hot. The engine doesn't ever over heat and I have never seen them glowing red. But I have noticed a lot of heat in the engine bay along with an odd smell when I beat on it a bit.
06-18-15, 02:46 PM
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Well I hollowed out the front 2 cats. I found a crack in the manifold on the driver side right be for the o2 sensor. Naturally me beating the cats out made the crack bigger. So I put a weld on part of the crack in the only spot I could get to it. The car ran a little better but still has the same problem. Now with header tick lol. But I am changing the TPS when it comes in. I just don't get it, if I bounce the rev limiter it runs better for a little bit. I can get about half throttle out of it be for it starts to fall on its face. And when you floor it and let it rev it revs out very slow in till its about 1000rpm from the rev limiter. And then it revs as it should and bounces off the limiter as it should, fast and sounds nasty. WTF?!?!?!? I don't get it I am getting a little burnt out trying to figure this crap out with the LS. I am going to probably take a brake on it for a while and do some stuff with my SC. So as soon as I know any thing else I will let every one on here know.
06-20-15, 08:49 PM
#20
wireharness
I replaced the enigine wire harness that fooled the EFI, i was sure changing the TPS (with trac) would fix it but no.
I know changing the wireharness is a lot of work and only a new harness will give the right voltage and receive.
Using an old 20 yeras old wireharness is a danger you take.
Tip: keep it extreem warm im the garage so the harness will be soft and nothing will break.
succes
Lexter
I know changing the wireharness is a lot of work and only a new harness will give the right voltage and receive.
Using an old 20 yeras old wireharness is a danger you take.
Tip: keep it extreem warm im the garage so the harness will be soft and nothing will break.
succes
Lexter
06-20-15, 11:37 PM
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I would see if you can tee in to check voltage getting to the fuel pump when its running. I don't see you have checked the fuel pressure or when the pump has before or ever been changed. just that you have changed it to get full voltage all the time. Are u sure that is close to the 13.5V it should recieve on a running vehicle? I know lexus didn't make it easy to check fuel pressure on this vehicle. but you could disconnect the fuel filter inlet side hook a hose into a bucket and jump the fuel pump a rule of spec from my automotive training is at least 1 L / min should be flowing from the pump and I would assume maybe even higher for the lex. (especially if pump is at max output)
Also just because the coil can make spark out in the open doesn't mean its strong enough for combustion. There is a stronger resistance to spark under cylinder pressure where the air fuel mixture is compressed to thousands of psi versus the atmospheric pressure you tested it under. there should be a method to check coils on lexls? If not it might be worthwhile to get some cheap spares from the junkyard.
And also lots of compression is good. but 190 actually seems high. compression can be raised by having carbon deposits in cylinders. these can occur from frequent short trips, using mid or regular in cars that require premium or by not driving your car enough (Gasoline only lasts around 7 months before it begins to degrade) Have you tried running any cleaner through the system? this would work to break the carbon down if that is the issue and you would probably know if it was helping after the first tank of gas and 6$ cleaner. some cleaners are better than others. gumout regane high mileage has the most BPA which currently has the crown in cleaning abilities over older things like seafoam.
Also just because the coil can make spark out in the open doesn't mean its strong enough for combustion. There is a stronger resistance to spark under cylinder pressure where the air fuel mixture is compressed to thousands of psi versus the atmospheric pressure you tested it under. there should be a method to check coils on lexls? If not it might be worthwhile to get some cheap spares from the junkyard.
And also lots of compression is good. but 190 actually seems high. compression can be raised by having carbon deposits in cylinders. these can occur from frequent short trips, using mid or regular in cars that require premium or by not driving your car enough (Gasoline only lasts around 7 months before it begins to degrade) Have you tried running any cleaner through the system? this would work to break the carbon down if that is the issue and you would probably know if it was helping after the first tank of gas and 6$ cleaner. some cleaners are better than others. gumout regane high mileage has the most BPA which currently has the crown in cleaning abilities over older things like seafoam.
06-21-15, 12:27 AM
#22
https://www.clublexus.com/forums/ls4...problem-6.html
Since a friend maybe getting a 91 that the po says it sputters especially when hot and ac is on and on hiway.
I searched and found the above thread. Even with ECU swaps it ended up being the fuel pump.
Since a friend maybe getting a 91 that the po says it sputters especially when hot and ac is on and on hiway.
I searched and found the above thread. Even with ECU swaps it ended up being the fuel pump.
06-24-15, 05:31 PM
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I replaced the enigine wire harness that fooled the EFI, i was sure changing the TPS (with trac) would fix it but no.
I know changing the wireharness is a lot of work and only a new harness will give the right voltage and receive.
Using an old 20 yeras old wireharness is a danger you take.
Tip: keep it extreem warm im the garage so the harness will be soft and nothing will break.
succes
Lexter
I know changing the wireharness is a lot of work and only a new harness will give the right voltage and receive.
Using an old 20 yeras old wireharness is a danger you take.
Tip: keep it extreem warm im the garage so the harness will be soft and nothing will break.
succes
Lexter
06-24-15, 05:33 PM
#24
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I would see if you can tee in to check voltage getting to the fuel pump when its running. I don't see you have checked the fuel pressure or when the pump has before or ever been changed. just that you have changed it to get full voltage all the time. Are u sure that is close to the 13.5V it should recieve on a running vehicle? I know lexus didn't make it easy to check fuel pressure on this vehicle. but you could disconnect the fuel filter inlet side hook a hose into a bucket and jump the fuel pump a rule of spec from my automotive training is at least 1 L / min should be flowing from the pump and I would assume maybe even higher for the lex. (especially if pump is at max output)
Also just because the coil can make spark out in the open doesn't mean its strong enough for combustion. There is a stronger resistance to spark under cylinder pressure where the air fuel mixture is compressed to thousands of psi versus the atmospheric pressure you tested it under. there should be a method to check coils on lexls? If not it might be worthwhile to get some cheap spares from the junkyard.
And also lots of compression is good. but 190 actually seems high. compression can be raised by having carbon deposits in cylinders. these can occur from frequent short trips, using mid or regular in cars that require premium or by not driving your car enough (Gasoline only lasts around 7 months before it begins to degrade) Have you tried running any cleaner through the system? this would work to break the carbon down if that is the issue and you would probably know if it was helping after the first tank of gas and 6$ cleaner. some cleaners are better than others. gumout regane high mileage has the most BPA which currently has the crown in cleaning abilities over older things like seafoam.
Also just because the coil can make spark out in the open doesn't mean its strong enough for combustion. There is a stronger resistance to spark under cylinder pressure where the air fuel mixture is compressed to thousands of psi versus the atmospheric pressure you tested it under. there should be a method to check coils on lexls? If not it might be worthwhile to get some cheap spares from the junkyard.
And also lots of compression is good. but 190 actually seems high. compression can be raised by having carbon deposits in cylinders. these can occur from frequent short trips, using mid or regular in cars that require premium or by not driving your car enough (Gasoline only lasts around 7 months before it begins to degrade) Have you tried running any cleaner through the system? this would work to break the carbon down if that is the issue and you would probably know if it was helping after the first tank of gas and 6$ cleaner. some cleaners are better than others. gumout regane high mileage has the most BPA which currently has the crown in cleaning abilities over older things like seafoam.
Last edited by siccas; 06-24-15 at 05:39 PM.
06-24-15, 05:46 PM
#25
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https://www.clublexus.com/forums/ls4...problem-6.html
Since a friend maybe getting a 91 that the po says it sputters especially when hot and ac is on and on hiway.
I searched and found the above thread. Even with ECU swaps it ended up being the fuel pump.
Since a friend maybe getting a 91 that the po says it sputters especially when hot and ac is on and on hiway.
I searched and found the above thread. Even with ECU swaps it ended up being the fuel pump.
08-04-15, 02:48 PM
#26
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Hello Club Lexus
I found the problem. I swapped out one of the coil packs from my SC to the LS. IT Worked, runs as it should for being old and needing a tune up. Funny thing is I put the LS coil pack in to the SC. Runs just fine. !??!?!?!?!?!?! SOOOO...... Im buying a full tune up and timing belt for the LS. It runs so much better now. Iv heard of people running on just one coil pack. How that works is beyond me. May be i still have one bad one. But I am going to replace both with new ones and do a full tune up and timing belt kit. I want to thank everyone who has put in there input the clublexus ppl are awesome.
I will keep up on here but this will probably be my last post on this particular thread. Hope this will help other club lexus members find whats going on with there car.
I found the problem. I swapped out one of the coil packs from my SC to the LS. IT Worked, runs as it should for being old and needing a tune up. Funny thing is I put the LS coil pack in to the SC. Runs just fine. !??!?!?!?!?!?! SOOOO...... Im buying a full tune up and timing belt for the LS. It runs so much better now. Iv heard of people running on just one coil pack. How that works is beyond me. May be i still have one bad one. But I am going to replace both with new ones and do a full tune up and timing belt kit. I want to thank everyone who has put in there input the clublexus ppl are awesome.
I will keep up on here but this will probably be my last post on this particular thread. Hope this will help other club lexus members find whats going on with there car.
08-04-15, 10:41 PM
#27
Hello Club Lexus
I found the problem. I swapped out one of the coil packs from my SC to the LS. IT Worked, runs as it should for being old and needing a tune up. Funny thing is I put the LS coil pack in to the SC. Runs just fine. !??!?!?!?!?!?! SOOOO...... Im buying a full tune up and timing belt for the LS. It runs so much better now. Iv heard of people running on just one coil pack. How that works is beyond me. May be i still have one bad one. But I am going to replace both with new ones and do a full tune up and timing belt kit. I want to thank everyone who has put in there input the clublexus ppl are awesome.
I will keep up on here but this will probably be my last post on this particular thread. Hope this will help other club lexus members find whats going on with there car.
I found the problem. I swapped out one of the coil packs from my SC to the LS. IT Worked, runs as it should for being old and needing a tune up. Funny thing is I put the LS coil pack in to the SC. Runs just fine. !??!?!?!?!?!?! SOOOO...... Im buying a full tune up and timing belt for the LS. It runs so much better now. Iv heard of people running on just one coil pack. How that works is beyond me. May be i still have one bad one. But I am going to replace both with new ones and do a full tune up and timing belt kit. I want to thank everyone who has put in there input the clublexus ppl are awesome.
I will keep up on here but this will probably be my last post on this particular thread. Hope this will help other club lexus members find whats going on with there car.
11-26-15, 04:02 AM
#28
Sounds like you have an electrical problem if you have already found a rodent best in the valley of the engine block. I would hate to say it but it sounds like time to dissemble the wiring harness and find out where those pesky rodents were chewing.
Hello Club Lexus,
I have a 91 LS. The car is having a problem with accelerating and it sputtering while trying to accelerate. The more gas I give it the more it falls on its face. The throttle has one or two sweet spots sometimes and it will go nicely. One is up top barely on the gas and the other is about a 1/4 down and this isn't all the time. Some times it wont go at any throttle position. But if if it dose get the sweet spot and I slowly ease into the gas cant do more the a little less than half. It will do much better. Also some times as I'm just driving down the road about 40 it will randomly miss or sputter. The Tachometer is also off bad idle is 0-200 and red line shift point is about 4500rpm. The car doesn't stall at all and always starts right up. Has no CEL or stored codes.
I got the car from an older couple and it was from Texas. So its super clean and has 245k on it. They have had it for 5 years and parked it every winter. This winter after being parked they started it up and it was running bad. So I bought it. I also own 2 SC300's 5speed (93&94) and an Avalon (95). I also had a 96 Avalon and a 96 Tercel. So I'm not new to Toyota/Lexus. This LS tho has got me stumped and running out of ideas.
Here are a few things I have done to narrow down the problem that I cant seam to figure out. First thing I did was pull the ECU. Put a LED shop light behind the boards to check the caps. They all look good the ECU looks like new.
After that I changed the fuel rail dampener. Because the fuel rails were loud and noisy. Well the problem still there and the fuel rails were quieter but still loud. Then I bypassed the fuel pump ecu/resistor. This also did not do much but the car did work a little better with the same issue.
Then I did a compression test (190PSI on all 8) and did one distributor cap and all the wires. I cleaned the spark plugs at this time as well. The problem got no better.
So still scratching my head I decided to change all the fuel injectors and fuel filter. Problem is still there.
At this point I have began to unplug things. When I unplug the TPS the car will idle up about 100-200 rpm and smooth out but still drives and sputters the same with acceleration. The shifts become bad from the ecu not knowing where the throttle is but the car dose seam to be easier to drive with the sweet spots. Funny thing is even with the TPS unplugged the car still doesn't throw a check engine light. So I tried unplugging the MAF/AFM and coil packs while it was running to see if it would throw a code. Well it threw all 3 codes for the things I unplugged except the TPS. I am still driving it around with the TPS unplugged because it is a little bit easier to drive but the problem is still there and has no idea what the correct shift points are.
Another thing I am thinking of trying is the knock sensors. There was a mouse nest in the vally of the block under the intake manifold. If you know 1UZ's this is a ***** to get to these to even try and test. Im thinking they may have gotten chewed up by a mouse. But once again no codes or stored codes.
I am running out of options and ideas. I think I am going to order a TPS just for ****s and giggles to see if that works. Then maybe move on to the knock sensors and fuel pump. I need to do a timing belt but i don't want to dump bunch of money in the engine b/c i could buy an engine for like 800$.
So if any of you have had a problem like this and fixed it I would love to know. I have spent hours on top of hours reading threads and looking up this problem to find tons of different people talking about problems similar to mine. But nothing has seem to get me any where. Club Lex Please HELP
I have a 91 LS. The car is having a problem with accelerating and it sputtering while trying to accelerate. The more gas I give it the more it falls on its face. The throttle has one or two sweet spots sometimes and it will go nicely. One is up top barely on the gas and the other is about a 1/4 down and this isn't all the time. Some times it wont go at any throttle position. But if if it dose get the sweet spot and I slowly ease into the gas cant do more the a little less than half. It will do much better. Also some times as I'm just driving down the road about 40 it will randomly miss or sputter. The Tachometer is also off bad idle is 0-200 and red line shift point is about 4500rpm. The car doesn't stall at all and always starts right up. Has no CEL or stored codes.
I got the car from an older couple and it was from Texas. So its super clean and has 245k on it. They have had it for 5 years and parked it every winter. This winter after being parked they started it up and it was running bad. So I bought it. I also own 2 SC300's 5speed (93&94) and an Avalon (95). I also had a 96 Avalon and a 96 Tercel. So I'm not new to Toyota/Lexus. This LS tho has got me stumped and running out of ideas.
Here are a few things I have done to narrow down the problem that I cant seam to figure out. First thing I did was pull the ECU. Put a LED shop light behind the boards to check the caps. They all look good the ECU looks like new.
After that I changed the fuel rail dampener. Because the fuel rails were loud and noisy. Well the problem still there and the fuel rails were quieter but still loud. Then I bypassed the fuel pump ecu/resistor. This also did not do much but the car did work a little better with the same issue.
Then I did a compression test (190PSI on all 8) and did one distributor cap and all the wires. I cleaned the spark plugs at this time as well. The problem got no better.
So still scratching my head I decided to change all the fuel injectors and fuel filter. Problem is still there.
At this point I have began to unplug things. When I unplug the TPS the car will idle up about 100-200 rpm and smooth out but still drives and sputters the same with acceleration. The shifts become bad from the ecu not knowing where the throttle is but the car dose seam to be easier to drive with the sweet spots. Funny thing is even with the TPS unplugged the car still doesn't throw a check engine light. So I tried unplugging the MAF/AFM and coil packs while it was running to see if it would throw a code. Well it threw all 3 codes for the things I unplugged except the TPS. I am still driving it around with the TPS unplugged because it is a little bit easier to drive but the problem is still there and has no idea what the correct shift points are.
Another thing I am thinking of trying is the knock sensors. There was a mouse nest in the vally of the block under the intake manifold. If you know 1UZ's this is a ***** to get to these to even try and test. Im thinking they may have gotten chewed up by a mouse. But once again no codes or stored codes.
I am running out of options and ideas. I think I am going to order a TPS just for ****s and giggles to see if that works. Then maybe move on to the knock sensors and fuel pump. I need to do a timing belt but i don't want to dump bunch of money in the engine b/c i could buy an engine for like 800$.
So if any of you have had a problem like this and fixed it I would love to know. I have spent hours on top of hours reading threads and looking up this problem to find tons of different people talking about problems similar to mine. But nothing has seem to get me any where. Club Lex Please HELP
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