1992 LS400 has got me stumped !
#1
Driver School Candidate
Thread Starter
Join Date: Sep 2012
Location: AL
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
1992 LS400 has got me stumped !
My problem started out with white smoke coming out of the tail pipes . I chased the problem down to a bad pressure switch on the power steering pump . The vacum lines to the pump was sucking power steering fluid back into the intake manifold . I took one of the vacum lines off, and it stop smoking. I was on my way to work, and it started smoking bad and loosing power . I also noticed a light on the left side of the dash that came on about the same time, it's yellow and looks like a bird cage with a ball on top . The car finally wouldn't go over 20mph, so I pulled over and checked all of my fluids; all where ok . So I called roadside and had the car towed home . I cranked it the next day, and it drove fine for about 50 miles or so, and then started to loose power again . I once again towed it home, and there it has sat . The car does crank and idle fine, but when you give it gas, it dies . I've done a complete tune up (plug's,wire's, cap's and rotor's) . A compression reading shows 200 to 220 on all cylinder's except the second cylinder from the front on the driver's side, and that one only read's 160 . When the car is idling and cuts off after you give it gas, it will not start back unless you take the second or third spark plug out on the driver's side . I found this out after checking the plugs one at a time to see if any were fouling out . Can anybody out there help me with this ?
#2
I have a 92. I can say the yellow light you mentioned on dash is low coolant light. Mine started doing that but level was good. Disconnected the connect to stop it for awhile but later just bought a new sensor. No more issue. your other problem may be the trunk harness wire issue so many have experienced. Do a search for trunk harness and see if other people issue matches yours.
#3
Driver School Candidate
Thread Starter
Join Date: Sep 2012
Location: AL
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
Now I understand what the light is, but can anyone offer any suggestions as to why my car is running like it is ? My mind tells me that the head gasket is blown, but I've heard so many say that the LS is tough and that a blown head is highly unlikely .
#7
Driver School Candidate
Thread Starter
Join Date: Sep 2012
Location: AL
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
No water in the oil . Have taken the cam/valve covers off to make sure that followers were working correctly, and that I didn't have any stuck or bent valves . All component's work correctly . Will do a leak down test in the morning and post result's here . Thankx for the help and suggestion's .
Trending Topics
#8
Instructor
If you engine runs OK, than starts to run funny, you likely have a intermittent issue. If it were to be a bent valve or something, you'd notice it everything time the valve was supposed to operate, not here and there. Your compression tests are fine, don't waste your time doing a cylinder leakage test, because like a bent valve you'd notice it consistently.
You need to test fuel pressure. If your at the spec. fuel pressure, and you hit the gas, it should maintain roughly the same pressure in the rail. If the pressure drops, you would know why the engine bogs down as the injectors are being starved of fuel. A lot of the times, the pump will keep you right around the base number for pressure, but as flow increases, and pressure drops, the pump can't keep up causing a major drop in the fuel rail, again starving the injectors causing you to miss/stall. If you are lost on any of what I told you, you should bring it to a technician to have them dive into it. To me, it sounds like a fuel or spark issue, most likely fuel.
You need to test fuel pressure. If your at the spec. fuel pressure, and you hit the gas, it should maintain roughly the same pressure in the rail. If the pressure drops, you would know why the engine bogs down as the injectors are being starved of fuel. A lot of the times, the pump will keep you right around the base number for pressure, but as flow increases, and pressure drops, the pump can't keep up causing a major drop in the fuel rail, again starving the injectors causing you to miss/stall. If you are lost on any of what I told you, you should bring it to a technician to have them dive into it. To me, it sounds like a fuel or spark issue, most likely fuel.
#9
Driver School Candidate
Thread Starter
Join Date: Sep 2012
Location: AL
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
I want to thank everybody for thier feedback, help and support ......
In my last post, I said that I would do a leak down test, have done so and found out that all cylinders are holding thier own except for number 8 (passenger rear) . Also found out that my timing was off .
Have tore the engine down, and am in the process of putting it back together . Just finished the timing belt tonight, and will do the rest tomorrow . Will post the result's in this forum .
I will definitey check to see if I have a fuel problem, thanks for the advice; my mind told me to check that, but I like to get as much feedback as I can about a problem before making a decision .
I did have a problem once before with the car not firing on the passenger side, as well as a fuel problem; but I repaced the coil on that side, and replaced the fuel pump/filter & sock, but will definitely recheck everything since the car sat up for a few years before I got it .
In my last post, I said that I would do a leak down test, have done so and found out that all cylinders are holding thier own except for number 8 (passenger rear) . Also found out that my timing was off .
Have tore the engine down, and am in the process of putting it back together . Just finished the timing belt tonight, and will do the rest tomorrow . Will post the result's in this forum .
I will definitey check to see if I have a fuel problem, thanks for the advice; my mind told me to check that, but I like to get as much feedback as I can about a problem before making a decision .
I did have a problem once before with the car not firing on the passenger side, as well as a fuel problem; but I repaced the coil on that side, and replaced the fuel pump/filter & sock, but will definitely recheck everything since the car sat up for a few years before I got it .
Last edited by BangEmBoy; 09-17-12 at 09:01 PM.
#10
Driver School Candidate
Thread Starter
Join Date: Sep 2012
Location: AL
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
I have install a new timing belt, distributor cap& rotors, wires and plugs . My car still has the same problem . After checking my fuel components and finding that all were good and working properly, I moved on to the ignition system for further troubleshooting, and found out that my injectors are not firing . Upon hooking up my digital multi-meter, I found out that I am getting fire (12.78 volts) to the injector's, but no ground signal . Thinking that it might be the ECU, I replaced it, and am still getting the same problem; no ground signal . I then kicked the ECU into diagnostic mode and got codes 24 & 31 .....
Has anyone else ever ran into this before ? If you have, what steps did you take to revolve this issue . Thanks
Has anyone else ever ran into this before ? If you have, what steps did you take to revolve this issue . Thanks
#11
Lexus Test Driver
iTrader: (1)
I have install a new timing belt, distributor cap& rotors, wires and plugs . My car still has the same problem . After checking my fuel components and finding that all were good and working properly, I moved on to the ignition system for further troubleshooting, and found out that my injectors are not firing . Upon hooking up my digital multi-meter, I found out that I am getting fire (12.78 volts) to the injector's, but no ground signal . Thinking that it might be the ECU, I replaced it, and am still getting the same problem; no ground signal . I then kicked the ECU into diagnostic mode and got codes 24 & 31 .....
Has anyone else ever ran into this before ? If you have, what steps did you take to revolve this issue . Thanks
Has anyone else ever ran into this before ? If you have, what steps did you take to revolve this issue . Thanks
http://us.lexusownersclub.com/forums...howtopic=37893
#13
Driver School Candidate
Thread Starter
Join Date: Sep 2012
Location: AL
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for your reply, but did I fail to mention in my post that I bought a computer when I first bought the car because it didnt have one ? I also bought a second one that came out of a running LS, and I still have the same symptoms . But I will take your suggestion under advisement and take the one out of my other running LS that I use for a daily driver and try it . Once again, thank you for your suggestion .
#14
Driver School Candidate
Thread Starter
Join Date: Sep 2012
Location: AL
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
I have switched the ECU from my running 90LS to my Demon Spawn 92LS with no difference in symptoms . And to rule out the ECU being bad, I put the ECU form the 92 into the90 and it ran like a champ . I am at a lost with this vehicle, can anyone out there offer me anymore suggestions ? Thanks