1991 Ls400 Won't Start After Replacing The Starter

[jqzhang]

I have a 1991 Lexus LS400 that won't start after replacing the starter.

Say more about the car: the starter stopped working in Jan. 2009 because of the contact points are worn. BTW, it has 142,000 miles on it.

The car was parked at a open space and it was too cold to work on changing a starter for a LS400. I guess you know how much pain to take to get the job done.

Finally the starter was fixed (only changed the contact points) and re-installed.

As I turn the ignition on, the starter will spin because you can see the cooling fan is turning and so is the timing belt (moving). But the problem is 1) it won't start; 2) I can hear the starter spinning but not cranking.

I checked the plugs. Most of them are dirty so I cleaned them. They were wet too maybe because of the fuel dumped in the cylinders as I tried to start the car. So I removed the injection fuse. Still, not luck.

I'm going to check the diagnosis code tomorrow see if any error code comes up.

Any suggestions and hints are welcome. I am stuck here.

Thanks in advance.

[93ls400walt]

I would check all of the connections that were disconnected or could of been damaged during the rebuild. Also after setting for so long I would remove as much of the old gas as possible and add fresh gas and maybe a can of dry gas to address ant water in the gas.

Is the engine firing at all? If the engine is not cranking how is the fan turning?

[jqzhang]

I would check all of the connections that were disconnected or could of been damaged during the rebuild. Also after setting for so long I would remove as much of the old gas as possible and add fresh gas and maybe a can of dry gas to address ant water in the gas.

Is the engine firing at all? If the engine is not cranking how is the fan turning?

Thanks for replying.

After a few times of trying, the engine finally started. It ran pretty well, at least as well as before replacing the starter, after adding 2 bottles of injector cleaner and one dry gas.

However, after driving a few miles, the car started hesitating when speeding up. It will start fine but still hesitate as accelerate, not stalling. As it idles, it's kind of rough: I kept the door open putting my hand on top of the door, I can feel slightly shaking.

One more symptom, before the starter change, it had error code of 28, the main oxygen sensor at the right bank. After the changing the starter, the check engine light is gone. I don't think the sensor back to normal without fixing. I suspect the ECU got confused which leads to the rough idling. What do you think?

Thanks again.

[93ls400walt]

the rough idle could still be the old gas. I would try a can of seafoam and fill up with some premium gas. did the cel code return? It was cleared when, I assume, if you had the battery disconnected during the starter replacement.

[Lucky13]

The fuel pump or the wiring for the pump may not be runing correctly either.

[curiousB]

Not sure the wiring is a likely candidate. Suggest you invest in a fuel pressure gauage for $20 and you can take measurements to get a quantitative reading. Assuming it is a fuel problem in addition to just bad gas it could be fuel pump but also could be plugged fuel filter or clogged injectors.

[jqzhang]

Not sure the wiring is a likely candidate. Suggest you invest in a fuel pressure gauage for $20 and you can take measurements to get a quantitative reading. Assuming it is a fuel problem in addition to just bad gas it could be fuel pump but also could be plugged fuel filter or clogged injectors.

Thank you all for replying.

No, the error code has not come back yet.

Looks like you folks argue it's more like a EFI problem. I'm not sure if I agree but I don't have evidence it's not. I suspect something wrong with ECU, maybe caused by the faulty oxy sensor.

I have no problem starting the engine at all, either use the old battery or the newly bought one. But as the engine's running, you can feel it's weak.

At the first time it started after the replacement, the engine ran very well. It speeded up as good as before. But it did not last long.

Another possibility is the catalyst converters. Because as I tried to smell the exhaust from the tail-pipe, it did not smell the same as before but it's not like rotton eggs either.

OK, I'll take you guys' advice and replace the rest gas and fill the tank with new, at the weekend.

Thank you all again for involvement.

[curiousB]

Well obvious questions. Did you use new gaskets on all manifold sections removed? An intake manifold leak would result in poor idling and rough engine (more at lower speeds).

If the O2 is faulty you should see a code in the ECU error log. Need an OBD2 reader to check. Don't convict the messenger (ECU) for the problem just yet. It is reporting the bad news, but not necessarily the cause of the bad news. I don't see how changing starter would create an ECU failure. I'd keep digging before putting much stock in that theory.

Things I’d check:

1) Vacuum leak, leaky gasket, miss routed hose, missing hose..

2) Ignition wiring (simple error of crossed wire or two)

3) Ignition something wrong with coil, rotor or cap wiring?

4) Check ECU error logs

5) Measure fuel pressure, check pressure at higher revs to see it can deliver fuel pressure AND volume under engine load.

6) IACV and Throttle body cleaning

[jqzhang]

Well obvious questions. Did you use new gaskets on all manifold sections removed? An intake manifold leak would result in poor idling and rough engine (more at lower speeds).

If the O2 is faulty you should see a code in the ECU error log. Need an OBD2 reader to check. Don't convict the messenger (ECU) for the problem just yet. It is reporting the bad news, but not necessarily the cause of the bad news. I don't see how changing starter would create an ECU failure. I'd keep digging before putting much stock in that theory.

Things I’d check:

1) Vacuum leak, leaky gasket, miss routed hose, missing hose..

2) Ignition wiring (simple error of crossed wire or two)

3) Ignition something wrong with coil, rotor or cap wiring?

4) Check ECU error logs

5) Measure fuel pressure, check pressure at higher revs to see it can deliver fuel pressure AND volume under engine load.

6) IACV and Throttle body cleaning

I did change Intake Chamber and Manifold gaskets ($40 for both bought from Pepboy) and re-tightened the bolts and nuts.

About 1) yes, I did not hear any hiss but I'll use soap water to check it out;

2) I did not take out the ignition wires since I did not have to. I only removed the intakes, to change the starter;

3) yes, I'll double check even they were OK before changing the starter;

4) How? It's a 1991 LS400, and OBDII cannot be used... Right, you remind me. I have a OTC 4000 and it can do most of the cars older than 1994;

5) make sense; let me dump all the old gas first. Yesterday, I added one more bottle of Gas Treatment and it did not help;

6) I've done that.

BTW, as I took apart of the intakes, I broke one of the filters of EGR VSV. I think it's just a filter and it won't cost this kind of engine problems.

Thanks again.

[curiousB]

Well .......

About 1) yes, I did not hear any hiss but I'll use soap water to check it out;

This is intake manifold, therefore negative pressure, so soapy water not a good idea as a leaky vacuum won't make bubbles, instead it will draw the soapy liquid into the cylinder. Probably nothing good can come from that.

I've heard, but not tried, that a propane torch turned on low without lighting the flame is a way to search for intake vacuum leaks. If you have a leak and pass propane by the leak, the motor will lightly rev up for a moment before IACV throttles it back down. Obviously be careful with propane gas and do it outside (not in garage) but it seems a pretty simple test to "sniff" out a vacuum leak.

[maxed_out]

Hi, I hope you fix it...my 91 did the same thing. Drove me nuts. Mine turned out to be a corroded fuel line that was allowing air to pull in. Didnt show up in the FP test. While I was there I changed the fuel filter. Let me tell you the job to replace the fuel line from the tank to the front is a real stinker. I surmise that the salt used on the roads really does a number on the fuel line.

By the way for some weird reason it didnt leak.

Good luck. Max

[jqzhang]

Hi, I hope you fix it...my 91 did the same thing. Drove me nuts. Mine turned out to be a corroded fuel line that was allowing air to pull in. Didnt show up in the FP test. While I was there I changed the fuel filter. Let me tell you the job to replace the fuel line from the tank to the front is a real stinker. I surmise that the salt used on the roads really does a number on the fuel line.

By the way for some weird reason it didnt leak.

Good luck. Max

Hi guys,

Frankly, I'm almost on the verge of giving up. As a last resort, I might probably drive the car to the dealer and ask them to check it out using their computers.

Let me tell what I did today.

1) I used a propane torch (as CuriousB suggested) to move around the areas of intake manifold, vaccum hoses, with the engine running. But the engine idle did not change a thing;

2) I filled the tank with 93 octane gas, with 1.5 bottles of Gas Treatment and dry gas, more than enough to dilute the water and other foreign stuff in the tank but it did not improve anything;

3) I tried OTC 4000 but the hand-held computer couldn't read the ECUs of the car;

4) what's even worse, I can tell there must be some coolant leaking somewhere because I saw some coolant in the front part of the engine valley. I checked the rear by-pass bolts but they were tight enough. As the engine is hot , there's some smoke coming out of the rear of the engine but it didn't smell coolant;

Let me tell you more about the symptoms: as the engine idling, it's not quite precise to say 'rough' since it's quite stable but weak; I put my hand at the tailpipe and I can feel a quite stable and strong 'puff,puff,puff'; but normally I should feel the puff but not as strong as it is now.

I'll keep checking, especially the fuel lines.

Thanks again.

[jqzhang]

Hi, I hope you fix it...my 91 did the same thing. Drove me nuts. Mine turned out to be a corroded fuel line that was allowing air to pull in. Didnt show up in the FP test. While I was there I changed the fuel filter. Let me tell you the job to replace the fuel line from the tank to the front is a real stinker. I surmise that the salt used on the roads really does a number on the fuel line.

By the way for some weird reason it didnt leak.

Good luck. Max

Hi folks,

I finally fixed the problem. Just take a wild guess about what really happened. I couldn't believe it until I found that out: one of the ignition coil went bad.

I cleaned up all the fuel system like I said before but nothing improved. The next step was to check the electrical system. I was lazy so I started with the easy one: checking the sparks plugs. Before I took them out, I disconnected one of the ignition cable to see how the engine behavior changed with the engine running. As I tried the second one, the engine ran the same way with or without the ignition cable and it meant that cylinder not working I checked the 4 cylinders on the driver side and 2 of them not working, which means 2 of them on the other side also not working. The car has only 4 cylinders working and the other 4 are not. That's exactly why it felt the engine was so weak but running relatively stable. That's why I suspect the fuel might be OK because the engine wouldn't run stable if the fuel had a problem.

I bought a coil at Pepboy at $40 and replaced the coil next day. Now the engine runs even better than before the replacement of the starter.

But it's not over yet.

The car failed emission check at a inspection station. Both HC and CO are too high, especially CO. The funny thing is that CheckEngine light is not always there. I used to have a trouble code 28; I checked again the other day, it turned out a 25: air and fuel mixture too lean. I believe it might partially cause the failure of inspection. I'll keep checking.

One more question for you guys.

The situation has nothing to do with the replacement of the starter. As I am doing 45 to 50 and trying to speed up, the car feels instant jerky. It feels like the tranny tries to lock up but fails. I don't think it's an engine problem. Does anyone have this kind of experience? Somehow, my 95 LS has slightly the similar feelings but not as obvious as the 91.

Thanks again to all.

[jqzhang]

Hi, I hope you fix it...my 91 did the same thing. Drove me nuts. Mine turned out to be a corroded fuel line that was allowing air to pull in. Didnt show up in the FP test. While I was there I changed the fuel filter. Let me tell you the job to replace the fuel line from the tank to the front is a real stinker. I surmise that the salt used on the roads really does a number on the fuel line.

By the way for some weird reason it didnt leak.

Good luck. Max

Hi folks,

I finally fixed the problem. Just take a wild guess about what really happened. I couldn't believe it until I found that out: one of the ignition coil went bad.

I cleaned up all the fuel system like I said before but nothing improved. The next step was to check the electrical system. I was lazy so I started with the easy one: checking the sparks plugs. Before I took them out, I disconnected one of the ignition cable to see how the engine behavior changed with the engine running. As I tried the second one, the engine ran the same way with or without the ignition cable and it meant that cylinder not working I checked the 4 cylinders on the driver side and 2 of them not working, which means 2 of them on the other side also not working. The car has only 4 cylinders working and the other 4 are not. That's exactly why it felt the engine was so weak but running relatively stable. That's why I suspect the fuel might be OK because the engine wouldn't run stable if the fuel had a problem.

I bought a coil at Pepboy at $40 and replaced the coil next day. Now the engine runs even better than before the replacement of the starter.

But it's not over yet.

The car failed emission check at a inspection station. Both HC and CO are too high, especially CO. The funny thing is that CheckEngine light is not always there. I used to have a trouble code 28; I checked again the other day, it turned out a 25: air and fuel mixture too lean. I believe it might partially cause the failure of inspection. I'll keep checking.

One more question for you guys.

The situation has nothing to do with the replacement of the starter. As I am doing 45 to 50 and trying to speed up, the car feels instant jerky. It feels like the tranny tries to lock up but fails. I don't think it's an engine problem. Does anyone have this kind of experience? Somehow, my 95 LS has slightly the similar feelings but not as obvious as the 91.

Thanks again to all.