No Accerlation

[Delo3428]

I have 1992 LS 400. The issues I'm having are

- I'm getting to accerlation

- have a strong gas smell

I had catylitic converts check out, they are not stopped . I have no check engine light on and the car runs smooth. Can some assist me with this issue...

[KeyKeeper]

sounds like its in limp mode. no codes at all?

[Delo3428]

No, There are no codes, no lights at all

[KeyKeeper]

have you physically had the car scanned for codes? Lights dont always tell the story.

[SRK]

Sounds like one of the ignition coils has failed. Very common, and no codes are produced.

Check the primary winding resistance of each of the two coils. I believe they are supposed to be around 5-7 ohms, but more than likely one of them will have a resistance substantially more than the other.

The other option is to hook a timing light to the secondary wire coming out of the each coil and see which one is not producing spark voltage. Easier to check the primary though.

Are your converters overheating and turning red hot? That's another sign.

Stop driving the car until it is repaired too.

[KeyKeeper]

Seems with no codes present, the secondary voltage side of the coil pack would have failed. A timing light on the wires would be a good test for this. He did say the car runs smooth though so its a bit odd. Seems a missing cylinder would cause some vibration issues under any type of load.

[Delo3428]

Converters checked out good, they are not over heating.

[SRK]

It would take a little while for the converters to overheat, and the colour is best seen at night. They'll also smoke a bit as road deposits burn off.

The coils on your car are the normal external armature type. Each one fires four cylinders in alternate sequence with the other coil, so the engine will appear to idle quite well, but have no power. The cylinders that do not fire exhaust unburned fuel into both cats, which is why they'll overheat.

The next thing to check would be fuel pressure and you'll need a gauge that can hook up to the schrader valve on the fuel rail. Pumps rarely fail. Coils fail though.

When I sold my 92 LS I gave the manuals to the next owner - a buddy. He had a coil fail last year, and the primary resistance proved which coil quite quickly. Test both, and compare - they should be exactly the same. If not, the one that is outside the normal range is the culprit.

[landar]

It is really pretty simple to test the coils. Pull the main hi-voltage line on each coil, one at a time, with the engine running (use isolated pliers or clamp so you do not get zapped...or pull the ignitor connector that drives the coil) If, after pulling one of the wires or ignitor, there is no change in engine operation, then you have found a bad coil (or rotor, ignitor, cap). If the engine operation changes, the coil, and associated ignition components, is good.

Since you are smelling raw gas, I would guess that you have an ignition issue.

[fsuguy]

Check the following:

1. Ignition coil(s)

2. TPS

Specs for both are in the shop manuals, or look on this site for info: http://www.ls400.ru/lexus-89-2000/RepairManual1992.html

Also, if you have a schrader valve on your fuel rail, I would like to know exactly where it is, since I have a '92 and do not have one of those!!

Hope this helps

[curiousB]

Common problem on these cars. Check the coils. That is 80% likely the problem. As Landar and SRK suggest, it is not too hard to self test. The car will continue to run rough when you disconnect the bad coil (since its not doing any good already) but when you disconnect the good coil the engine will die. Put a new coil in and you're back on the road, no gas smell, no red hot catalytic converters, and all the power you need to secure a handful of speeding tickets.

[Yamae]

I suspect that the ECU has leaking capacitors.

[fsuguy]

Hi Yamae,

I followed your other thread about the ECU capacitor repair - do you have an updated list of manufacturers and capacitors that I could use to replace mine with? ('92 w/o traction)

Thanks

[Yamae]

Sorry for the late reply. Check below.

http://www.clublexus.com/forums/ls400/656360-all-my-crazy-lexus-issues-solved-ecu-leaking-capacitor.html

[fsuguy]

Yamae,

thank you for the reply - that is good information.