Power Loss/hesitation

[JTF NJ]

Just bought a 92 ls400 with 68,000 orig miles. Was 1 owner garaged kept and Ray Catena serviced(local lexus dealer) About 800 miles ago while my foot was stepping on the gas it was loosing power/Hesitating. It still ran but you had to really step down on the pedal and it went back to normal. At this time it did not stall and still ran great but it hesitated. Once it got power there was no problem.

Until today.4 weeks later and 400 miles

I ran the car in the driveway for a few minutes and reved it a bit..Did not dog it. Drove less than 1 mile and started to lose power/hesitate again.

I stoped and turned it off, ran my erand and it started right up. It was still hesitating but I was kinda pumping the pedal on the way home. Then I got closer to home and almost floored it and it kicked right back to normal.

Drove it around and it seems ok.

Any one wth ideas..a fluke..gas filter..pump...none of the above

I hecked and it is upto date on serv.

Thanks JTF NJ

Also even when I stop pressing the gas while hesitation it runs smooth?

Thanks for all your help. I had the car Motor vac fuel system service done by my Mech. He said since the car has only been run about 1000 mls a yr for the past 4 or so years carbon may have built up.

So far so good but I do not use it that much myself. Also had the alt go. I was nervous of elec. problems since my dash lit up little by little(icons) the radio stopped working then the cruise..then dead.

Once again thanks every one JTF

[curiousB]

I would check to see that one of the distributor/coils hasn't gone bad. This will revert engine to 4 cylinder with serious lack of power. Coils can fail intermittently so the problem can come and go. Search the forum. This is a very common problme for these cars.

[JTF NJ]

I would check to see that one of the distributor/coils hasn't gone bad. This will revert engine to 4 cylinder with serious lack of power. Coils can fail intermittently so the problem can come and go. Search the forum. This is a very common problme for these cars.

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Will this show up on a diagnostic?

Thanks JTF

[curiousB]

Any competent mechanic should be able to determine this in about 5 minutes.

If you're ambitious you can even try yourself.

With car running pull a plug wire from one of the distributor caps. If that distributor is working then you should see the engine bog down a little as it will be going from 4 working cylinders to three. Kill the engine plug wire back in. Now try the same thing on the other side. If one distributor/coil is dead then pulling wires on it should make no difference yet pulling of a good one will make a noticeable difference. This will at least let you know if you have a complete failure in half your cylinders. Probably a new coil on that side would fix it.

[93ls400walt]

If the engine runs smoothly at idle and when you are not trying to accelerate more than just slowly. I doubt that it is the coil ( the driver side coil seems to go first due to its low position and engine heat so I have read and experienced)

I have a 93ls that had simular to what you described and there seems to be a few 90-94 post with simular issues. Try to read your cel codes and post any you get. It may be your TPS code 41. But my early bet is that it is you ECM. Don't pass out as a new one is around 1500+. There are some repair shops for ECM's and used ones for 100-300. Very easy to change out.