sayow

Just acquired a 93 LS for practically nothing and one of the first thing I noticed is a SEVERE lack of power. I have read through various threads and most detail other symptoms such as backfires and sputtering but this LS has none of that.

The car starts just fine and upon listening to idle, you would not think anything is wrong. You start to drive and you can hear what might be an exhaust or vacuum leak but what really hits you is the severe lack of power.

I have read others talking about their lack of power resulting in 11 or 12 second 0-60 times... this car despite idling great would be hard pressed to do 0-60 in 30 seconds flat and keeping it at highway speeds requires keeping the foot in it hard and/or turning OD off.

I think it is important to note that when driving/accelerating and experiencing the issue (which is NOT intermittent, its 100 percent of the time) that the car makes not sputtering or stalling noises, no backfires and nothing abnormal other than what sounds like a possible exhaust or vacuum leak during early acceleration.

Where to start? No CEL.

Thank you in advance.

sayow

Just read the entirety of the ECU thread and am encouraged to think that perhaps half my cars issues COULD be resolved with a new ECU (or new caps but I have no desire to solder).

So if I read correctly, the ECU could be the cause of the following:

1. Massive power loss
2. RPM gauge inoperable and consistently sitting below 1k
3. Fuel gauge inoperable
4. VSC inoperable
5. World peace*

So other than costing a little more, what would be the problem with just buying a refurb ECU for my 93? I see them consistently for under $100. Is the concern that a refurb still has old 1993 capacitors that can still go out?

I think some enterprising soul should get into the business of buying ECUs, adding new capacitors and selling to forum members... me first


* not really

LScowboyLS

yes, this does sound like a classic case of bad ECU capacitors, please either run Yamae's ripple test, or else pull the ECU and photograph the inside of it clearly and Yamae and I will check it out!

I have never seen a reburb or rebuilt ECU that used the correct capacitors! - The correct capacitors are a pretty rare type. We have had many recipients of these post what they received in the ECU thread and the quality of the caps is awful and not even the right type - maybe the rebulders are cheap or just ignorant or just don't care, I am not sure!

timmy0tool

iTrader: (7)

most likely the rebuilders are not as knowledgeable on the proper type of caps as what is identified in the thread. they probably don't even know about this forum.

get the capacitors replaced, and most of your issues may go away!

sayow

UPDATE - would love some feedback from the experts!

Just installed a freshly repaired ECU and while the shifting is now nice and smooth, the car still has a SEVERE lack of power. I checked all vacuum lines and found one line missing (from intake). I replaced that and the idle has improved to sounding perfectly normal.

However once I step on the gas, the car feels like its running on 4 cylinders and there is a "fluttering" sounds that is reminiscent of an exhaust leak.

I would like to get a prioritized list of items to check first in an effort to not turn this "backup LS" into a money pit. I plan to clean the MAF and intake first, then proceed to plugs and wires but would like some of the pros here on the forum to give me some other places to look.

Ignition rotors?
TPS?
PCV?
Probably a host of other sensors I should look at so any guidance is much appreciated.

Thanks!

johnnyg66

Just a thought a bad ignition coil.

sayow

Excellent thought. Thank you.

Help me build my list which so far includes:

New PCV
New Ignition Coils
New Plugs and Wires

johnnyg66

Caps and rotors.

LScowboyLS

agreed on the caps and rotors, plugs and wires, would add the Engine Coolant Temp Sensor to that list. (I would go genuine Toyota on the caps, rotors and temp sensor - plugs and wires just need to be Denso or NGK)

also try driving the car without the MAF (AFM) electrically connected, see if that makes a difference

also, inspect timing belt alignment, you could be a tooth off

LScowboyLS

quick test of igniters, coils, and associated wiring is at 5:53 in this video

Kingsoup

I had a similar problem, my crappy intake had lost foam into the MAF, check that MAF and make sure shes clean.

LScowboyLS

be sure to NOT use any solvent on a pre-95 MAF (AFM) - and if yours ends up being bad, some previous owner cleaning it is very likely what killed it in the first place!

chamois or low PSI dry compressed air are the only suitable cleaners, but if someone used a solvent on it before, it's toast!

Finn

May I be so bold to suggest the basic checks/changes first:
- fresh fuel
- fuel filter
- air filter
- plugs
- error codes
- air leaks
etc.

If these do not correct the situation then you will at least know that the basics are in order.

sayow

All good suggestions.

The car has fresh fuel and the filter was the first thing changed. I have not changed the air filter but would be VERY surprised if it could cause this much of a problem. As mentioned, I did check for air leaks and found the previous owner had just used electrical tape to cap the missing line from the front center of the intake to the intake hose. I replaced that and it help smooth out idle but not help during throttle under load.

Plugs will be ordered with wires and a set of coils which sound like a good place to start. Was hoping the ECU would magically fix it, no such luck

LScowboyLS

I wouldn't start replacing extremely well-made Lexus parts with cheap auto part store parts, or you soon won't have a Lexus, you will have a Chinese beater.

for example coils, if you have a bad coil, fine, put a genuine Toyota OEM coil on it, but otherwise, that is a lot of money to spend on the Toyota part, and I wouldn't care to replace the high end original Toyota part with cheap, new Chinese auto parts store part, just because it's "new"

I see a lot of folks start replacing all kinds of things looking for their problem, and they replace these very well made Lexus parts with cheap new parts, and are tossing far better quality in the trash than the new parts they are installing!

Some parts are wear parts, such as that temp sensor, as well as plugs, wires, caps, rotors - but on other parts, make sure it's actually bad! - the part you are taking off is likely still far better than the one you are putting on, as far as the larger, long term parts! - The factory service manual has tests for of all these parts, and many of these tests are very quick! - Did you do the test of the coils in the video above (which takes likes 10 seconds?)