strongsail

I keep my service manuals in the bathroom - only place I can get some reading done - and in my last visit, I had a look at the engine troubleshooting section - if the ecu isn't giving any codes, the matrix chart for "poor drivability - poor acceleration" says to check the following things, in this order:

1. Switch condition circuit (idle switch, park/neutral switch, A/C switch)

2. VAF meter circuit

3. Injector circuit

4. Fuel pump control circuit

5. Ignition signal circuit

6. Ignition coil

7. Distributor

8. Spark plugs

9. ECT (the tranny)

This sequence assumes you already know you have good airflow (clean filter), correct timing at idle, and correct fuel pressure.

So, now you have a LOT more questions than answers. You're welcome, glad to be of help.

Hermosa

PWR ECT makes it stay in high RPMS longer

Lvangundy

Could be the TPS.

It goes like on a 0-9 scale. Maybe it's only hitting like 6 or something. Could be alot of things..

dunn378

i have a 91 LS and today was the first time i really floored it coming out of a toll booth and to my surprize the car shiftred right at the redline in the normal mode!!!! the funny thing is i think i need a tps sensor. needless to say i was very very happy. i wonder what will happen when i put it in power mode!!!

London Bill

HID (her in doors), wanted me to take her out in the Soarer today as I spend more time working on it rather than driving it, but as it was a nice British Sunday (not raining/snowing) I agreed.

Wind the boost up to 18psi, strap the old girl in tight and off we go ignoring the motorways and taking the little two lane blacktops down to the coast. In the depths of Hampshire (Meon Valley for those that know), I managed a full throttle 3rd to O/D gear change, thats somewhere around 130mph at about 6,500rpm, I expect nothing less.

Never a day goes by when I am in the beast that I dont manage 2nd to 3rd change at full throttle doing 82mph, if my box started short shifting I would notice it straight away but I suspect you may need to have your box looked at if it refuses to hold on to a gear beyond 4,500rpm, could be a line pressure issue or faulty electronics/sensors.

xBlkGs430x

ok, another drive. i put the car in 2nd gear and floored it. 1st gear shifts in 4300rpm. im going to the shop in the morning, im going to have the mechanic check the car out and c if he can find anything. hopefully i can get things figuered out.

SC300Es

why are you trying so hard to redline the engine?

just curious...

xBlkGs430x

its not that im trying to redline, but i want to know y i can't redline if i floor it with the ect pwr on,

Pen

With ECT set to Power, and using 2nd gear, there shouldn't be any gear change, it should be locked into 2nd only, unless thats a difference between the US SC400 and the Jap Soarers.

Also, try just putting into first and seeing how high it will rev.

xBlkGs430x

putting it in 1st gear, i can get it to redline, but if the car shifts on its own, i can't get it to redline, the ecu is shifting too early.

strongsail

Not at WOT (Wide Open Throttle) - it should run up to 6250 regardless of where the ECT switch is set.

Pen

Try this from Iain on LSOC:
Remove the battery, overnight, reconnect with the following fuses not in place....EFI and DOME (under the bonnet) reconnect DOME then EFI start car, sit in driveway with handbrake on, go through the shift pattern, slowly, ensuring you stay in each gear for a few seconds.

Hermosa

Yes but it will stay in the upper range longer. That is what is was designed for.

Pen

But that doesn't make sense. Once you get to peak revs, you want to change gear and build revs again, not just sit there.

Under non-WOT conditions, the engine will rev higher before the change so you are more into the power band of the engine instead of saving fuel by changing at lower revs.

Hermosa

Makes sense or not that is how it was designed. Well WOT is WOT and it should always get up there. As far as Lexus says it and from what I experienced the car stays in higher RPMs longer inthe PWR ECT mode.