olsoncam

Help!
CASE: on highway, at highway speeds, upon reaching a hill and incline - car needing more power to maintain speed - car starts to buck a little! If I don't release gas peddle, and continue to attempt to maintain current speed, car will buck harder and thump sound down-under occurs!! Car is basically screaming "enough!".
Car always quickly recovers at a speed and resistance that is happy with. But will always buck again and resist my attempt to accelerate on a hill!
Help!

Recent work (bucking happened before and now still happening AFTER these replacements):
-Replaced ECU this month (March 2017).
-Replaced instrument control panel (March 2017).
-Replace AT vehicle speed sensor 1 (March 2017).

Timing, plugs/wires, fuel pump replaced at 90k.
Currently 120k today.

dicer

In order to check these items.
Fuel
Gas cap vent
Fuel filter
Fuel line for collapsed or bent conditions bad hoses etc.
Fuel pressure
Fuel pump and screen
The problem is the engine is not getting the fuel it needs for that extra power your demanding.

Banshee365

Trans mount?

python

iTrader: (4)

replaced ecu? explain

YODAONE

Bucking.on incline only? Engine AND transmission mounts. Next...what octane fuel are you using?

python

iTrader: (4)

that would not cause bucking..knock sensor issue would...but a light would be on.

YODAONE

So what happens on a steep incline at higher elevatuons propelling a two ton automobile by a 20+ year old 240 cubic inch engine with typical carbon build up when the knock sensors retard the ignition?

If 87 octane it is not recommended anyway....

olsoncam

thank you dicer! How can I tell if the gas cap needs replacing? It has a good lengthy swooooosh when I open it. Is that good or bad?
im going to assume, like you, that the answer is with the fuel topic. Going to have my throttle body cleaned as well. Hopefully while tracking down the fuel issue I don't spend too much money fixing it.

olsoncam

I purchased a rebuilt ECU from Foreign Auto Computer (business in Texas) and "replaced" my old one with it.

olsoncam

I only use premium fuel 100% of the time since I've owned it (18 months) but who knows what the prior owner used.

olsoncam

would a light come on in a 94 1st generation Lexus? I've heard the computer won't run a code for alot of things in these old cars.

Rdrcr

This also recently started happening on my '94...

Mike

python

iTrader: (4)

it wont buck..it would ping before it would buck