1992 Lexus ES300 power loss above 1500 RPS

[linthead]

Hi, i'm new to the world of forum talk so here goes! I'm a 72 year old backyard mechanic with
a 1988 celica hatchback and a 1998 Sienna CE of my own. Six weeks ago my grandson dropped off his 1992 Lexus es300 with a severe overheating problem. Other than that it ran good. After working on the most inexpensive problems first, I finally determined it was a blown right side head gasket.
I replaced the head gasket and all other related gaskets, put it back together and started it up. At idle it runs smoothly, but when I increase the RPMS above 1500 it sputters and backfires.It acts like it's not getting enough fuel, or that there's a leak in the system. I replaced the PCV valve and Air filter, rechecked all hoses and lines and ignition timing.
My question is, if the valve timing was off at all would I still get a quick start and good idle??
What else could be the problem??

[linthead]

I'm back with the answer to my "Loss of power problem". It was an misplaced crush washer on the Banjo fitting of Fuel inlet line. Traced it back from the cold start line to the fuel filter.

[Knailgun]

glad you got the kinks worked out....great to see people of all ages loving their toyotas

[Toysrme]

Be sure you put a timing light on it.
Good work!


Clean his entire upper intake.



^^^
That thing, including the ACIS flap hanging from the side (That's his varriable intake).

After 9 months without cleaning they cake up so bad you loose 5 hp. (in turn lowering economy)


If you are really a good grandfather!!!

The ECU grounds the (red/orange/brown) ACIS vacuum switching valve (VSV) so that it opens. This allows vacuum to come from the vacuum tank, up through the VSV, to the ACIS's vacuum actuator. The ECU opens it when : The car is moving/under load (not parked), 3900rpm +, Throttle Position Sensor (TPS) is 50% open or above. That is too late for power. (notice the boost at 4000rpm)



The vacuum tank (it's under the battery). Pull the vacuum hose off that runs between it and the bown VSV. Connect it on the ACIS's actuator, and then put it to one of the three vacuum nipples on the top of the throttlebody. (Let it share with one of the EGR controls. Those are the two nipples facing the passanger side)

Either disconnect the EGR (raising emessions, but forever fixing the massive carbon buildup problem) or take a T fitting (10 cent aquarium fitting works just fine!) and T it into that.

This way it's close idling, but about the time you can pop the throttle plate open, it opens! (even idling)



Now the vacuum tank is un-used, and you can cap it's sorce (a screw in the vacuum line works) and the vacuum tank may be disgarded (saving a few lbs of weight)

[desperate]

I Am Havign The Same Problem. I Have A 92'es 300 And It Recently Started Over Heating. I Got The Upper Radiator Hose, Water Pump, Thermostat, And Head Gasket Replaced. 24 Hours Later It's Still Over Heating. Would My Ac Problem Have Anything To Do With This? Please Reply Im Do Desperate It's Frustrating Because The Palce That Fixed It, Just Replaced Everything Since They Couldn't Find The Problem.

[REN69]

linthead.. I wish you were my grandpa.. hehe.. I need some stuff done on my car.

[Toysrme]

Did you ever mix toyota red coolant with anything else?

[ctgs300]

check the idle speed sensor

[toyotaholic]

After 9 months without cleaning they cake up so bad you loose 5 hp. (in turn lowering economy)

toysrme, how can it be cleaned? seafoam?

[Toysrme]

Seafoam does best cleaning the heads and the back of the intake valves, and abit in the combustion chambers.


If you want to clean the upper intake, you simply gotta take it off.