My Celica(3sge 1988) Is Dead On Low Rpmsss??????

[abostef6789]

my toyota celica 1988 t-vis 3sge is dead on low rpmss. is it usual to cut off on 7600 rpm.i removed the catalyser does this affect. final question is the oxygen sensor important dont have one tryin to find one thanxxxxxxxxxxxxxxx

[kiasis]

Originally Posted by abostef6789

my toyota celica 1988 t-vis 3sge is dead on low rpmss. is it usual to cut off on 7600 rpm.i removed the catalyser does this affect. final question is the oxygen sensor important dont have one tryin to find one thanxxxxxxxxxxxxxxx

Your O2 sensor is critical to the air/fuel mixture. Without it, your main computer has no way of knowing if you're running rich or lean. It's a critical component of the closed-circuit fuel feedback system.

I assume you mean the engine cuts out at 760 RPM, not 7600 RPM - otherwise you just blew up your engine way past redline.

No, it shouldn't be cutting out at 760 RPM. Not having an oxygen sensor will be a major problem.

Not having a cat-converter means you're pumping a lot of pollutants into the air.

Check out this website, Automotive Training and Resource Site and read up on the fuel system. Go to "technical articles" and start with #20. It's an easy read and where I started not knowing a single thing about my 88 GTS.

[abostef6789]

what i meant that does a catalytic convertor decrease my car's power
plus my engine really cuts off at 7.2 *1000 rpm

am a mechanical engineer(still undergradute) but not that good in celica's

am very thankful for ur previous reply ur so kind

[kiasis]

Getting rid of the Cat and installing a straight pipe might increase your power very slightly. What people complain about with the Cat is back pressure. Too much back pressure gets in the way of the engine exhausting efficiently. However, I had my exhaust back pressure tested in front of the Cat and behind the Cat. The difference was around 2 psi. You might gain a little power from not having the Cat, but probably not enough to notice a difference. Real HP gains involve upgrading the entire fuel injection system from pump to injectors to main computer. Then you might have a good enough reason to up-size your exhaust pipe and install a straight pipe in place of the Cat.

The thing is, our cars are very much controlled by the main computer (ECU) taking in all sorts of data from the dozen or so sensors and constantly adjusting the A-F mix based on the different sensor readings. The computer is constantly trying to achieve the optimum A/F mix of 14.7:1. So adjusting just one or two of the system pieces doesn't really work very well, as the computer will simply adjust things to bring the system back into the pre-programmed range of operation.

Before you know it, you're swapping in different cams w/ more progressive lifter patterns, pistons with higher compression ratings, crankshafts with longer stroke durations, etc, etc. In other words, huge $$$.

A lot of guys have swapped in different fuel injectors that deliver a ton more fuel. Problem is, you have to first upgrade the fuel pump to get all that extra fuel out of the tank. Then you have to change your air flow meter and sensor to allow much more air to enter the vehicle. Then you have to make sure your exhaust system can get rid of all that extra exhaust or else you have too much back pressure. Since your O2 sensor is part of the system designed to regulate the A/F mixture, you'll need to get a special wide-band, programmable O2.

I've spent my money on rebuilding my 3SGE back to top factory specs and making sure every component is operating at max potential. Then I upgraded the brakes and suspension. If I want a ton more HP, it's either drop in the 3SGTE, a later generation model of the 3SGE, or spend $4-5K on mods to my existing engine - hardly worth it.

As for your RPM cut-off, consider yourself lucky. Basically, that's the safety feature built in to keep you from shooting pistons out the top of your engine and piston rods out the bottom of your engine (or worse, through the fire wall and back into the passanger compartment). That red-line is there for your protection (body and pocket book). Unless you've done a lot of engine upgrades (HC pistons, rings, rods, crank, camshafts, etc) you don't wanna be messing around at 7600 RPM very much.

[abostef6789]

can i remap my ecu as others do in new cars
that gives alot power and acceleration thanx anyway

[McKenzieJr18]

you can but u still need to upgrade ur internals

[abostef6789]

sry didnt get ur point sir ???
can it be remapped on a scanner or should i replace the chips with a custome one . coz remapping gains much horsepower

[kiasis]

You won't get any more power from remapping unless the rest of the system can handle the remapping. That means upgrading fuel pump, fuel injectors, pistons, cams, exhaust, etc. Your entire system is only as good as the weakest link. Changing your ECU and doing nothing will not get you any significant gains at all.

[abostef6789]

so what type of spark plug could i use with a celica 3sge 1988

[kiasis]

I use Denso irdium (IQ16) - love'em.