New plugs and wires are on their way. I went with Iridium NGK plugs that are 1 step colder.

I am starting to wonder if my MAP sensor location could be an issue. I place the 205 MAP sensor where the old 185 sensor went. So that means I had to extend the hose to the other side of the intake manifold. I am starting to wonder if this could cause the sensor to read incorrectly.

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Coldiron (Cold - Iron)
1992 Celica Gt4 RC Conv. St205 swap

http://www.noritoy.com

Can you post a picture of the area around the intake manifold as it is now

Someone might spot an issue

Also, if you scout around the big green books (google for celicatech bgb) there's a section in the EFI bit about diagnosing issues using a volt meter. There's definitely an entry for the MAP sensor and all the other sensors. It's possible that something subtle is not quite right on the ECU pinout.
Alsoconsider throwing it on the dyno for a diagnostic fuel run. Or matbe invest in a wideband so you can do it yourself

did you check that the old oxygen senor had failed , as its quite possible it was okay.

check the map sensor using a scope same as O2 sensor, a dvm or even a data logger over the entire range under test conditions... old units can produce poor signal constant , though have only come across one denso unit that failed.

check for bad earths making sure all sensors are working from ecu plug point.

what about fuel pressure, air leaks both engine intake and exhaust man.

The old O2 sensor gave no reading at the diagnostics port, but the new one does.

I am unsure of the fuel economy as it is now, but the idle has a slight dip in it after letting off the gas, and sometimes it runs low on the idle.

You can see the MAP sensor in this pic to the right of the intake manifold in front of the oem strut bar.

Once my new plugs and wires get here I am going to relocate it to the other side and run a much shorter hose.



As for grounding. I added an extra ground to the alternator, the gear box and the igniter.

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Coldiron (Cold - Iron)
1992 Celica Gt4 RC Conv. St205 swap

http://www.noritoy.com

Maybe my idle isn't low.
http://www.gtfours.co.uk/
This website says my idle should be ~700rpm. It used to idle ~900-1100 rpm, now its in the 700 range. It just seems low to me.

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Coldiron (Cold - Iron)
1992 Celica Gt4 RC Conv. St205 swap

http://www.noritoy.com

they do seem very low to me too. Mine used to idle around 700 though

Mine idles between 900-700. It sort of fluxuates and when it goes down to 700 it seems to vibrate the car a bit. I wll report back once I gave the car a good tune up.

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Coldiron (Cold - Iron)
1992 Celica Gt4 RC Conv. St205 swap

http://www.noritoy.com

I changed the plugs, and wires today, and I also moved the map sensor to the other side of the car. The hose is less than 5" where is was 1.5-2 feet.

The car is more responsive now, and even though it still seems slightly over geared, its not near as gutless as it was in the mid range.

Turns out my old "pregapped" plugs were gaped to ~040. Should have been ~032.

Here is a pic of the old plug. Lots of carbon, and the tip is white. Use a cheap set of plugs when setting you car up, then once its done get new or better plugs.

So now it looks like the car is done. I filled up with fuel and now I will watch how the fuel economy has changed.

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Coldiron (Cold - Iron)
1992 Celica Gt4 RC Conv. St205 swap

http://www.noritoy.com

I hate the fuel gauge in this car. It bounces around a lot depending on my driving. If its right, I burned off the 1st 1/4 of a tank in 30 miles. I am going to test another 1/4 of a tank and see if my millage did improve.

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Coldiron (Cold - Iron)
1992 Celica Gt4 RC Conv. St205 swap

http://www.noritoy.com

I learned today that my fuel tank is leaking... The hill I park my car on tilts it just enough to where it does not leak when parked. I had some damage from running the dragon today, and when I pulled over to check it I saw gas leaking out. This explains why I burned thru 1/4 tank in a 12 mile run.

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Coldiron (Cold - Iron)
1992 Celica Gt4 RC Conv. St205 swap

http://www.noritoy.com

It seems that you can get a problem with either the filler neck for the tank or from the hoses leading away from the tank...

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Kris
95 ST205 - slept for 10 years, now waking up...
Avensis
http://www.gtfours.co.uk
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Turbocharging - the replacement for displacement

Something I have been curious about:

Is the oem EGT probe needed or effect running conditions and ecconomy? If not, can it be modified to work with standard apexi egt gauges?

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Coldiron (Cold - Iron)
1992 Celica Gt4 RC Conv. St205 swap

http://www.noritoy.com

That probe is not an EGT one as such

It's more of a CAT OK/CAT not OK signal for the dash warning lamp so no it can't really be made to work

It's fine to ditch this probe but EGT measurements made there will be very different to actual EGTs

As far as I know the EGT/CAT sensor is in fact more of a switch and only drives the little light on the dash.

When I had my ST185 I removed the cat to replace with a straight pipe, i just disconnected the sensor with no ill effects.

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GT4DC Events Co-ordinator
1996 ST205 UK

So it seems it is leaking at the fuel pump on the inner fuel pipe connection. I am trying to get to it now so I can either tighten it or replace it.

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Coldiron (Cold - Iron)
1992 Celica Gt4 RC Conv. St205 swap

http://www.noritoy.com